A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of propertie...A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.展开更多
The friction and abrasion characters of yarn play veryimportant roles in the downstream processing and theend-use of products.With the development of rotoryarn and its application in the knitted products,theproblem of...The friction and abrasion characters of yarn play veryimportant roles in the downstream processing and theend-use of products.With the development of rotoryarn and its application in the knitted products,theproblem of abrasion on the machine components causedby the processed rotor yarn has been paid more andmore attentions.This paper deals with the factors effectthe abrasiveness of rotor yarn and the comparison ofabrasive character between rotor yarn and ring yarn.展开更多
Rock abrasiveness is an important factor affecting the tool's lifetime and efficiency in breaking a rock.Characterizing rock abrasiveness helps in the design,optimization,and mean-life prediction of tools.Xray dif...Rock abrasiveness is an important factor affecting the tool's lifetime and efficiency in breaking a rock.Characterizing rock abrasiveness helps in the design,optimization,and mean-life prediction of tools.Xray diffraction,cast thin section analysis,and CERCHAR abrasiveness tests were performed on 18 different sandstones to characterize rock abrasiveness and explore new methods for characterization.The relationship between the mineral composition and microstructure of sandstone and abrasiveness was investigated.The results show that different structural maturities have varying effects on abrasiveness.In addition,the higher the structural maturity,the more the abrasiveness.Furthermore,in sandstones of the same structural maturity,the abrasiveness increases with equivalent quartz content(EQC).The texture coefficient(TC)and CERCHAR abrasiveness index(CAI)of sandstones with the same structural maturity showed a good linear relationship.Moreover,the correlation coefficients considering the combined parameters are above 0.85.Therefore,obtaining the microstructure and mineral composition of sandstone can effectively characterize rock abrasiveness.It also provides a new method for predicting the abrasiveness of the rock in the well.展开更多
Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced...Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced in underwater environments where pollutants can impede the operation of these optical devices,significantly degrading or even compromising their optical properties.The glass catfish,known for its remarkable transparency in water,maintains surface cleanliness and clarity despite exposure to contaminants,impurities abrasion,and hydraulic pressure.Inspired by the glass catfish’s natural attributes,this study introduces a new solution named subaquatic abrasion-resistant and anti-fouling window(SAAW).Utilizing femtosecond laser ablation and electrodeposition,the SAAW is engineered by embedding fine metal bone structures into a transparent substrate and anti-fouling sliding layer,akin to the sturdy bones among catfish’s body.This approach significantly bolsters the window’s abrasion resistance and anti-fouling performance while maintaining high light transmittance.The sliding layer on the SAAW’s surface remarkably reduces the friction of various liquids,which is the reason that SAAW owns the great anti-fouling property.The SAAW demonstrates outstanding optical clarity even after enduring hundreds of sandpaper abrasions,attributing to the fine metal bone structures bearing all external forces and protecting the sliding layer of SAAW.Furthermore,it exhibits exceptional resistance to biological adhesion and underwater pressure.In a green algae environment,the window remains clean with minimal change in transmittance over one month.Moreover,it retains its wettability and anti-fouling properties when subjected to a depth of 30 m of underwater pressure for 30 d.Hence,the SAAW prepared by femtosecond laser ablation and electrodeposition presents a promising strategy for developing stable optical windows in liquid environments.展开更多
An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on t...An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.展开更多
A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion...A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.展开更多
The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusio...The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusion height and random position distribution of abrasive grains on the abrasive wheel surface.This study investigated the distribution of undeformed chip thickness and grinding force considering the non-uniform characteristics of abrasive wheel in the grinding of K4002 nickel-based superalloy.First,a novel grinding force model was established through a kinematic-geometric analysis and a grain-workpiece contact analysis.Then,a series of grinding experiments were conducted for verifying the model.The results indicate that the distribution of undeformed chip thickness is highly consistent with the Gaussian distribution formula.The increase in the grinding depth mainly leads to an increase in the average value of Gaussian distribution.On the contrary,the increase in the workpiece infeed speed or the decrease in the grinding speed mainly increases the standard deviation of Gaussian distribution.The average and maximum errors of the grinding force model are 4.9%and 14.6%respectively,indicating that the model is of high predication accuracy.展开更多
The TZM alloys with different contents of ZrO_(2)were prepared by powder metallurgy and rolling,and the grain size,hardness,and abrasive wear resistance of TZM alloy were studied.The abrasive wear test of TZM alloy wa...The TZM alloys with different contents of ZrO_(2)were prepared by powder metallurgy and rolling,and the grain size,hardness,and abrasive wear resistance of TZM alloy were studied.The abrasive wear test of TZM alloy was conducted under the conditions of 10,15,and 20 N and abrasive particle sizes of 7,11,18,and 38μm.The results show that the added ZrO_(2)particles in TZM alloy are mainly distributed at the grain boundaries.The grains of TZM alloy containing 1.5wt%ZrO_(2)are significantly refined,and the hardness is increased by 16%.The wear test results show that TZM alloy containing 1.5wt%ZrO_(2)has the lowest mass loss rate and excellent wear resistance under all loads and abrasive sizes,and the wear performance is improved by 12%.The ZrO_(2)with high hardness becomes the main bearer of the load,and as the second-phase,it hinders the abrasive particles from entering the matrix and effectively resists the scratch of the abrasive particles,which is the main reason for the excellent wear resistance.展开更多
As a non-contact ultra-precision machining method,abrasive water jet polishing(AWJP)has signi-ficant application in optical elements processing due to its stable tool influence function(TIF),no subsurface damage and s...As a non-contact ultra-precision machining method,abrasive water jet polishing(AWJP)has signi-ficant application in optical elements processing due to its stable tool influence function(TIF),no subsurface damage and strong adaptability to workpiece shapes.In this study,the effects of jet pressure,nozzle diameter and impinging angle on the distribution of pressure,velocity and wall shear stress in the polishing flow field were systematically analyzed by computational fluid dynamics(CFD)simulation.Based on the Box-Behnken experimental design,a response surface regression model was constructed to investigate the influence mech-anism of process parameters on material removal rate(MRR)and surface roughness(Ra)of fused silica.And experimental results showed that increasing jet pressure and nozzle diameter significantly improved MRR,consistent with shear stress distribution revealed by CFD simulations.However,increasing jet pressure and impinging angle caused higher Ra values,which was unfavorable for surface quality improvement.Genetic algorithm(GA)was used for multi-objective optimization to establish Pareto solutions,achieving concurrent optimization of polishing efficiency and surface quality.A parameter combination of 2 MPa jet pressure,0.3 mm nozzle diameter,and 30°impinging angle achieved MRR of 169.05μm^(3)/s and Ra of 0.50 nm.Exper-imental verification showed prediction errors of 4.4%(MRR)and 3.8%(Ra),confirming the model’s reliabil-ity.This parameter optimization system provides theoretical basis and technical support for ultra-precision polishing of complex curved optical components.展开更多
Because the grinding temperature is high when grinding using conventional disordered grinding wheels,the grinding quality improvement is limited when using single abrasive ordered grinding wheels,and the wheel prepara...Because the grinding temperature is high when grinding using conventional disordered grinding wheels,the grinding quality improvement is limited when using single abrasive ordered grinding wheels,and the wheel preparation process is complex and costly when using microstructured grinding wheels,abrasive groups ordered grinding wheels are widely investigated.However,there is a paucity of systematic analyses and comprehensive reviews focused on abrasive groups ordered grinding wheels.Therefore,this paper defines abrasive groups ordered grinding wheels and classifies them,based on their unique characteristics,into groups such as abrasive blocks ordered grinding wheel,fine grain structured grinding wheel,abrasive clusters ordered grinding wheel,and abrasive fibers ordered grinding wheel.We provide an overview of the latest advances in wheel structures,preparation methods,and abrasive selection for various types of abrasive groups ordered grinding wheels.Furthermore,we conduct a comparative analysis of the existing types,significant advantages,and challenges associated with the four types of abrasive groups ordered grinding wheels.Looking ahead,given the potential of abrasive groups ordered grinding wheels in reducing grinding force and temperature,we recommend further exploration of their application in combination with special processing techniques.This could pave the way for the development of machining processes that are more environmentally friendly,energy-efficient,and precise.展开更多
The use of abrasive waterjets(AWJs)for rock drilling offers advantages in urbanized areas,locations that are vulnerable to damage,and piling operations.However,the overall operational cost of AWJ systems remains high ...The use of abrasive waterjets(AWJs)for rock drilling offers advantages in urbanized areas,locations that are vulnerable to damage,and piling operations.However,the overall operational cost of AWJ systems remains high compared to that of conventional drilling methods,which constrains the long-term industrial application of AWJs.For instance,the abrasive costs account for over 60%of the total process cost,but the recycling of abrasives remaining after drilling could significantly reduce machining costs.In this study,the post-impact characteristics of abrasives were explored,aiming to enhance their recyclability.The physical properties and particle distribution of used abrasives vary depending on the jet energy,ultimately affecting their recyclability and recycling rate.The particle properties of used abrasives(particle size distribution,particle shape,and mean particle size)were compared under different waterjet energy variables(standoff distance(SOD)and water pressure)and test conditions(dry and underwater).Furthermore,the collision stages of the abrasive particles within a waterjet system were classified and analyzed.The results revealed that abrasive fragmentation predominantly occurred due to internal collisions within the mixing chamber.In addition,an attempt was made to optimize the waterjet parameters for an economical and efficient operation.The findings of this study could contribute to enhancing the cost-effectiveness of AWJ systems for rock drilling applications.展开更多
The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0....The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0.05 g/cm3) of the composite produced is lower than that of wood used in this field. The material has low porosity (9.8%) and is less absorbent (12.61%) than wood. The result of the thermal conductivity test by the hot plane method shows that this composite can contribute to the internal thermal insulation (an example of thermal conductivity is 0.32W/m.K) of floating boats. The mechanical tests of compression (young modulus is 22.86 GPa), resilience (1.238 J/Cm2) and hardness (233.04 BH30-2.5/187.5-15s) show that this composite is much harder and more absorbent than many wood and bio-composite materials used in the construction of pleasure boats. The abrasion test (0.005349) shows that this composite could well resist friction with the beach.展开更多
Medium-manganese steel exhibits excellent strength and toughness,which are essential features in wear resistance applications.This study examines the impact of annealing temperature on impact abrasive wear.The results...Medium-manganese steel exhibits excellent strength and toughness,which are essential features in wear resistance applications.This study examines the impact of annealing temperature on impact abrasive wear.The results have indicated that samples annealed at different temperatures display plowing and fatigue wear effects.In the initial wear stage,the hightemperature annealed steel outperforms samples annealed at a lower temperature in terms of anti-plowing wear performance.This phenomenon is mainly due to the lower initial hardness of the samples subjected to low-temperature annealing.However,with prolonged wear time,the low-temperature annealed samples exhibit improved plowing wear performance,which is ascribed to a refinement of the lamellar microstructure and an increased residual austenite(RA),which enhances the work hardening effect,improving the hardness of the worn surface.The low-temperature annealed samples consistently delivered superior fatigue wear performance when compared with samples annealed at the higher temperature.The latter effect may be attributed to two factors.Firstly,the finer lamellar microstructure in the low-temperature annealed samples,coupled with greater RA,results in transformation-induced plasticity or twin-induced plasticity effect that hinders crack formation and propagation.Secondly,the low-temperature annealed samples form nanoscale equiaxed grains near the worn surface during the wear process.These grains can withstand crack driving forces in fine-grained regions,suppressing the formation and propagation of cracks.展开更多
To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragred...To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragreducing additive.The effects of feed rate(50-300 mm/min),polymer concentration(0-0.5 g/L),and nozzle spacing(4-12 mm)on kerf width and surface roughness are systematically investigated through an orthogonal experimental design.Results reveal that feed rate emerges as themost significant factor(p<0.01),followed by PAM concentration and nozzle spacing.The optimal set of parameters,comprising a 200 mm/min feed rate,0.3 g/L PAM concentration,and 6mmnozzle spacing,achieves the narrowest kerf width(0.867 mm)and the lowest surface roughness(10.220μm).Analysis of the underlying mechanisms demonstrates that PAMenhances the energy efficiency of the jet by suppressing turbulent pulsations and increasing fluid viscoelasticity,thereby minimizing energy loss during the cutting process.展开更多
During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological envir...During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.展开更多
To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate grad...To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate gradation, sand ratio, fly ash content, and superplasticizer dosage. Based on the optimized mix, the combined effects of an abrasion-resistance enhancement admixture (AEA) and silica fume (SF) on the abrasion resistance of self-compacting concrete (SCC) were examined. The results demonstrated that the appropriate incorporation of AEA and SF significantly improved the abrasion resistance of SCC without compromising its workability. The proposed mix design not only achieves superior abrasion resistance but also provides practical guidance for the material design and engineering application of durable hydraulic concrete in harsh environments. Future research will focus on comprehensive durability assessments by simulating extreme hydraulic conditions, including sustained exposure to high-velocity sediment-laden flows, repeated freeze-thaw cycles, and corrosive salt spray environments, to thoroughly evaluate the long-term performance evolution of abrasion-resistant self-compacting concrete. Meanwhile, advanced microstructural analytical methods should be applied toelaborate the synergistic mechanisms of abrasion-resistance enhancement admixture (AEA), silica fume (SF), and steel fibers in altering the hydration product formation, optimizing the distribution of pore structure, and strengthening interfacial transition zones, to establish a solid scientific foundation for the development of high-performance composite materials.展开更多
Seven sets of concrete containing different mass ratios of nano-SiO_(2)(0%-5.0%)and nano-CaCO_(3)(0%-1.5%)were designed.A total of 28 concrete cube specimens cured for 7 and 28 days were tested for compressive strengt...Seven sets of concrete containing different mass ratios of nano-SiO_(2)(0%-5.0%)and nano-CaCO_(3)(0%-1.5%)were designed.A total of 28 concrete cube specimens cured for 7 and 28 days were tested for compressive strength(14 specimens)and split tensile strength(14 specimens),while 7 cylindrical specimens cured for 28 days were tested for impact resistance.The impact resistance of the concrete specimens was quantitatively analyzed by using impact strength(f_(a))and wear rate(L_^(a)),and the effect of dual incorporation of nano-SiO_(2)and nano-CaCO_(3)on the microstructure of concrete was further investigated by XRD and SEM.The experimental results indicate that the incorporation of 5.0%nano-SiO_(2)and 1.5%nano-CaCO_(3)improves the mechanical properties and impact resistance of concrete most significantly,and the compressive strength,split tensile strength,and impact resistance increase by around 37.80%,35.31%,and 183.36%,respectively,compared with that of ordinary concrete.At the microscopic level,nano-SiO_(2)reacts with C-H in a secondary hydration reaction to increase the number of C-S-H gels,which improves the pore structure in the matrix and favorably enhances the adhesion between aggregate and cement paste in the weakened layer,thus improving the abrasion resistance of concrete.展开更多
The microstructural evolution,mechanical properties,and wear behavior of medium manganese steels(MMSs)with varying aluminum(Al)contents were investigated.It was observed that the microstructure of MMS transferred from...The microstructural evolution,mechanical properties,and wear behavior of medium manganese steels(MMSs)with varying aluminum(Al)contents were investigated.It was observed that the microstructure of MMS transferred from a predominantly martensitic phase(in the Al-free state)to a ferrite/martensite or ferrite/austenite duplex structure with increasing Al content.The hardness of MMS decreased with Al addition,while the impact absorbed energy and yield strength were optimized in 2%Al-containing variant.Frictional wear tests demonstrated that 2 wt.%Al-MMS exhibited superior wear resistance due to the twinning-induced plasticity effect.Conversely,under impact abrasion wear conditions,the Al-free MMS displayed the lowest mass loss,attributing to high surface hardness and remarkable work hardening capacity.These findings indicates that Al content-tailored MMSs can be selectively applied in different wear environments,with 2 wt.%Al-MMS being optimal for static load conditions and the Al-free MMS for dynamic impact abrasion scenarios.展开更多
Machined surface integrity of workpieces in harsh environments has a remarkable influence on their performance.However,the complexity of the new type of machining hinders a comprehensive understanding of machined surf...Machined surface integrity of workpieces in harsh environments has a remarkable influence on their performance.However,the complexity of the new type of machining hinders a comprehensive understanding of machined surface integrity and its formation mechanism,thereby limiting the study of component performance.With increasing demands for high-quality machined workpieces in aerospace industry applications,researchers from academia and industry are increasingly focusing on post-machining surface characterization.The profile grinding test was conducted on a novel single-crystal superalloy to simulate the formation of blade tenons,and the obtained tenons were characterized for surface integrity elements under various operating conditions.Results revealed that ultrasonic vibration-assisted grinding(UVAG)led to multiple superpositions of abrasive grain trajectories,causing reduced surface roughness(an average reduction of approximately29.6%)compared with conventional grinding.After examining the subsurface layer of UVAG using transmission electron microscopy,the results revealed that the single-crystal tenon grinding subsurface layer exhibited a gradient evolution from the near-surface to the substrate.This evolution was characterized by an equiaxed nanocrystalline layer measuring 0.34μm,followed by a submicrocrystalline grain-forming zone spanning 0.6μm and finally,a constituent phase-twisted dis-torted deformation zone over 0.62μm.Under normal grinding conditions,the tenon exhibited low surface hardening(not exceeding 15%),and residual compressive stresses were observed on its surface.In cases where grinding burns occurred,a white layer appeared on the tenon's surface,which demonstrated varying thicknesses along the teeth from top to root due to thermal-force-structural coupling effects.Additionally,these burns introduced residual tensile stresses on the tenon's surface,potentially substantially affecting its fatigue life.This paper enhances our understanding of UVAG processes and establishes a foundation for their application in manufacturing singlecrystal turbine blades for next-generation aero-turbine engines.展开更多
Submerged Abrasive Waterjet Peening(SAWJP)shows great application potential in augmenting the fatigue properties of metallic parts.Thus,the present work aims to investigate the influence of SAWJP on the Surface Integr...Submerged Abrasive Waterjet Peening(SAWJP)shows great application potential in augmenting the fatigue properties of metallic parts.Thus,the present work aims to investigate the influence of SAWJP on the Surface Integrity(SI)and Fretting Fatigue(FF)properties of Inconel 718(IN718)superalloy and illustrate the microstructural evolution,FF life improvement,and fretting wear mechanism.First,the SI of the IN718 specimen was examined following treatment via SAWJP.Results showed that the specimen subjected to SAWJP formed a total plastic deformation layer of 56μm.The maximum microhardness and Compressive Residual Stress(CRS)measured across the depth of the SAWJP-treated specimens exhibited an increase in values ranging between 522 HV and 541 HV and 1171–1380 MPa,respectively.The FF test results of the specimen before and after SAWJP treatment at ambient temperatures indicated that the FF life of the SAWJP-treated specimen surpassed that of the as-received specimen by a factor of 2.81.The examination of the FF fracture,contact surface,and crack propagation behavior revealed the crucial factors contributing to the enhanced FF resistance of the IN718 specimen,including the gradient nanostructure characterized by ultra-refined grains,substantial CRS,and elevated microhardness,which were all induced by the SAWJP treatment.展开更多
文摘A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.
文摘The friction and abrasion characters of yarn play veryimportant roles in the downstream processing and theend-use of products.With the development of rotoryarn and its application in the knitted products,theproblem of abrasion on the machine components causedby the processed rotor yarn has been paid more andmore attentions.This paper deals with the factors effectthe abrasiveness of rotor yarn and the comparison ofabrasive character between rotor yarn and ring yarn.
基金support from the National Natural Science Foundation of China(Grant No.U20A20266)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(Grant No.2020CX040103)Sichuan Province Key R&D Program(Grant No.22SYSX0035).
文摘Rock abrasiveness is an important factor affecting the tool's lifetime and efficiency in breaking a rock.Characterizing rock abrasiveness helps in the design,optimization,and mean-life prediction of tools.Xray diffraction,cast thin section analysis,and CERCHAR abrasiveness tests were performed on 18 different sandstones to characterize rock abrasiveness and explore new methods for characterization.The relationship between the mineral composition and microstructure of sandstone and abrasiveness was investigated.The results show that different structural maturities have varying effects on abrasiveness.In addition,the higher the structural maturity,the more the abrasiveness.Furthermore,in sandstones of the same structural maturity,the abrasiveness increases with equivalent quartz content(EQC).The texture coefficient(TC)and CERCHAR abrasiveness index(CAI)of sandstones with the same structural maturity showed a good linear relationship.Moreover,the correlation coefficients considering the combined parameters are above 0.85.Therefore,obtaining the microstructure and mineral composition of sandstone can effectively characterize rock abrasiveness.It also provides a new method for predicting the abrasiveness of the rock in the well.
基金supported by the National Science Foundation of China under Grant Nos(Nos.12127806,62175195)the International Joint Research Laboratory for Micro/Nano Manufacturing and Measurement Technologies。
文摘Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced in underwater environments where pollutants can impede the operation of these optical devices,significantly degrading or even compromising their optical properties.The glass catfish,known for its remarkable transparency in water,maintains surface cleanliness and clarity despite exposure to contaminants,impurities abrasion,and hydraulic pressure.Inspired by the glass catfish’s natural attributes,this study introduces a new solution named subaquatic abrasion-resistant and anti-fouling window(SAAW).Utilizing femtosecond laser ablation and electrodeposition,the SAAW is engineered by embedding fine metal bone structures into a transparent substrate and anti-fouling sliding layer,akin to the sturdy bones among catfish’s body.This approach significantly bolsters the window’s abrasion resistance and anti-fouling performance while maintaining high light transmittance.The sliding layer on the SAAW’s surface remarkably reduces the friction of various liquids,which is the reason that SAAW owns the great anti-fouling property.The SAAW demonstrates outstanding optical clarity even after enduring hundreds of sandpaper abrasions,attributing to the fine metal bone structures bearing all external forces and protecting the sliding layer of SAAW.Furthermore,it exhibits exceptional resistance to biological adhesion and underwater pressure.In a green algae environment,the window remains clean with minimal change in transmittance over one month.Moreover,it retains its wettability and anti-fouling properties when subjected to a depth of 30 m of underwater pressure for 30 d.Hence,the SAAW prepared by femtosecond laser ablation and electrodeposition presents a promising strategy for developing stable optical windows in liquid environments.
基金supported by the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the Chongqing Science Fund for Distinguished Young Scholars(Grant No.CSTB2022NSCQJQX0028)the National Natural Science Foundation of China(Grant Nos.U23A20597,52274112).
文摘An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.
基金financially supported by the National Key Research and Development Program of China(Grant No.2023YFC2811600)the National Natural Science Foundation of China(Grant Nos.52301349 and 52088102)+1 种基金the Qingdao Post-Doctorate Science Fund(No.QDBSH20220202070)the Major Scientific and Technological Innovation Project of Shandong Province(Grant No.2019JZZY010820).
文摘A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(Nos.P2022-AB-Ⅳ-002-001 and P2023-B-Ⅳ-003-001)+3 种基金the Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(No.JSKL2223K01)the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Superior Postdoctoral Project of Jiangsu Province(No.2022ZB215)the Henan Science and Technology Public Relations Project(No.212102210445).
文摘The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusion height and random position distribution of abrasive grains on the abrasive wheel surface.This study investigated the distribution of undeformed chip thickness and grinding force considering the non-uniform characteristics of abrasive wheel in the grinding of K4002 nickel-based superalloy.First,a novel grinding force model was established through a kinematic-geometric analysis and a grain-workpiece contact analysis.Then,a series of grinding experiments were conducted for verifying the model.The results indicate that the distribution of undeformed chip thickness is highly consistent with the Gaussian distribution formula.The increase in the grinding depth mainly leads to an increase in the average value of Gaussian distribution.On the contrary,the increase in the workpiece infeed speed or the decrease in the grinding speed mainly increases the standard deviation of Gaussian distribution.The average and maximum errors of the grinding force model are 4.9%and 14.6%respectively,indicating that the model is of high predication accuracy.
基金National Natural Science Foundation of China(U1804124)Key Scientific and Technological Project of Henan Province(202102210014)。
文摘The TZM alloys with different contents of ZrO_(2)were prepared by powder metallurgy and rolling,and the grain size,hardness,and abrasive wear resistance of TZM alloy were studied.The abrasive wear test of TZM alloy was conducted under the conditions of 10,15,and 20 N and abrasive particle sizes of 7,11,18,and 38μm.The results show that the added ZrO_(2)particles in TZM alloy are mainly distributed at the grain boundaries.The grains of TZM alloy containing 1.5wt%ZrO_(2)are significantly refined,and the hardness is increased by 16%.The wear test results show that TZM alloy containing 1.5wt%ZrO_(2)has the lowest mass loss rate and excellent wear resistance under all loads and abrasive sizes,and the wear performance is improved by 12%.The ZrO_(2)with high hardness becomes the main bearer of the load,and as the second-phase,it hinders the abrasive particles from entering the matrix and effectively resists the scratch of the abrasive particles,which is the main reason for the excellent wear resistance.
文摘As a non-contact ultra-precision machining method,abrasive water jet polishing(AWJP)has signi-ficant application in optical elements processing due to its stable tool influence function(TIF),no subsurface damage and strong adaptability to workpiece shapes.In this study,the effects of jet pressure,nozzle diameter and impinging angle on the distribution of pressure,velocity and wall shear stress in the polishing flow field were systematically analyzed by computational fluid dynamics(CFD)simulation.Based on the Box-Behnken experimental design,a response surface regression model was constructed to investigate the influence mech-anism of process parameters on material removal rate(MRR)and surface roughness(Ra)of fused silica.And experimental results showed that increasing jet pressure and nozzle diameter significantly improved MRR,consistent with shear stress distribution revealed by CFD simulations.However,increasing jet pressure and impinging angle caused higher Ra values,which was unfavorable for surface quality improvement.Genetic algorithm(GA)was used for multi-objective optimization to establish Pareto solutions,achieving concurrent optimization of polishing efficiency and surface quality.A parameter combination of 2 MPa jet pressure,0.3 mm nozzle diameter,and 30°impinging angle achieved MRR of 169.05μm^(3)/s and Ra of 0.50 nm.Exper-imental verification showed prediction errors of 4.4%(MRR)and 3.8%(Ra),confirming the model’s reliabil-ity.This parameter optimization system provides theoretical basis and technical support for ultra-precision polishing of complex curved optical components.
基金Supported by National Natural Science Foundation of China(Grant No.52175401)Hunan Provincial Postgraduate Scientific Research Innovation Project(Grant No.QL20230244)+1 种基金Enterprise Innovation and Development Joint Program of National Natural Science Foundation of China(Grant No.U20B2032)Hunan Provincial Science and Technology Innovation Program(Grant No.2022RC1050).
文摘Because the grinding temperature is high when grinding using conventional disordered grinding wheels,the grinding quality improvement is limited when using single abrasive ordered grinding wheels,and the wheel preparation process is complex and costly when using microstructured grinding wheels,abrasive groups ordered grinding wheels are widely investigated.However,there is a paucity of systematic analyses and comprehensive reviews focused on abrasive groups ordered grinding wheels.Therefore,this paper defines abrasive groups ordered grinding wheels and classifies them,based on their unique characteristics,into groups such as abrasive blocks ordered grinding wheel,fine grain structured grinding wheel,abrasive clusters ordered grinding wheel,and abrasive fibers ordered grinding wheel.We provide an overview of the latest advances in wheel structures,preparation methods,and abrasive selection for various types of abrasive groups ordered grinding wheels.Furthermore,we conduct a comparative analysis of the existing types,significant advantages,and challenges associated with the four types of abrasive groups ordered grinding wheels.Looking ahead,given the potential of abrasive groups ordered grinding wheels in reducing grinding force and temperature,we recommend further exploration of their application in combination with special processing techniques.This could pave the way for the development of machining processes that are more environmentally friendly,energy-efficient,and precise.
基金supported by the Korea Agency for Infrastructure Technology Advancement(KAIA)grant funded by the Ministry of Land,Infrastructure and Transport(Grant No.RS-2023-00245334)。
文摘The use of abrasive waterjets(AWJs)for rock drilling offers advantages in urbanized areas,locations that are vulnerable to damage,and piling operations.However,the overall operational cost of AWJ systems remains high compared to that of conventional drilling methods,which constrains the long-term industrial application of AWJs.For instance,the abrasive costs account for over 60%of the total process cost,but the recycling of abrasives remaining after drilling could significantly reduce machining costs.In this study,the post-impact characteristics of abrasives were explored,aiming to enhance their recyclability.The physical properties and particle distribution of used abrasives vary depending on the jet energy,ultimately affecting their recyclability and recycling rate.The particle properties of used abrasives(particle size distribution,particle shape,and mean particle size)were compared under different waterjet energy variables(standoff distance(SOD)and water pressure)and test conditions(dry and underwater).Furthermore,the collision stages of the abrasive particles within a waterjet system were classified and analyzed.The results revealed that abrasive fragmentation predominantly occurred due to internal collisions within the mixing chamber.In addition,an attempt was made to optimize the waterjet parameters for an economical and efficient operation.The findings of this study could contribute to enhancing the cost-effectiveness of AWJ systems for rock drilling applications.
文摘The mechanical, physical and thermal characterization of a composite made from woven raffia fiber vinifiera molded in epoxy resin intended for shipbuilding shows that the density (0.5 g/cm3 with a relative error of 0.05 g/cm3) of the composite produced is lower than that of wood used in this field. The material has low porosity (9.8%) and is less absorbent (12.61%) than wood. The result of the thermal conductivity test by the hot plane method shows that this composite can contribute to the internal thermal insulation (an example of thermal conductivity is 0.32W/m.K) of floating boats. The mechanical tests of compression (young modulus is 22.86 GPa), resilience (1.238 J/Cm2) and hardness (233.04 BH30-2.5/187.5-15s) show that this composite is much harder and more absorbent than many wood and bio-composite materials used in the construction of pleasure boats. The abrasion test (0.005349) shows that this composite could well resist friction with the beach.
基金financial support to the Application Foundation Frontier Project of the Major Program(JD)of Hubei Province(2023BAA019-4)the National Natural Science Foundation of China(U20A20279,12072245,52071238)+2 种基金the Science and Technology Program of Guangxi Province(AA22068080)the Key Research and Development Program of Hubei Province(2021BAA057)the Taishan Industry-Leading Talent Project Special Funding and Subject Innovation and Talent Introduction Program in Colleges and Universities(111 programs No.D18018)。
文摘Medium-manganese steel exhibits excellent strength and toughness,which are essential features in wear resistance applications.This study examines the impact of annealing temperature on impact abrasive wear.The results have indicated that samples annealed at different temperatures display plowing and fatigue wear effects.In the initial wear stage,the hightemperature annealed steel outperforms samples annealed at a lower temperature in terms of anti-plowing wear performance.This phenomenon is mainly due to the lower initial hardness of the samples subjected to low-temperature annealing.However,with prolonged wear time,the low-temperature annealed samples exhibit improved plowing wear performance,which is ascribed to a refinement of the lamellar microstructure and an increased residual austenite(RA),which enhances the work hardening effect,improving the hardness of the worn surface.The low-temperature annealed samples consistently delivered superior fatigue wear performance when compared with samples annealed at the higher temperature.The latter effect may be attributed to two factors.Firstly,the finer lamellar microstructure in the low-temperature annealed samples,coupled with greater RA,results in transformation-induced plasticity or twin-induced plasticity effect that hinders crack formation and propagation.Secondly,the low-temperature annealed samples form nanoscale equiaxed grains near the worn surface during the wear process.These grains can withstand crack driving forces in fine-grained regions,suppressing the formation and propagation of cracks.
基金supported by the National Natural Science Foundation of China(grant number:52006061)the Key R&D Program of Hunan Province(grant number:2024AQ2001)+2 种基金Scientific Research Program of Hunan Provincial Department of Education(grant number:22B0840)Natural Science Foundation of Hunan Province(grant number:2023JJ50483)Hunan University of Humanities,Science and Technology Graduate Student Research and Innovation Program(ZSCX2024Y06,ZSCX2024Y01).
文摘To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragreducing additive.The effects of feed rate(50-300 mm/min),polymer concentration(0-0.5 g/L),and nozzle spacing(4-12 mm)on kerf width and surface roughness are systematically investigated through an orthogonal experimental design.Results reveal that feed rate emerges as themost significant factor(p<0.01),followed by PAM concentration and nozzle spacing.The optimal set of parameters,comprising a 200 mm/min feed rate,0.3 g/L PAM concentration,and 6mmnozzle spacing,achieves the narrowest kerf width(0.867 mm)and the lowest surface roughness(10.220μm).Analysis of the underlying mechanisms demonstrates that PAMenhances the energy efficiency of the jet by suppressing turbulent pulsations and increasing fluid viscoelasticity,thereby minimizing energy loss during the cutting process.
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20231497)Jiangsu Provincial Post Graduate Research&Practice Innovation Program(Grant No.KYCX25_2982)+2 种基金China University of Mining and Technology Graduate Innovation Program(Grant No.2025WLKXJ094)National Natural Science Foundation of China(Grant No.51975573),National Key R&D Program of China(Grant No.2022YFC2905600)Priority Academic Program Development of Jiangsu Higher Education Institute of China.
文摘During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.
基金supported by the National Natural Science Foundation of China(No.52179137).
文摘To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate gradation, sand ratio, fly ash content, and superplasticizer dosage. Based on the optimized mix, the combined effects of an abrasion-resistance enhancement admixture (AEA) and silica fume (SF) on the abrasion resistance of self-compacting concrete (SCC) were examined. The results demonstrated that the appropriate incorporation of AEA and SF significantly improved the abrasion resistance of SCC without compromising its workability. The proposed mix design not only achieves superior abrasion resistance but also provides practical guidance for the material design and engineering application of durable hydraulic concrete in harsh environments. Future research will focus on comprehensive durability assessments by simulating extreme hydraulic conditions, including sustained exposure to high-velocity sediment-laden flows, repeated freeze-thaw cycles, and corrosive salt spray environments, to thoroughly evaluate the long-term performance evolution of abrasion-resistant self-compacting concrete. Meanwhile, advanced microstructural analytical methods should be applied toelaborate the synergistic mechanisms of abrasion-resistance enhancement admixture (AEA), silica fume (SF), and steel fibers in altering the hydration product formation, optimizing the distribution of pore structure, and strengthening interfacial transition zones, to establish a solid scientific foundation for the development of high-performance composite materials.
基金Funded by the National Natural Science Foundation of China(No.51579195)。
文摘Seven sets of concrete containing different mass ratios of nano-SiO_(2)(0%-5.0%)and nano-CaCO_(3)(0%-1.5%)were designed.A total of 28 concrete cube specimens cured for 7 and 28 days were tested for compressive strength(14 specimens)and split tensile strength(14 specimens),while 7 cylindrical specimens cured for 28 days were tested for impact resistance.The impact resistance of the concrete specimens was quantitatively analyzed by using impact strength(f_(a))and wear rate(L_^(a)),and the effect of dual incorporation of nano-SiO_(2)and nano-CaCO_(3)on the microstructure of concrete was further investigated by XRD and SEM.The experimental results indicate that the incorporation of 5.0%nano-SiO_(2)and 1.5%nano-CaCO_(3)improves the mechanical properties and impact resistance of concrete most significantly,and the compressive strength,split tensile strength,and impact resistance increase by around 37.80%,35.31%,and 183.36%,respectively,compared with that of ordinary concrete.At the microscopic level,nano-SiO_(2)reacts with C-H in a secondary hydration reaction to increase the number of C-S-H gels,which improves the pore structure in the matrix and favorably enhances the adhesion between aggregate and cement paste in the weakened layer,thus improving the abrasion resistance of concrete.
基金supported by the Guangxi Major Science and Technology Project(AB24010120)Young Talent Support Project of Guangzhou Association for Science and Technology(QT-2024-047)+3 种基金Key-Area Research and Development Program of Jiangxi Province(20243BBG71023)GDAS'Project of Science and Technology Development(2023GDASQNRC-0205 and 2024GDASZH-2024010102)Evaluation Project of Guangdong Provincial Key Laboratory(2023B1212060043)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001).
文摘The microstructural evolution,mechanical properties,and wear behavior of medium manganese steels(MMSs)with varying aluminum(Al)contents were investigated.It was observed that the microstructure of MMS transferred from a predominantly martensitic phase(in the Al-free state)to a ferrite/martensite or ferrite/austenite duplex structure with increasing Al content.The hardness of MMS decreased with Al addition,while the impact absorbed energy and yield strength were optimized in 2%Al-containing variant.Frictional wear tests demonstrated that 2 wt.%Al-MMS exhibited superior wear resistance due to the twinning-induced plasticity effect.Conversely,under impact abrasion wear conditions,the Al-free MMS displayed the lowest mass loss,attributing to high surface hardness and remarkable work hardening capacity.These findings indicates that Al content-tailored MMSs can be selectively applied in different wear environments,with 2 wt.%Al-MMS being optimal for static load conditions and the Al-free MMS for dynamic impact abrasion scenarios.
基金supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415,52205475,and 52322510)the Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金the Huaqiao University Engineering Research Center of Brittle Materials Machining(No.2023IME-001)the Natural Science Foundation of Jiangsu Province(No.BK20210295).
文摘Machined surface integrity of workpieces in harsh environments has a remarkable influence on their performance.However,the complexity of the new type of machining hinders a comprehensive understanding of machined surface integrity and its formation mechanism,thereby limiting the study of component performance.With increasing demands for high-quality machined workpieces in aerospace industry applications,researchers from academia and industry are increasingly focusing on post-machining surface characterization.The profile grinding test was conducted on a novel single-crystal superalloy to simulate the formation of blade tenons,and the obtained tenons were characterized for surface integrity elements under various operating conditions.Results revealed that ultrasonic vibration-assisted grinding(UVAG)led to multiple superpositions of abrasive grain trajectories,causing reduced surface roughness(an average reduction of approximately29.6%)compared with conventional grinding.After examining the subsurface layer of UVAG using transmission electron microscopy,the results revealed that the single-crystal tenon grinding subsurface layer exhibited a gradient evolution from the near-surface to the substrate.This evolution was characterized by an equiaxed nanocrystalline layer measuring 0.34μm,followed by a submicrocrystalline grain-forming zone spanning 0.6μm and finally,a constituent phase-twisted dis-torted deformation zone over 0.62μm.Under normal grinding conditions,the tenon exhibited low surface hardening(not exceeding 15%),and residual compressive stresses were observed on its surface.In cases where grinding burns occurred,a white layer appeared on the tenon's surface,which demonstrated varying thicknesses along the teeth from top to root due to thermal-force-structural coupling effects.Additionally,these burns introduced residual tensile stresses on the tenon's surface,potentially substantially affecting its fatigue life.This paper enhances our understanding of UVAG processes and establishes a foundation for their application in manufacturing singlecrystal turbine blades for next-generation aero-turbine engines.
基金financially supported by the National Key Research and Development Project,China(Nos.2018YFA0703300,2022YFB4600019)the National Natural Science Foundation of China(Nos.52275148,52405154)+2 种基金the Innovation Program Phase II of AECC Commercial Aircraft Engine Co.Ltd,China(No.HT-3RJC1053-2020)support by the Postdoctoral Fellowship Program of CPSF,China(No.GZB20240219)the Shanghai Sailing Program,China(No.24YF2708100).
文摘Submerged Abrasive Waterjet Peening(SAWJP)shows great application potential in augmenting the fatigue properties of metallic parts.Thus,the present work aims to investigate the influence of SAWJP on the Surface Integrity(SI)and Fretting Fatigue(FF)properties of Inconel 718(IN718)superalloy and illustrate the microstructural evolution,FF life improvement,and fretting wear mechanism.First,the SI of the IN718 specimen was examined following treatment via SAWJP.Results showed that the specimen subjected to SAWJP formed a total plastic deformation layer of 56μm.The maximum microhardness and Compressive Residual Stress(CRS)measured across the depth of the SAWJP-treated specimens exhibited an increase in values ranging between 522 HV and 541 HV and 1171–1380 MPa,respectively.The FF test results of the specimen before and after SAWJP treatment at ambient temperatures indicated that the FF life of the SAWJP-treated specimen surpassed that of the as-received specimen by a factor of 2.81.The examination of the FF fracture,contact surface,and crack propagation behavior revealed the crucial factors contributing to the enhanced FF resistance of the IN718 specimen,including the gradient nanostructure characterized by ultra-refined grains,substantial CRS,and elevated microhardness,which were all induced by the SAWJP treatment.
