MXenes are emerging transition metal carbides and nitrides-based 2D conductive materials.They have found wide applications in sensors due to their excellent valuable properties.This paper reviews the recent research s...MXenes are emerging transition metal carbides and nitrides-based 2D conductive materials.They have found wide applications in sensors due to their excellent valuable properties.This paper reviews the recent research status of MXene-based electrochemical(bio)sensors for detecting biomarkers,pesticides,and other aspects.The first part of this paper introduced the synthesis strategy and the effect of surface modification on various prop-erties of MXenes.The second part of this paper discussed the application of MXenes as electrode modifiers for detecting pesticides,environmental pollutants,and biomarkers such as glucose,hydrogen peroxide,etc.Hope this review will inspire more efforts toward research on MXene-based sensors to meet the growing requirements.展开更多
Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance b...Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.展开更多
Magnesium(Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal body.In addition to biodegradability,their inherent biocompatibility and similar-to-b...Magnesium(Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal body.In addition to biodegradability,their inherent biocompatibility and similar-to-bone density make Mg-based alloys good candidates for fabricating surgical bioimplants for use in orthopedic and traumatology treatments.To this end,nowadays additive manufacturing(AM)along with three-dimensional(3D)printing represents a promising manufacturing technique as it allows for the integration of bioimplant design and manufacturing processes specific to given applications.Meanwhile,this technique also faces many new challenges associated with the properties of Mg-based alloys,including high chemical reactivity,potential for combustion,and low vaporization temperature.In this review article,various AM processes to fabricate biomedical implants from Mg-based alloys,along with their metallic microstructure,mechanical properties,biodegradability,biocompatibility,and antibacterial properties,as well as various post-AM treatments were critically reviewed.Also,the challenges and issues involved in AM processes from the perspectives of bioimplant design,properties,and applications were identified;the possibilities and potential scope of the Mg-based scaffolds/implants are discussed and highlighted.展开更多
Biocomposites as bio-inspired materials are produced from renewable resources that are organic and ecofriendly alternative materials.To improve the lifestyle of human beings as well as enhancing the environmental indi...Biocomposites as bio-inspired materials are produced from renewable resources that are organic and ecofriendly alternative materials.To improve the lifestyle of human beings as well as enhancing the environmental indices,functional bio-materials are now implemented in various promising industries.This work has systematically discussed and highlighted the implementations and trends of functional bionic materials in high tech industries,which are necessary for developing modern societies.Various medical,electronic,food and pharmaceutical applications have been considered.Bio-inspired materials are used to develop more sustainable possibilities to increase environmental conservation while maintaining customer satisfaction.Biopolymers were found employed in several sectors for various functional bio-products including organic thin-film transistors,organic phototransistor,emitting diodes,photodiodes,photovoltaic solar cells,hybrid dental resins,sustainable pharmaceuticals,and food packaging.They are used to create sustainable bio-products for energy storage and harvesting,bone regeneration,nerve damage repair,drug applications and various other industrial subcategories.展开更多
Coronaviruses are responsible for a developing budgetary,human and fatality trouble,as the causative factor of infections,for example,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).It has been well recogn...Coronaviruses are responsible for a developing budgetary,human and fatality trouble,as the causative factor of infections,for example,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).It has been well recognized that SARS-CoV-2 may survive under severe atmosphere circumstances.Hence,efficient containment approaches,for example,sanitizing,are crucial.Commonly,living compounds contribute a substance of chemical heterogeneity,with antiviral movement,and therefore can have efficacy as therapeutic tools toward coronavirus diseases.Here,in this review article,we have described the antimicrobialbased materials,which can be used to inhibit the spreading of the COVID-19.We have categorized these materials in three sections;(i)antimicrobial wall paint,(ii)antimicrobial papers and(iii)antimicrobial materials surface coating to be utilized as the antimicrobial-based materials for controlling the COVID-19.In the last section,we have given the concluding remarks with prospects in this area.展开更多
The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechan...The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechanical properties and related strengthening mechanisms has not been fully elucidated.Herein,under the same volume fraction and distribution conditions of graphene,molecular dynamics simulations were used to investigate the effect of graphene sheet size on the hardness and deformation behavior of Cu/graphene composites under complex stress field.Two models of pure single crystalline Cu and graphene fully covered Cu matrix composite were constructed for comparison.The results show that the strengthening effect changes with varying the graphene sheet size.Besides the graphene dislocation blocking effect and the load-bearing effect,the deformation mechanisms change from stacking fault tetrahedron,dislocation bypassing and dislocation cutting to dislocation nucleation in turn with decreasing the graphene sheet size.The hardness of Cu/graphene composite,with the graphene sheet not completely covering the metal matrix,can even be higher than that of the fully covered composite.The extra strengthening mechanisms of dislocation bypassing mechanism and the stacking fault tetrahedra pinning dislocation mechanism contribute to the increase in hardness.展开更多
In the current study the wear behavior of the ZK60/SiC composites reinforced by particles and whiskers in both as-cast and extruded conditions was examined.Furthermore,the wear behavior of the extruded samples along t...In the current study the wear behavior of the ZK60/SiC composites reinforced by particles and whiskers in both as-cast and extruded conditions was examined.Furthermore,the wear behavior of the extruded samples along the extrusion direction and perpendicular to the extrusion direction was studied.The wear tests were performed at temperatures of 100,200,and 300℃under loads of 10,20,and 30 N.The results showed that the whisker-reinforced sample(5.8×10^(–4)g/[N.m])had higher wear resistance than the particle-reinforced sample(1.3×10^(–3)g/[N.m]).The lowest wear rate was observed for the extruded sample in the extrusion direction(3.53×10^(–4)g/[N.m]).It was also found that the wear rate increased by∼20%with increasing temperature,but in the ZK60/SiC_(w)sample,dynamic precipitation increased the wear resistance.The coefficient of friction was also found to increase with rising temperature,showing an increase of approximately 12.5%at a 10 N load and 20%at a 30 N load.Examination of the worn surfaces by scanning electron microscopy showed that the as-cast ZK60 alloy at 100℃had the oxidative-abrasive as the dominant mechanism.It was found that by extruding the sample,the strength of the sample increased and the mechanism changed to adhesive wear.In the ZK60/SiC_(p)composite,the viscoplastic wear mechanism was dominant.Although in the extruded sample the dominant mechanism changed to plastic deformation.As temperature increases,the viscoplastic wear mechanism became dominant again.In the as-cast ZK60/SiC_(w)composite,the abrasive wear mechanism changed to delamination with increasing temperature.By extruding the sample,the dominant mechanism changed to adhesive wear.Finally,dynamic precipitation induced by temperature caused an increase in the wear resistance.展开更多
Mimicking the hierarchical structure of the skin is one of the most important strategies in skin tissue engineering.Monolayer wound dressings are usually not able to provide several functions at the same time and cann...Mimicking the hierarchical structure of the skin is one of the most important strategies in skin tissue engineering.Monolayer wound dressings are usually not able to provide several functions at the same time and cannot meet all clinical needs.In order to maximize therapeutic efficiency,herein,we fabricated a Tri-layer wound dressing,where the middle layer was fabricated via 3D-printing and composed of alginate,tragacanth and zinc oxide nanoparticles(ZnO NPs).Both upper and bottom layers were constructed using electrospinning technique;the upper layer was made of hydrophobic polycaprolactone to mimic epidermis,while the bottom layer consisted of Soluplus■ and insulin-like growth factor-1(IGF-1)to promote cell behavior.Swelling,water vapor permeability and tensile properties of the dressings were evaluated and the Tri-layer dressing exhibited impressive antibacterial activity and cell stimulation following by the release of ZnO NPs and IGF-1.Additionally,the Tri-layer dressing led to faster healing of full-thicknesswound in ratmodel compared to monolayer and Bilayer dressings.Overall,the evidence confirmed that the Trilayer wound dressing is extremely effective for full-thickness wound healing.展开更多
Friction stir processing(FSP)induces severe plastic deformation,generating intense strains and localized heating,which modifies the surface and enables the fabrication of magnesium(Mg)-based composites.This technique ...Friction stir processing(FSP)induces severe plastic deformation,generating intense strains and localized heating,which modifies the surface and enables the fabrication of magnesium(Mg)-based composites.This technique refines the microstructure of Mg alloys,enhancing mechanical properties—particularly ductility,a key limitation of these HCP alloys.This review addresses the underlying microstructural evolution during FSP of Mg alloys and Mg-matrix composites,including(i)grain refinement via continuous and discontinuous dynamic recrystallization(CDRX and DDRX),(ii)fragmentation and redistribution of secondary phases and intermetallics,(iii)transformation of low-and high-angle grain boundaries,and(iv)additional microstructural changes induced by external reinforcements.This review provides a comprehensive analysis of the strengthening mechanisms and their impact on the mechanical properties of FSP Mg alloys and Mgmatrix composites(MMCs).The paper examines the correlation between FSP processing parameters,microstructural evolution,and resulting mechanical properties.It critically highlights how the type of reinforcement and the dynamic recrystallization induced by friction stir processing influence grain boundary character and,consequently,the material’s strengthening response.It includes a comparative evaluation of yield stress,ultimate tensile strength,microhardness,elongation,and fractography for various FSP-treated Mg alloys and MMCs,including AZxx,WExx,ZExx,ZKxx,AMxx,AExx,and Mg-rare earth alloys.Additionally,the novelty of this review lies in its emphasis on connecting microstructural transformations to mechanical performance trends across different alloy systems and processing strategies,an aspect that has been underexplored in previous reviews.Recent advancements in FSP techniques and their implications for improving the performance of Mg-based materials are also discussed.展开更多
The research of rare earths for the synthesis of materials with improved mechanical performance is of great interest when they are considered for potential applications in the automotive industry. In this regard, the ...The research of rare earths for the synthesis of materials with improved mechanical performance is of great interest when they are considered for potential applications in the automotive industry. In this regard, the effect on the mechanical properties and microstmcture of the automotive A356 aluminum alloy reinforced with 0.2 （wt.%） AI-6Ce-3La （ACL） was investigated. The ACL was added to the melted A356 alloy in the as-received condition and processed by mechanical milling. In the second route, the effect of the ACL processed by mechanical milling and powder metallurgy techniques was investigated, and compared with the results ob- tained from the A356 alloy strengthened with ACL in the as-received condition. Microstmctural properties were evaluated by means of X-ray diffraction in order to observe the solubility of Ce/La in the A1 matrix. In addition, electron microscopy was employed in or- der to investigate the effect of milling time on the size and morphology of La/Ce phase under milling process. Mechanical properties of the A356 alloy modified with ACL were measured by hardness and tensile test. For comparison unmodified specimens of the A356 were characterized according to the previous procedure. The microstructural and mechanical characterization was carried out in specimens alter solution and artificial aging. Observations in scanning electron microscopy indicated a homogeneous dispersion of La/Ce phases by using both routes; however, mechanical results, in the modified A356 alloy with the ACL in the as-received condi- tion, showed an improvement in the mechanical performance of the A356 alloy over that reinforced with the ACL mechanically milled.展开更多
The dissimilar joining of biodegradable magnesium alloy to pure commercial titanium by rotational friction welding with rotational speeds of 1100,1200 and 1300 r/min for the production of bio-screw was investigated.Th...The dissimilar joining of biodegradable magnesium alloy to pure commercial titanium by rotational friction welding with rotational speeds of 1100,1200 and 1300 r/min for the production of bio-screw was investigated.The metallographic analysis revealed that a good joining was obtained at the Ti/Mg alloy joint.On the magnesium alloy side,various regions such as the weld center zone(WCZ),dynamic recrystallization zone(DRX),thermo-mechanically affected zone(TMAZ)and partially deformed zone(PDZ)were observed.The highest tensile and shear strengths were 173 and 103.2 MPa,respectively at a rotational speed of 1300 r/min.The Ti/Mg alloy dissimilar friction welded joint failed at the vicinity of the intermetallic zone containing Ti3Al phase.The hardness values from the base metal magnesium alloy to the joining point increased mainly due to grain refinement(8.57μm in diameter)and the presence of titanium particles,while the hardness values were constant on the titanium side.It was also found that the corrosion rate of the Ti/Mg alloy joint was higher compared with that of the Ti and Mg alloy from the immersion studies.Additionally,the sample with a rotational speed of 1300 r/min showed better biocompatibility and a cell viability of 98.12%due to better corrosion resistance.展开更多
The microstructure and mechanical properties of 105 mm thick 5083 aluminum alloy hot rolled plate were investigated by metallurgical microscope, scanning electron microscope and tensile testing machine, and three majo...The microstructure and mechanical properties of 105 mm thick 5083 aluminum alloy hot rolled plate were investigated by metallurgical microscope, scanning electron microscope and tensile testing machine, and three major characteristic problems in mechanical properties inhomogeneity were explained. The results show that the mechanical properties of the rolled plate are inhomogeneous along the thickness direction. From the surface to the center, the strength shows an inverted "N" shape change and the elongation presents a semi "U" shape change. Several similar structural units composed of long fibrous grains(LFG) and short fibrous grains bands(SFGB) exist in a special layer(Layer 2) adjacent to the surface. This alternating layered distribution of LFG and SFGB is conducive to improving the plasticity by dispersing the plastic deformation concentrated on the boundary line(BL) between them. However, their different deformability will cause the alternation of additional stresses during the hot rolling, leading to the strength reduction. The closer the location to the center of the plate is, the more likely the recovery rather than the recrystallization occurs. This is the possible reason for the unnegligible difference in strength near the central region(Layer 4 and Layer 5).展开更多
Magnetic properties of diluted magnetic semiconductors (DMSs), Ni-doped ZnO materials, prepared by sol-gel method were investigated by measuring magnetization as functions of magnetic field. The Ni content affects the...Magnetic properties of diluted magnetic semiconductors (DMSs), Ni-doped ZnO materials, prepared by sol-gel method were investigated by measuring magnetization as functions of magnetic field. The Ni content affects the magnetic properties at low sintered temperature but it has few effects on the magnetic properties at high sintered temperature. The sintered temperature has great effects on the magnetic properties of Ni/ZnO at high original mole ratio of Ni/Zn while it has slight effects on the magnetic properties of Ni/ZnO at low original mole ratio of Ni/Zn whatever low or high sintered temperature.展开更多
The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded...The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded Mg–9Li–1Al–xCa alloys were observed to investigate the effect of calcium(Ca)element on the Mg–9Li–1Al(LA91)alloy,and the crystallographic calculations between Al_(2)Ca and the matrix(α-Mg andβ-Li phases)were examined on the basis of the edge-to-edge matching model.The experimental results indicate that the addition of 0.2 wt%Ca into LA91 alloy reduce the size of theα-Mg phases in the as-cast alloy and that ofβ-Li phases in the as-extruded alloy due to the Al_(2)Ca particles distributed inside the matrix.Crystallographic calculation results suggested that there is a good crystallographic matching between the matrix and Al_(2)Ca,which confirmed that Al_(2)Ca particles can act as a heterogeneous nucleation site for bothα-Mg andβ-Li phases and were effective grain refiners for LA91 alloy.展开更多
The effects of the rare earth element Y addition on mechanical properties and energy absorption of a low Zn content Mg-Zn-Zr system alloy and the deformation temperature of optimized alloy were investigated by room te...The effects of the rare earth element Y addition on mechanical properties and energy absorption of a low Zn content Mg-Zn-Zr system alloy and the deformation temperature of optimized alloy were investigated by room tensile test, optical microscopy （OM）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscope （TEM）. The results show that, after homogenization at 420℃ for 12 h for the as-cast alloys, MgZn phase forms, which decreases the strength of Mg-2.0Zn-0.3Zr alloy with Y content of 0.9 wt%. The tensile strength and elongation of the alloy with a Y addition of 5.8 wt% reach the max value （281 ±2） MPa and （30.1 ± 0.7） %, respectively; the strength and elongation of Mg-2.0Zn-0.3Zr-0.9Y alloy at the optimized extrusion temperature of 330 ℃ reach （321 ± 1） MPa and （21.9 ± 0.7） %, respectively. The energy absorption increases with the increase of Y content, the max value reached 0.79 MJ·m^-3 with Y content of 5.8 wt%, and the energy absorption of Mg-2.0Zn-0.3Zr-0.9Y alloy at the optimized extrusion temperature of 330 ℃ reaches 0.75 MJ·m^-3.展开更多
A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoat...A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoated samples were assessed.Mechanical alloying followed by sintering was applied to fabricate the Mg–3Zn–0.5Ag–15NiTi nanocomposite substrate.Moreover, different contents of poly(lactic-co-glycolic acid)(PLGA) coatings were studied, and 10 wt% of PLGA content was selected.The scanning electron microscopy(SEM) images of the bulk nanocomposite showed an acceptable homogenous dispersion of the Ni Ti nanoparticles(NPs) in the Mg-based matrix.In the in vitro bioactivity evaluation, following the immersion of the uncoated and coated samples in a simulated body fluid(SBF) solution, the Ca/P atomic ratio demonstrated that the apatite formation amount on the coated sample was greater than that on the uncoated nanocomposite.Furthermore, assessing the corrosion resistance indicated that the coatings on the Mg-based substrate led to a corrosion current density(icorr) that was considerably lower than that of the substrate.Such a condition revealed that the coating would provide an obstacle for the corrosion.Based on this study, the PLGA/hardystonite(HT) composite-coated Mg–3Zn–0.5Ag–15NiTi nanocomposite may be suitably applied as an orthopedic implant biomaterial.展开更多
Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is sti...Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.展开更多
An investigation was carried out to assess the applicability of transient liquid phase bonding of two dissimilar super-alloys with different interlayers. The effect of using three types of interlayer such as BNi-2, BN...An investigation was carried out to assess the applicability of transient liquid phase bonding of two dissimilar super-alloys with different interlayers. The effect of using three types of interlayer such as BNi-2, BNi-3, and BNi-9 on microstructure and mechanical properties was studied in the GTD-111/IN-718 system at 1100 ℃ for different bonding time. To determine the compositional changes and microstructure in the joint region, field emission scanning electron microscopy equipped with energy dispersive spectroscopy was utilized. The formation of Ni_(3)B in the athermally solidified zone(ASZ) is controlled by the B content and, accordingly, the morphology of Ni_(3)Si is governed by the Si content. The Cr content might impede the relocation of B from the interlayer into the base metal and the formation of CrB inside the ASZ is dominated by the Cr content. The high micro-hardness of the eutectic compounds is originated from the formation of boride matrixes such as Ni or Cr boride. The shear strength of the joint using BNi-9 after the completion of isothermal solidification is lower compared that that using BNi-3 and BNi-2, which could be related to the absence of Si in the filler metals constituent and the significant presence of Cr in BNi-9.展开更多
The aim of this study was to evaluate the strain hardening and hot deformation behavior of asextruded Mg-Zn-Mn （ZM31） magnesium alloy with varying Y contents （0.3, 3.2, and 6 wt%） via compression testing along the...The aim of this study was to evaluate the strain hardening and hot deformation behavior of asextruded Mg-Zn-Mn （ZM31） magnesium alloy with varying Y contents （0.3, 3.2, and 6 wt%） via compression testing along the extrusion direction at room temperature, 200℃ and 300 ℃. Texture and phases were identified by X-ray diffraction. Alloy ZM31 ＋ 0.3Y consisted of a mixture of fine equiaxed grains and elon- gated grains with 1-phase （Mg3YZno）; alloy ZM31 ＋ 3.2Y contained 1-phase and W-phase （Mg3Y2Zn3）; alloy ZM31 ＋ 6Y had long-period stacking-ordered （LPSO） X-phase （Mg12YZn） and Mg24Y5 particles. With increasing Y content the basal texture became weakened significantly. While alloys ZM31 ＋ 0.3Y and ZM31 ＋ 3.2Y exhibited a skewed true stress-true stain curve with a three-stage strain hardening feature caused by the occurrence of {1072} extension twinning, the true stress-true stain curve of alloy ZM31 ＋ 6Y was normal due to the dislocation slip during compression. With increasing temperature the extent of skewness decreased. While the compressive yield stress, ultimate compressive stress, strain hardening exponent, and hardening capacity all decreased as the temperature increased, the retention of the high- temperature deformation resistance increased with increasing Y content mainly due to the presence of thermally-stable LPSO X-ohase.展开更多
Mg alloys have been widely used in automobile and electronic industries because of high specific strength, good castability, etc. However, molten Mg alloys will burn rapidly in air if not protected. To solve this prob...Mg alloys have been widely used in automobile and electronic industries because of high specific strength, good castability, etc. However, molten Mg alloys will burn rapidly in air if not protected. To solve this problem, the molten metal should be protected from oxidation by blanketing the surface with flux or protective gases. SF6 gas is widely used for Mg alloys as a cover gas and has proved to be a successful inhibitor. However, the use of SF6 gas is limited because of its high cost and its significant impact on non-global warming potential. Therefore, SF6 gas is being replaced by alternative protection gases. Recent studies show that there has been another attempt by adding CaO into Mg alloys. The aim of this study is to evaluate the effect of CaO on the minimum amount of protective gas, which is necessary not to make ignition in the molten AZ31 and AZ91 Mg alloys.展开更多
文摘MXenes are emerging transition metal carbides and nitrides-based 2D conductive materials.They have found wide applications in sensors due to their excellent valuable properties.This paper reviews the recent research status of MXene-based electrochemical(bio)sensors for detecting biomarkers,pesticides,and other aspects.The first part of this paper introduced the synthesis strategy and the effect of surface modification on various prop-erties of MXenes.The second part of this paper discussed the application of MXenes as electrode modifiers for detecting pesticides,environmental pollutants,and biomarkers such as glucose,hydrogen peroxide,etc.Hope this review will inspire more efforts toward research on MXene-based sensors to meet the growing requirements.
基金supported by the Agency for Defense Development Grant Funded by the Korean Government(Grant No.912822501).
文摘Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.
文摘Magnesium(Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal body.In addition to biodegradability,their inherent biocompatibility and similar-to-bone density make Mg-based alloys good candidates for fabricating surgical bioimplants for use in orthopedic and traumatology treatments.To this end,nowadays additive manufacturing(AM)along with three-dimensional(3D)printing represents a promising manufacturing technique as it allows for the integration of bioimplant design and manufacturing processes specific to given applications.Meanwhile,this technique also faces many new challenges associated with the properties of Mg-based alloys,including high chemical reactivity,potential for combustion,and low vaporization temperature.In this review article,various AM processes to fabricate biomedical implants from Mg-based alloys,along with their metallic microstructure,mechanical properties,biodegradability,biocompatibility,and antibacterial properties,as well as various post-AM treatments were critically reviewed.Also,the challenges and issues involved in AM processes from the perspectives of bioimplant design,properties,and applications were identified;the possibilities and potential scope of the Mg-based scaffolds/implants are discussed and highlighted.
文摘Biocomposites as bio-inspired materials are produced from renewable resources that are organic and ecofriendly alternative materials.To improve the lifestyle of human beings as well as enhancing the environmental indices,functional bio-materials are now implemented in various promising industries.This work has systematically discussed and highlighted the implementations and trends of functional bionic materials in high tech industries,which are necessary for developing modern societies.Various medical,electronic,food and pharmaceutical applications have been considered.Bio-inspired materials are used to develop more sustainable possibilities to increase environmental conservation while maintaining customer satisfaction.Biopolymers were found employed in several sectors for various functional bio-products including organic thin-film transistors,organic phototransistor,emitting diodes,photodiodes,photovoltaic solar cells,hybrid dental resins,sustainable pharmaceuticals,and food packaging.They are used to create sustainable bio-products for energy storage and harvesting,bone regeneration,nerve damage repair,drug applications and various other industrial subcategories.
基金This investigation work was financially supported by the National Natural Science Foundation of China(21962008,51464028)Candidate Talents Training Fund of Yunnan Province(2017PY269SQ,2018HB007)Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWR-QNBJ-2018-346).
文摘Coronaviruses are responsible for a developing budgetary,human and fatality trouble,as the causative factor of infections,for example,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).It has been well recognized that SARS-CoV-2 may survive under severe atmosphere circumstances.Hence,efficient containment approaches,for example,sanitizing,are crucial.Commonly,living compounds contribute a substance of chemical heterogeneity,with antiviral movement,and therefore can have efficacy as therapeutic tools toward coronavirus diseases.Here,in this review article,we have described the antimicrobialbased materials,which can be used to inhibit the spreading of the COVID-19.We have categorized these materials in three sections;(i)antimicrobial wall paint,(ii)antimicrobial papers and(iii)antimicrobial materials surface coating to be utilized as the antimicrobial-based materials for controlling the COVID-19.In the last section,we have given the concluding remarks with prospects in this area.
基金Foundation of Northwest Institute for Nonferrous Metal Research(ZZXJ2203)Capital Projects of Financial Department of Shaanxi Province(YK22C-12)+3 种基金Innovation Capability Support Plan in Shaanxi Province(2023KJXX-083)Key Research and Development Projects of Shaanxi Province(2024GXYBXM-351,2024GX-YBXM-356)National Natural Science Foundation of China(62204207,12204383)Xi'an Postdoctoral Innovation Base Funding Program。
文摘The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechanical properties and related strengthening mechanisms has not been fully elucidated.Herein,under the same volume fraction and distribution conditions of graphene,molecular dynamics simulations were used to investigate the effect of graphene sheet size on the hardness and deformation behavior of Cu/graphene composites under complex stress field.Two models of pure single crystalline Cu and graphene fully covered Cu matrix composite were constructed for comparison.The results show that the strengthening effect changes with varying the graphene sheet size.Besides the graphene dislocation blocking effect and the load-bearing effect,the deformation mechanisms change from stacking fault tetrahedron,dislocation bypassing and dislocation cutting to dislocation nucleation in turn with decreasing the graphene sheet size.The hardness of Cu/graphene composite,with the graphene sheet not completely covering the metal matrix,can even be higher than that of the fully covered composite.The extra strengthening mechanisms of dislocation bypassing mechanism and the stacking fault tetrahedra pinning dislocation mechanism contribute to the increase in hardness.
文摘In the current study the wear behavior of the ZK60/SiC composites reinforced by particles and whiskers in both as-cast and extruded conditions was examined.Furthermore,the wear behavior of the extruded samples along the extrusion direction and perpendicular to the extrusion direction was studied.The wear tests were performed at temperatures of 100,200,and 300℃under loads of 10,20,and 30 N.The results showed that the whisker-reinforced sample(5.8×10^(–4)g/[N.m])had higher wear resistance than the particle-reinforced sample(1.3×10^(–3)g/[N.m]).The lowest wear rate was observed for the extruded sample in the extrusion direction(3.53×10^(–4)g/[N.m]).It was also found that the wear rate increased by∼20%with increasing temperature,but in the ZK60/SiC_(w)sample,dynamic precipitation increased the wear resistance.The coefficient of friction was also found to increase with rising temperature,showing an increase of approximately 12.5%at a 10 N load and 20%at a 30 N load.Examination of the worn surfaces by scanning electron microscopy showed that the as-cast ZK60 alloy at 100℃had the oxidative-abrasive as the dominant mechanism.It was found that by extruding the sample,the strength of the sample increased and the mechanism changed to adhesive wear.In the ZK60/SiC_(p)composite,the viscoplastic wear mechanism was dominant.Although in the extruded sample the dominant mechanism changed to plastic deformation.As temperature increases,the viscoplastic wear mechanism became dominant again.In the as-cast ZK60/SiC_(w)composite,the abrasive wear mechanism changed to delamination with increasing temperature.By extruding the sample,the dominant mechanism changed to adhesive wear.Finally,dynamic precipitation induced by temperature caused an increase in the wear resistance.
基金support of Isfahan University of Medical Sciences(Project code No.#1401262).
文摘Mimicking the hierarchical structure of the skin is one of the most important strategies in skin tissue engineering.Monolayer wound dressings are usually not able to provide several functions at the same time and cannot meet all clinical needs.In order to maximize therapeutic efficiency,herein,we fabricated a Tri-layer wound dressing,where the middle layer was fabricated via 3D-printing and composed of alginate,tragacanth and zinc oxide nanoparticles(ZnO NPs).Both upper and bottom layers were constructed using electrospinning technique;the upper layer was made of hydrophobic polycaprolactone to mimic epidermis,while the bottom layer consisted of Soluplus■ and insulin-like growth factor-1(IGF-1)to promote cell behavior.Swelling,water vapor permeability and tensile properties of the dressings were evaluated and the Tri-layer dressing exhibited impressive antibacterial activity and cell stimulation following by the release of ZnO NPs and IGF-1.Additionally,the Tri-layer dressing led to faster healing of full-thicknesswound in ratmodel compared to monolayer and Bilayer dressings.Overall,the evidence confirmed that the Trilayer wound dressing is extremely effective for full-thickness wound healing.
基金the National Science Foundation under grant number CMMI-2339857.
文摘Friction stir processing(FSP)induces severe plastic deformation,generating intense strains and localized heating,which modifies the surface and enables the fabrication of magnesium(Mg)-based composites.This technique refines the microstructure of Mg alloys,enhancing mechanical properties—particularly ductility,a key limitation of these HCP alloys.This review addresses the underlying microstructural evolution during FSP of Mg alloys and Mg-matrix composites,including(i)grain refinement via continuous and discontinuous dynamic recrystallization(CDRX and DDRX),(ii)fragmentation and redistribution of secondary phases and intermetallics,(iii)transformation of low-and high-angle grain boundaries,and(iv)additional microstructural changes induced by external reinforcements.This review provides a comprehensive analysis of the strengthening mechanisms and their impact on the mechanical properties of FSP Mg alloys and Mgmatrix composites(MMCs).The paper examines the correlation between FSP processing parameters,microstructural evolution,and resulting mechanical properties.It critically highlights how the type of reinforcement and the dynamic recrystallization induced by friction stir processing influence grain boundary character and,consequently,the material’s strengthening response.It includes a comparative evaluation of yield stress,ultimate tensile strength,microhardness,elongation,and fractography for various FSP-treated Mg alloys and MMCs,including AZxx,WExx,ZExx,ZKxx,AMxx,AExx,and Mg-rare earth alloys.Additionally,the novelty of this review lies in its emphasis on connecting microstructural transformations to mechanical performance trends across different alloy systems and processing strategies,an aspect that has been underexplored in previous reviews.Recent advancements in FSP techniques and their implications for improving the performance of Mg-based materials are also discussed.
基金support from CONACYT via PhD scholarship 290674 and 290604
文摘The research of rare earths for the synthesis of materials with improved mechanical performance is of great interest when they are considered for potential applications in the automotive industry. In this regard, the effect on the mechanical properties and microstmcture of the automotive A356 aluminum alloy reinforced with 0.2 （wt.%） AI-6Ce-3La （ACL） was investigated. The ACL was added to the melted A356 alloy in the as-received condition and processed by mechanical milling. In the second route, the effect of the ACL processed by mechanical milling and powder metallurgy techniques was investigated, and compared with the results ob- tained from the A356 alloy strengthened with ACL in the as-received condition. Microstmctural properties were evaluated by means of X-ray diffraction in order to observe the solubility of Ce/La in the A1 matrix. In addition, electron microscopy was employed in or- der to investigate the effect of milling time on the size and morphology of La/Ce phase under milling process. Mechanical properties of the A356 alloy modified with ACL were measured by hardness and tensile test. For comparison unmodified specimens of the A356 were characterized according to the previous procedure. The microstructural and mechanical characterization was carried out in specimens alter solution and artificial aging. Observations in scanning electron microscopy indicated a homogeneous dispersion of La/Ce phases by using both routes; however, mechanical results, in the modified A356 alloy with the ACL in the as-received condi- tion, showed an improvement in the mechanical performance of the A356 alloy over that reinforced with the ACL mechanically milled.
文摘The dissimilar joining of biodegradable magnesium alloy to pure commercial titanium by rotational friction welding with rotational speeds of 1100,1200 and 1300 r/min for the production of bio-screw was investigated.The metallographic analysis revealed that a good joining was obtained at the Ti/Mg alloy joint.On the magnesium alloy side,various regions such as the weld center zone(WCZ),dynamic recrystallization zone(DRX),thermo-mechanically affected zone(TMAZ)and partially deformed zone(PDZ)were observed.The highest tensile and shear strengths were 173 and 103.2 MPa,respectively at a rotational speed of 1300 r/min.The Ti/Mg alloy dissimilar friction welded joint failed at the vicinity of the intermetallic zone containing Ti3Al phase.The hardness values from the base metal magnesium alloy to the joining point increased mainly due to grain refinement(8.57μm in diameter)and the presence of titanium particles,while the hardness values were constant on the titanium side.It was also found that the corrosion rate of the Ti/Mg alloy joint was higher compared with that of the Ti and Mg alloy from the immersion studies.Additionally,the sample with a rotational speed of 1300 r/min showed better biocompatibility and a cell viability of 98.12%due to better corrosion resistance.
基金Project(2011DFR50950)supported by the International Science and Technology Cooperation Program of ChinaProject(51971183)supported by the National Natural Science Foundation of ChinaProject(cstc2019jcyj-msxmX0594)supported by the Natural Science Foundation of Chongqing,China。
文摘The microstructure and mechanical properties of 105 mm thick 5083 aluminum alloy hot rolled plate were investigated by metallurgical microscope, scanning electron microscope and tensile testing machine, and three major characteristic problems in mechanical properties inhomogeneity were explained. The results show that the mechanical properties of the rolled plate are inhomogeneous along the thickness direction. From the surface to the center, the strength shows an inverted "N" shape change and the elongation presents a semi "U" shape change. Several similar structural units composed of long fibrous grains(LFG) and short fibrous grains bands(SFGB) exist in a special layer(Layer 2) adjacent to the surface. This alternating layered distribution of LFG and SFGB is conducive to improving the plasticity by dispersing the plastic deformation concentrated on the boundary line(BL) between them. However, their different deformability will cause the alternation of additional stresses during the hot rolling, leading to the strength reduction. The closer the location to the center of the plate is, the more likely the recovery rather than the recrystallization occurs. This is the possible reason for the unnegligible difference in strength near the central region(Layer 4 and Layer 5).
基金This work was financially supported by Korea Research Foundation of the Korea Government(MOEHRD)(KRF-2005-210-C00024).
文摘Magnetic properties of diluted magnetic semiconductors (DMSs), Ni-doped ZnO materials, prepared by sol-gel method were investigated by measuring magnetization as functions of magnetic field. The Ni content affects the magnetic properties at low sintered temperature but it has few effects on the magnetic properties at high sintered temperature. The sintered temperature has great effects on the magnetic properties of Ni/ZnO at high original mole ratio of Ni/Zn while it has slight effects on the magnetic properties of Ni/ZnO at low original mole ratio of Ni/Zn whatever low or high sintered temperature.
基金The authors are grateful for the financial supports from National Natural Science Foundation of China(51171212)Chongqing Science and Technology Commission(CSTC2012JJJQ50001,CSTC2013jcyjC60001,cstc2012ggB 50003)+1 种基金The National Science and Technology Program of China(2013DFA71070)the Fundamental Research Funds for the Central Universities(CDJZR13138801).
文摘The as-cast and as-extruded Mg–9Li–1Al–xCa alloys(x=0,0.2;wt%)were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of 28.2.The microstructures of the as-cast and as-extruded Mg–9Li–1Al–xCa alloys were observed to investigate the effect of calcium(Ca)element on the Mg–9Li–1Al(LA91)alloy,and the crystallographic calculations between Al_(2)Ca and the matrix(α-Mg andβ-Li phases)were examined on the basis of the edge-to-edge matching model.The experimental results indicate that the addition of 0.2 wt%Ca into LA91 alloy reduce the size of theα-Mg phases in the as-cast alloy and that ofβ-Li phases in the as-extruded alloy due to the Al_(2)Ca particles distributed inside the matrix.Crystallographic calculation results suggested that there is a good crystallographic matching between the matrix and Al_(2)Ca,which confirmed that Al_(2)Ca particles can act as a heterogeneous nucleation site for bothα-Mg andβ-Li phases and were effective grain refiners for LA91 alloy.
基金financially supported by the National Science&Technology Support Program(No.2011BAE22B03-3)the International Science&Technology Cooperation Program of China(No.2011DFA5090)+1 种基金Chongqing Key Science and Technology Projects(No.CTSC-2010AA4045)the Nature Science Foundation Project of Chongqing(No.CSTS-2010BB4068)
文摘The effects of the rare earth element Y addition on mechanical properties and energy absorption of a low Zn content Mg-Zn-Zr system alloy and the deformation temperature of optimized alloy were investigated by room tensile test, optical microscopy （OM）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscope （TEM）. The results show that, after homogenization at 420℃ for 12 h for the as-cast alloys, MgZn phase forms, which decreases the strength of Mg-2.0Zn-0.3Zr alloy with Y content of 0.9 wt%. The tensile strength and elongation of the alloy with a Y addition of 5.8 wt% reach the max value （281 ±2） MPa and （30.1 ± 0.7） %, respectively; the strength and elongation of Mg-2.0Zn-0.3Zr-0.9Y alloy at the optimized extrusion temperature of 330 ℃ reach （321 ± 1） MPa and （21.9 ± 0.7） %, respectively. The energy absorption increases with the increase of Y content, the max value reached 0.79 MJ·m^-3 with Y content of 5.8 wt%, and the energy absorption of Mg-2.0Zn-0.3Zr-0.9Y alloy at the optimized extrusion temperature of 330 ℃ reaches 0.75 MJ·m^-3.
基金the support provided by Islamic Azad University of Najafabad, Iran for this research。
文摘A type of polymer/ceramic coating was introduced on a magnesium-based nanocomposite, and the nanocomposite was evaluated for implant applications.The microstructure, corrosion, and bioactivity of the coated and uncoated samples were assessed.Mechanical alloying followed by sintering was applied to fabricate the Mg–3Zn–0.5Ag–15NiTi nanocomposite substrate.Moreover, different contents of poly(lactic-co-glycolic acid)(PLGA) coatings were studied, and 10 wt% of PLGA content was selected.The scanning electron microscopy(SEM) images of the bulk nanocomposite showed an acceptable homogenous dispersion of the Ni Ti nanoparticles(NPs) in the Mg-based matrix.In the in vitro bioactivity evaluation, following the immersion of the uncoated and coated samples in a simulated body fluid(SBF) solution, the Ca/P atomic ratio demonstrated that the apatite formation amount on the coated sample was greater than that on the uncoated nanocomposite.Furthermore, assessing the corrosion resistance indicated that the coatings on the Mg-based substrate led to a corrosion current density(icorr) that was considerably lower than that of the substrate.Such a condition revealed that the coating would provide an obstacle for the corrosion.Based on this study, the PLGA/hardystonite(HT) composite-coated Mg–3Zn–0.5Ag–15NiTi nanocomposite may be suitably applied as an orthopedic implant biomaterial.
基金the National Natural Science Foundation of China(Project 51531002,51474043)the Ministry of Science&Technology of China(2013DFA71070)+1 种基金the Ministry of Education of China(SRFDR 20130191110018)Chongqing Municipal Government(CSTC2013JCYJC60001,CEC project,Two River Scholar Project and The Chief Scientist Studio Project).
文摘Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.
文摘An investigation was carried out to assess the applicability of transient liquid phase bonding of two dissimilar super-alloys with different interlayers. The effect of using three types of interlayer such as BNi-2, BNi-3, and BNi-9 on microstructure and mechanical properties was studied in the GTD-111/IN-718 system at 1100 ℃ for different bonding time. To determine the compositional changes and microstructure in the joint region, field emission scanning electron microscopy equipped with energy dispersive spectroscopy was utilized. The formation of Ni_(3)B in the athermally solidified zone(ASZ) is controlled by the B content and, accordingly, the morphology of Ni_(3)Si is governed by the Si content. The Cr content might impede the relocation of B from the interlayer into the base metal and the formation of CrB inside the ASZ is dominated by the Cr content. The high micro-hardness of the eutectic compounds is originated from the formation of boride matrixes such as Ni or Cr boride. The shear strength of the joint using BNi-9 after the completion of isothermal solidification is lower compared that that using BNi-3 and BNi-2, which could be related to the absence of Si in the filler metals constituent and the significant presence of Cr in BNi-9.
基金the Natural Sciences and Engineering Research Council of Canada (NSERC)the AUTO21 Network of Centres of Excellence for providing financial support+10 种基金financial support by the Premier’s Research Excellence Award (PREA)NSERC-Discovery Accelerator Supplement (DAS) AwardAutomotive Partnership Canada (APC)Canada Foundation for Innovation (CFI)Ryerson Research Chair (RRC) programthe Ministry of Science and Technology of the People’s Republic of China (2014DFG52810)the National Great Theoretic Research Project of China (2013CB632200)the National Natural Science Foundation of China (Project 51474043)Ministry of Education of the People’s Republic of China (SRFDR 20130191110018)Chongqing Municipal Government (CSTC2013JCYJC60001)Chongqing Science and Technology Commission (CSTC2011gjhz50001) for their financial supports
文摘The aim of this study was to evaluate the strain hardening and hot deformation behavior of asextruded Mg-Zn-Mn （ZM31） magnesium alloy with varying Y contents （0.3, 3.2, and 6 wt%） via compression testing along the extrusion direction at room temperature, 200℃ and 300 ℃. Texture and phases were identified by X-ray diffraction. Alloy ZM31 ＋ 0.3Y consisted of a mixture of fine equiaxed grains and elon- gated grains with 1-phase （Mg3YZno）; alloy ZM31 ＋ 3.2Y contained 1-phase and W-phase （Mg3Y2Zn3）; alloy ZM31 ＋ 6Y had long-period stacking-ordered （LPSO） X-phase （Mg12YZn） and Mg24Y5 particles. With increasing Y content the basal texture became weakened significantly. While alloys ZM31 ＋ 0.3Y and ZM31 ＋ 3.2Y exhibited a skewed true stress-true stain curve with a three-stage strain hardening feature caused by the occurrence of {1072} extension twinning, the true stress-true stain curve of alloy ZM31 ＋ 6Y was normal due to the dislocation slip during compression. With increasing temperature the extent of skewness decreased. While the compressive yield stress, ultimate compressive stress, strain hardening exponent, and hardening capacity all decreased as the temperature increased, the retention of the high- temperature deformation resistance increased with increasing Y content mainly due to the presence of thermally-stable LPSO X-ohase.
文摘Mg alloys have been widely used in automobile and electronic industries because of high specific strength, good castability, etc. However, molten Mg alloys will burn rapidly in air if not protected. To solve this problem, the molten metal should be protected from oxidation by blanketing the surface with flux or protective gases. SF6 gas is widely used for Mg alloys as a cover gas and has proved to be a successful inhibitor. However, the use of SF6 gas is limited because of its high cost and its significant impact on non-global warming potential. Therefore, SF6 gas is being replaced by alternative protection gases. Recent studies show that there has been another attempt by adding CaO into Mg alloys. The aim of this study is to evaluate the effect of CaO on the minimum amount of protective gas, which is necessary not to make ignition in the molten AZ31 and AZ91 Mg alloys.
