1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7]...1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.展开更多
Binder jet printing(BJP)is a state-of-the-art additive manufacturing technique for producing porous magnesium structures.Porous MgZn-Zr based BJP samples were assessed for corrosion performance in simulated body fluid...Binder jet printing(BJP)is a state-of-the-art additive manufacturing technique for producing porous magnesium structures.Porous MgZn-Zr based BJP samples were assessed for corrosion performance in simulated body fluids by electrochemical and hydrogen evolution measurements.The corrosion rates of the BJP specimens were significantly higher than solid controls,even after accounting for their larger surface areas,suggesting that the BJP microstructure is detrimental to corrosion performance.X-ray computed tomography revealed nonuniform corrosion within the porous structure,with corrosion products forming on the pore walls.Impregnating the pores with hydroxyapatite or polymers greatly improved the corrosion resistance of the BJP samples.展开更多
This study investigates full liquid phase sintering as a process of fabrication parts from WE43(Mg-4wt.%Y-3wt.%RE-0.7wt.%Zr)alloy using binder jetting additive manufacturing(BJAM).This fabrication process is being dev...This study investigates full liquid phase sintering as a process of fabrication parts from WE43(Mg-4wt.%Y-3wt.%RE-0.7wt.%Zr)alloy using binder jetting additive manufacturing(BJAM).This fabrication process is being developed for use in producing structural or biomedical devices.Specifically,this study focused on achieving a near-dense microstructure with WE43 Mg alloy while substantially reducing the duration of sintering post-processing after BJAM part rendering.The optimal process resulted in microstructure with 2.5%porosity and significantly reduced sintering time.The improved sintering can be explained by the presence of Y_(2)O_(3)and Nd_(2)O_(3)oxide layers,which form spontaneously on the surface of WE43 powder used in BJAM.These layers appear to be crucial in preventing shape distortion of the resulting samples and in enabling the development of sintering necks,particularly under sintering conditions exceeding the liquidus temperature of WE43 alloy.Sintered WE43 specimens rendered by BJAM achieved significant improvement in both corrosion resistance and mechanical properties through reduced porosity levels related to the sintering time.展开更多
Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,vol...Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,volume fraction and morphology.Continuous fiber or network reinforcement morphologies are difficult and expensive to manufacture,and the often-used discontinuous particle or whisker reinforcement morphologies result in less effective properties.Here,we demonstrate the formation of a co-continuous ceramic-reinforced metal matrix composite using solid-state processing.Binder jet additive manufacturing(BJAM)was used to print a nickel superalloy part followed by post-processing via reactive sintering to form a continuous carbide reinforcing phase at the particle boundaries.The kinetics of reinforcement formation are investigated in order to develop a relationship between reactive sintering time,temperature and powder composition on the reinforcing phase thickness and volume fraction.To evaluate performance,the wear resistance of the reinforced BJAM alloy 625 MMC was compared to unreinforced BJAM alloy 625,demonstrating a 64%decrease in the specific wear rate under abrasive wear conditions.展开更多
Binder jetting 3D printing is a rapid,cost effective,and efficient moulding/core making process,which can be applied to a large variety of materials.However,it exhibits a relatively low green-part strength.This may ca...Binder jetting 3D printing is a rapid,cost effective,and efficient moulding/core making process,which can be applied to a large variety of materials.However,it exhibits a relatively low green-part strength.This may cause the collapse of the printed parts during de-caking and the pick-up procedure,especially in the case of small-scale structures,such as thin walls,tips,and channels.In this work,polyvinyl alcohol(PVA)was used as the additive in coated sand powder.By exploiting the binding effect between the two composites(thermoplastic phenolic resin and PVA)triggered by the binder,bonding necks firmly form among the sand particles,improving the green-part strength of the coated sand printed parts.Experiments based on the Taguchi method were used to investigate the relationship between the process parameters and the green-part tensile strength.The following set of optimal process parameters was identified:50wt.%alcoholicity of the binder,75%binder saturation,0.36 mm layer thickness and 4.5wt.%PVA content.Further,the effect of such parameters on the green-part tensile strength was determined via statistical analysis.The green part of an engine cylinder head sand pattern with complex cavity structures was printed,and the green-part tensile strength reached 2.31 MPa.Moreover,the ZL301 aluminum alloy impeller shape casting was prepared using sand molds printed with the optimal process parameters.The results confirm that the proposed binder jetting 3D printing process can guarantee the integrity of the printed green parts and of small-size structures during de-caking and the pick-up procedure.Furthermore,the casting made from the printed sand molds exhibits a relatively high quality.展开更多
In this study,C_(f)/SiC composites with excellent mechanical and thermal properties were prepared by combining binder jetting(BJ)additive manufacturing with liquid silicon infiltration(LSI)process.The introduction of ...In this study,C_(f)/SiC composites with excellent mechanical and thermal properties were prepared by combining binder jetting(BJ)additive manufacturing with liquid silicon infiltration(LSI)process.The introduction of C_(f)into the C_(f)/SiC mixed powder reduced its spreading ability,which reduced the density,strength,and precision of the C_(f)/SiC green parts.However,phenolic resin infiltration and pyrolysis(PRIP)treatment compensated for the decrease in the density of the green parts resulting from the introduction of C_(f).By optimizing the number of PRIP cycles to increase the pyrolytic carbon(PyC)content in the carbonized parts,the C_(f)in the green parts successfully prevented the reaction with molten Si in the LSI and played an important role in strengthening and toughening the composites.The flexural strength,fracture toughness,and thermal conductivity of the C_(f)/SiC composites reached the maximum values of 316±16 MPa,4.81±0.12 MPa·m^(1/2),and 140 W/m·K,respectively.This study presents future opportunities for the cost-effective and efficient industrial manufacturing of C_(f)/SiC complex structures.展开更多
Binder jet additive manufacturing is used for producing molds and cores for sand casting,by using granular material and proper binder.The conventional system uses a layer-by-layer gantry motion.The new continuous prin...Binder jet additive manufacturing is used for producing molds and cores for sand casting,by using granular material and proper binder.The conventional system uses a layer-by-layer gantry motion.The new continuous printing machine is a helical motion system.It includes a recoating blade for the granular material which has been investigated.This study focuses on analysing the behaviour of the recoating blade when it moves in a circular or the helical motion,as well as assessing the quality of the layer surface.Discrete Element Method(DEM)simulations was conducted using various blade geometry,and the results were compared with experimental models.The input parameters of the sand material were calibrated using a reverse calibration model,which iteratively adjusts the parameter values until they match the bulk response observed in real experiments.This research study employed experimental testing and DEM modeling,initially using a normal blade to produce an annular disc,and then optimizing the blade shape to achieve full disc printing.展开更多
Originally developed decades ago, the binder jetting additive manufacturing （B J-AM） process possesses various advantages compared to other additive manufacturing （AM） technologies such as broad material compat- i...Originally developed decades ago, the binder jetting additive manufacturing （B J-AM） process possesses various advantages compared to other additive manufacturing （AM） technologies such as broad material compat- ibility and technological expandability. However, the adoption of B J-AM has been limited by the lack of knowledge with the fundamental understanding of the process principles and characteristics, as well as the relatively few systematic design guideline that are available. In this work, the process design considerations for B J-AM in green part fabrication were discussed in detail in order to provide a comprehensive perspective of the design for additive manufacturing for the process. Various process factors, including binder saturation, in- process drying, powder spreading, powder feedstock characteristics, binder characteristics and post-process curing, could significantly affect the printing quality of the green parts such as geometrical accuracy and part integrity. For powder feedstock with low flowability, even though process parameters could be optimized to partially offset the printing feasibility issue, the qualities of the green parts will be intrinsically limited due to the existence of large internal voids that are inaccessible to the binder. In addition, during the process development, the balanced combination between the saturation level and in-process drying is of critical importance in the quality control of the green parts.展开更多
In response to the demand for environmentally friendly and sustainable manufacturing processes for intricate castings used in advanced equipment, binder jetting technology has emerged as a leading method for achieving...In response to the demand for environmentally friendly and sustainable manufacturing processes for intricate castings used in advanced equipment, binder jetting technology has emerged as a leading method for achieving rapid casting design and manufacturing. This technology has attracted much interest from research institutions, universities, and enterprises worldwide. Binder jetting-based sand-mold additive manufacturing can be used to manufacture complex sand molds (cores) directly and does not require traditional molds, expediting the produc- tion of complex castings and the accompanying process refinement. The exceptional design and manufacturing versatility afforded by this technology has enabled a profound transformation in the foundry industry, advancing the digitization, sustainability, and intelligent evolution of sand casting. This paper explores the recent research progress and achievements in the field of binder jetting sand-mold additive manufacturing in four dimensions: materials, design methods, process technologies, and system equipment. Finally, the characteristics and applica- tion advantages of binder jetting technology are analyzed, and the future development trends and challenges of binder jetting-based sand-mold additive manufacturing technology are investigated.展开更多
针对GH4099合金复杂构件对成形精度与服役性能的高要求,本工作开展了基于粘结剂喷射3D打印(binder jetting 3D printing,BJ3DP)的成形工艺优化与组织性能研究。通过正交试验分析层厚、粘结剂饱和度、铺粉速度及干燥时间对生坯表面质量...针对GH4099合金复杂构件对成形精度与服役性能的高要求,本工作开展了基于粘结剂喷射3D打印(binder jetting 3D printing,BJ3DP)的成形工艺优化与组织性能研究。通过正交试验分析层厚、粘结剂饱和度、铺粉速度及干燥时间对生坯表面质量的影响,明确粘结剂饱和度为主控因素,优化参数显著提升了成形均匀性与尺寸稳定性。进一步探究了烧结温度对组织与性能的调控作用,研究发现1345℃条件下相对密度达98.4%,组织致密,析出大量共格的L1_(2)型Ni_(3)(Al,Ti)相,在该条件下表现出了最佳的力学性能,抗拉强度和屈服强度分别为669和590 MPa。研究建立了BJ3DP成形参数与烧结制度协同调控GH4099组织-性能的作用机制,为实现高性能镍基合金复杂构件提供了新思路和理论支撑。展开更多
基金supported by the National Key R&D Pro-gram of China(No.2022YFB3805701)National Natural Science Foundation of China(NSFC)(No.52371182,51701052,52192592,52192593)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001)the Heilongjiang Touyan Innovation Team Program.
文摘1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.
基金the first Singapore-Germany Academic-Industry(2+2)international collaboration grant(Grant No.:A1890b0050)Agency for Science,Technology and Research(A^(*)STAR),under the RIE2020 Advanced Manufacturing and Engineering(AME)Programmatic Grant No.A1881b0061support of a scholarship from the A^(*)STAR Graduate Academy。
文摘Binder jet printing(BJP)is a state-of-the-art additive manufacturing technique for producing porous magnesium structures.Porous MgZn-Zr based BJP samples were assessed for corrosion performance in simulated body fluids by electrochemical and hydrogen evolution measurements.The corrosion rates of the BJP specimens were significantly higher than solid controls,even after accounting for their larger surface areas,suggesting that the BJP microstructure is detrimental to corrosion performance.X-ray computed tomography revealed nonuniform corrosion within the porous structure,with corrosion products forming on the pore walls.Impregnating the pores with hydroxyapatite or polymers greatly improved the corrosion resistance of the BJP samples.
文摘This study investigates full liquid phase sintering as a process of fabrication parts from WE43(Mg-4wt.%Y-3wt.%RE-0.7wt.%Zr)alloy using binder jetting additive manufacturing(BJAM).This fabrication process is being developed for use in producing structural or biomedical devices.Specifically,this study focused on achieving a near-dense microstructure with WE43 Mg alloy while substantially reducing the duration of sintering post-processing after BJAM part rendering.The optimal process resulted in microstructure with 2.5%porosity and significantly reduced sintering time.The improved sintering can be explained by the presence of Y_(2)O_(3)and Nd_(2)O_(3)oxide layers,which form spontaneously on the surface of WE43 powder used in BJAM.These layers appear to be crucial in preventing shape distortion of the resulting samples and in enabling the development of sintering necks,particularly under sintering conditions exceeding the liquidus temperature of WE43 alloy.Sintered WE43 specimens rendered by BJAM achieved significant improvement in both corrosion resistance and mechanical properties through reduced porosity levels related to the sintering time.
基金funding support from the Natural Sciences and Engineering Research Council of Canada(NSERC)the Canada Research Chairs(CRC)Program+1 种基金Huys Industries and the CWB Welding Foundationthe Centre for Advanced Materials Joining and the Multi-Scale Additive Manufacturing Lab at the University of Waterloo。
文摘Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal phases.However,the properties are highly dependent on the reinforcing phase composition,volume fraction and morphology.Continuous fiber or network reinforcement morphologies are difficult and expensive to manufacture,and the often-used discontinuous particle or whisker reinforcement morphologies result in less effective properties.Here,we demonstrate the formation of a co-continuous ceramic-reinforced metal matrix composite using solid-state processing.Binder jet additive manufacturing(BJAM)was used to print a nickel superalloy part followed by post-processing via reactive sintering to form a continuous carbide reinforcing phase at the particle boundaries.The kinetics of reinforcement formation are investigated in order to develop a relationship between reactive sintering time,temperature and powder composition on the reinforcing phase thickness and volume fraction.To evaluate performance,the wear resistance of the reinforced BJAM alloy 625 MMC was compared to unreinforced BJAM alloy 625,demonstrating a 64%decrease in the specific wear rate under abrasive wear conditions.
基金the National Key Research and Development Program of China(No.2018YFB1106800)。
文摘Binder jetting 3D printing is a rapid,cost effective,and efficient moulding/core making process,which can be applied to a large variety of materials.However,it exhibits a relatively low green-part strength.This may cause the collapse of the printed parts during de-caking and the pick-up procedure,especially in the case of small-scale structures,such as thin walls,tips,and channels.In this work,polyvinyl alcohol(PVA)was used as the additive in coated sand powder.By exploiting the binding effect between the two composites(thermoplastic phenolic resin and PVA)triggered by the binder,bonding necks firmly form among the sand particles,improving the green-part strength of the coated sand printed parts.Experiments based on the Taguchi method were used to investigate the relationship between the process parameters and the green-part tensile strength.The following set of optimal process parameters was identified:50wt.%alcoholicity of the binder,75%binder saturation,0.36 mm layer thickness and 4.5wt.%PVA content.Further,the effect of such parameters on the green-part tensile strength was determined via statistical analysis.The green part of an engine cylinder head sand pattern with complex cavity structures was printed,and the green-part tensile strength reached 2.31 MPa.Moreover,the ZL301 aluminum alloy impeller shape casting was prepared using sand molds printed with the optimal process parameters.The results confirm that the proposed binder jetting 3D printing process can guarantee the integrity of the printed green parts and of small-size structures during de-caking and the pick-up procedure.Furthermore,the casting made from the printed sand molds exhibits a relatively high quality.
基金supported by National Defense Basic Scientific Research Program of China(Grant No.JCKY2022213C008)Fundamental Research Funds for the Central Universities of China(Grant No.YCJJ20230353)。
文摘In this study,C_(f)/SiC composites with excellent mechanical and thermal properties were prepared by combining binder jetting(BJ)additive manufacturing with liquid silicon infiltration(LSI)process.The introduction of C_(f)into the C_(f)/SiC mixed powder reduced its spreading ability,which reduced the density,strength,and precision of the C_(f)/SiC green parts.However,phenolic resin infiltration and pyrolysis(PRIP)treatment compensated for the decrease in the density of the green parts resulting from the introduction of C_(f).By optimizing the number of PRIP cycles to increase the pyrolytic carbon(PyC)content in the carbonized parts,the C_(f)in the green parts successfully prevented the reaction with molten Si in the LSI and played an important role in strengthening and toughening the composites.The flexural strength,fracture toughness,and thermal conductivity of the C_(f)/SiC composites reached the maximum values of 316±16 MPa,4.81±0.12 MPa·m^(1/2),and 140 W/m·K,respectively.This study presents future opportunities for the cost-effective and efficient industrial manufacturing of C_(f)/SiC complex structures.
文摘Binder jet additive manufacturing is used for producing molds and cores for sand casting,by using granular material and proper binder.The conventional system uses a layer-by-layer gantry motion.The new continuous printing machine is a helical motion system.It includes a recoating blade for the granular material which has been investigated.This study focuses on analysing the behaviour of the recoating blade when it moves in a circular or the helical motion,as well as assessing the quality of the layer surface.Discrete Element Method(DEM)simulations was conducted using various blade geometry,and the results were compared with experimental models.The input parameters of the sand material were calibrated using a reverse calibration model,which iteratively adjusts the parameter values until they match the bulk response observed in real experiments.This research study employed experimental testing and DEM modeling,initially using a normal blade to produce an annular disc,and then optimizing the blade shape to achieve full disc printing.
基金Acknowledgements The authors would like to acknowledge the support of Rapid Prototyping Center （RPC） at University of Louisville and the many technical insights and discussions from Dan Brunermer at ExOne LLC. This work was partially supported by National Science Foundation （Grant No. 1450370, subaward No. OGMN 131508E4）.
文摘Originally developed decades ago, the binder jetting additive manufacturing （B J-AM） process possesses various advantages compared to other additive manufacturing （AM） technologies such as broad material compat- ibility and technological expandability. However, the adoption of B J-AM has been limited by the lack of knowledge with the fundamental understanding of the process principles and characteristics, as well as the relatively few systematic design guideline that are available. In this work, the process design considerations for B J-AM in green part fabrication were discussed in detail in order to provide a comprehensive perspective of the design for additive manufacturing for the process. Various process factors, including binder saturation, in- process drying, powder spreading, powder feedstock characteristics, binder characteristics and post-process curing, could significantly affect the printing quality of the green parts such as geometrical accuracy and part integrity. For powder feedstock with low flowability, even though process parameters could be optimized to partially offset the printing feasibility issue, the qualities of the green parts will be intrinsically limited due to the existence of large internal voids that are inaccessible to the binder. In addition, during the process development, the balanced combination between the saturation level and in-process drying is of critical importance in the quality control of the green parts.
基金supported by National Key R&D Program of China(Grant No.2021YFB3401200)Jiangsu Provincial Basic Research Pro-gram(Natural Science Foundation)Youth Fund of China(Grant No.BK20230885)the Special Technical Project for Equipment Pre-research(Grant No.30104040302).
文摘In response to the demand for environmentally friendly and sustainable manufacturing processes for intricate castings used in advanced equipment, binder jetting technology has emerged as a leading method for achieving rapid casting design and manufacturing. This technology has attracted much interest from research institutions, universities, and enterprises worldwide. Binder jetting-based sand-mold additive manufacturing can be used to manufacture complex sand molds (cores) directly and does not require traditional molds, expediting the produc- tion of complex castings and the accompanying process refinement. The exceptional design and manufacturing versatility afforded by this technology has enabled a profound transformation in the foundry industry, advancing the digitization, sustainability, and intelligent evolution of sand casting. This paper explores the recent research progress and achievements in the field of binder jetting sand-mold additive manufacturing in four dimensions: materials, design methods, process technologies, and system equipment. Finally, the characteristics and applica- tion advantages of binder jetting technology are analyzed, and the future development trends and challenges of binder jetting-based sand-mold additive manufacturing technology are investigated.
文摘针对GH4099合金复杂构件对成形精度与服役性能的高要求,本工作开展了基于粘结剂喷射3D打印(binder jetting 3D printing,BJ3DP)的成形工艺优化与组织性能研究。通过正交试验分析层厚、粘结剂饱和度、铺粉速度及干燥时间对生坯表面质量的影响,明确粘结剂饱和度为主控因素,优化参数显著提升了成形均匀性与尺寸稳定性。进一步探究了烧结温度对组织与性能的调控作用,研究发现1345℃条件下相对密度达98.4%,组织致密,析出大量共格的L1_(2)型Ni_(3)(Al,Ti)相,在该条件下表现出了最佳的力学性能,抗拉强度和屈服强度分别为669和590 MPa。研究建立了BJ3DP成形参数与烧结制度协同调控GH4099组织-性能的作用机制,为实现高性能镍基合金复杂构件提供了新思路和理论支撑。
