Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot presse...Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.展开更多
In order to obtain high-density dual-scale ceramic particles(8.5 wt.%SiC+1.5 wt.%TiC)reinforced Al-Mg Sc-Zr composites with uniform microstructure,50 nm TiC and 7μm SiC particles were pre-dispersed into 15−53μm alum...In order to obtain high-density dual-scale ceramic particles(8.5 wt.%SiC+1.5 wt.%TiC)reinforced Al-Mg Sc-Zr composites with uniform microstructure,50 nm TiC and 7μm SiC particles were pre-dispersed into 15−53μm aluminum alloy powders by low-speed ball milling and mechanical mixing technology,respectively.Then,the effects of laser energy density,power and scanning rate on the density of the composites were investigated based on selective laser melting(SLM)technology.The effect of micron-sized SiC and nano-sized TiC particles on solidification structure,mechanical properties and fracture behaviors of the composites was revealed and analyzed in detail.Interfacial reaction and phase variations in the composites with varying reinforced particles were emphatically considered.Results showed that SiC-TiC particles could significantly improve forming quality and density of the SLMed composites,and the optimal relative density was up to 100%.In the process of laser melting,a strong chemical reaction occurs between SiC and aluminum matrix,and micron-scale acicular Al_(4)SiC_(4) bands were formed in situ.There was no interfacial reaction between TiC particles and aluminum matrix.TiC/Al semi-coherent interface had good bonding strength.Pinning effect of TiC particles in grain boundaries could prevent the equiaxial crystals from growing and transforming into columnar crystals,resulting in grain refinement.The optimal ultimate tensile strength(UTS),yield strength(YS),elongation(EL)and elastic modulus of the SiC-TiC/Al-Mg-Sc-Zr composite were~394 MPa,~262 MPa,~8.2%and~86 GPa,respectively.The fracture behavior of the composites included ductile fracture of Al matrix and brittle cleavage fracture of Al_(4)SiC_(4) phases.A large number of cross-distributed acicular Al_(4)SiC_(4) bands were the main factors leading to premature failure and fracture of SiC-TiC/Al-Mg-Sc-Zr composites.展开更多
Polymer matrix composites(PMC)are extensively been used in many engineering applications.Various natural fibers have emerged as potential replacements to synthetic fibers as reinforcing materials composites owing to t...Polymer matrix composites(PMC)are extensively been used in many engineering applications.Various natural fibers have emerged as potential replacements to synthetic fibers as reinforcing materials composites owing to their fairly better mechanical properties,low cost,environment friendliness and biodegradability.Selection of appropriate constituents of composites for a particular application is a tedious task for a designer/engineer.Impact loading has emerged as the serious threat for the composites used in structural or secondary structural application and demands the usage of appropriate fiber and matrix combination to enhance the energy absorption and mitigate the failure.The objective of the present review is to explore the composite with various fiber and matrix combination used for impact applications,identify the gap in the literature and suggest the potential naturally available fiber and matrix combination of composites for future work in the field of impact loading.The novelty of the present study lies in exploring the combination of naturally available fiber and matrix combination which can help in better energy absorption and mitigate the failure when subjected to impact loading.In addition,the application of multi attributes decision making(MADM)tools is demonstrated for selection of fiber and matrix materials which can serve as a benchmark study for the researchers in future.展开更多
Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric properties.However,their ...Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric properties.However,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather unsatisfactory.In this study,SrAl_(2)Si_(2)O_(8)(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and toughness.Then,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO_(3),Al_(2)O_(3),and SiO_(2) as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were investigated.The thermal shock resistance of BN-SAS ceramic composites was evaluated.Results show that phases of as-preparedBN-SAS ceramic composites are h-BN and h-SrAl_(2)Si_(2)O_(8).With the increase of sintering pressure,the composites’densities increase,and the mechanical properties shew a rising trend followed by a slight decline.At a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m^(1/2),respectively.Composites sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96×10^(-6) K^(-1) in the temperature range from 200 to 1200℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m^(-1)·K^(-1) within the temperature range from room temperature to 1000℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400℃.The maximum residual bending strength is recorded at a temperature difference of 800℃,with a residual strength retention rate of 101%.As the thermal shock temperature difference increase,the degree of oxidation on the ceramic surface and cracks due to thermal stress are also increased gradually.展开更多
Titanium has found extensive use in various engineering applications due to its attractive physical,mechanical, and chemical characteristics. However, titanium has relatively low hardness for use as an armour material...Titanium has found extensive use in various engineering applications due to its attractive physical,mechanical, and chemical characteristics. However, titanium has relatively low hardness for use as an armour material. ZrB2 was incorporated to the Ti matrix to form a Ti-based binary composites. In this study, powder metallurgy techniques were employed to disperse the ceramic particulates throughout the matrix material then consolidated through spark plasma sintering. The composites were densified at1300 ℃, pressure of 50 MPa, and holding time of 5 min. The microstructure and phase analysis of the sintered composites was carried out using SEM and XRD, while the hardness was determined using Vickers' microhardness tester. The SEM and XRD results confirmed the presence of the TiB whiskers which renowned with the improving the hardness of titanium. The hardness of the composite with 10 wt% ZrB_2 showed the highest hardness compared to that obtained for the 5 and 15 wt% ZrB_2 composites which was 495 and 571 Hv respectively.展开更多
Metal matrix composites tiles based on Ti-6Al-4V(Ti64)alloy,reinforced with 10,20,and 40(vol%)of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy(BEPM)and then bonded to...Metal matrix composites tiles based on Ti-6Al-4V(Ti64)alloy,reinforced with 10,20,and 40(vol%)of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy(BEPM)and then bonded together into 3-layer laminated plates using hot isostatic pressing(HIP).The laminates were ballistically tested and demonstrated superior performance.The microstructure and properties of the laminates were analyzed to determine the effect of the BEPM and HIP processing on the ballistic properties of the layered plates.The effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the laminate.Exceptional ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BEPM products by their additional processing using HIP,which provides an unprecedented increase in the hardness of the layered composites.It is argued that the combination of the used two technologies,BEPM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually.展开更多
Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flak...Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flake graphite powders that were evenly loaded with tungsten copper composite powder(RMCBCs-W@Cu)exhibited a low wear rate of 1.63 mm^(3)/h,exhibiting 48.6%reduction in the wear rate relative to RCMBCs without additives(RMCBCs-0).In addition,RMCBCs-W@Cu achieved a low friction coefficient of 0.243 and low electric spark grade.These findings indicate that tungsten copper composite powders provide particle reinforcement and generate a gradation effect for the epoxy resin(i.e.,connecting phase)in RMCBCs,which weakens the wear of RMCBCs caused by fatigue under a cyclic current-carrying wear.展开更多
Continuous carbon fiber reinforced copper matrix composites with 70%(volume fraction) of carbon fibers prepared by squeeze casting technique have been used for investigation of the coefficient of thermal expansion(CTE...Continuous carbon fiber reinforced copper matrix composites with 70%(volume fraction) of carbon fibers prepared by squeeze casting technique have been used for investigation of the coefficient of thermal expansion(CTE) and thermal conductivity.Thermo-physical properties have been measured in both,longitudinal and transversal directions to the fiber orientation.The results showed that Cf/Cu composites may be a suitable candidate for heat sinks because of its good thermo-physical properties e.g.the low CTE(4.18×10-6/K) in longitudinal orientation and(14.98×10-6/K) in transversal orientation at the range of 20-50℃,a good thermal conductivity(87.2 W/m·K) in longitudinal orientation and(58.2 W/m·K) in transversal orientation.Measured CTE and thermal conductivity values are compared with those predicted by several well-known models.Eshelby model gave better results for prediction of the CTE and thermal conductivity of the unidirectional composites.展开更多
In the present manuscript numerical analysis on the ballistic performance of a tungsten particle/metallic glass matrix(WP/MG) composite rod is conducted by integrating with related experimental investigations. In the ...In the present manuscript numerical analysis on the ballistic performance of a tungsten particle/metallic glass matrix(WP/MG) composite rod is conducted by integrating with related experimental investigations. In the corresponding finite element method(FEM) simulations a modified coupled thermomechanical constitutive model is employed to describe the mechanical properties of metallic glass(MG)matrix, and geometrical models of the WP/MG composite rod are established based on its inner structure. The deformation and failure characteristics of the rod and target materials are analyzed in detail,and the influences of various factors on the ballistic performance of the WP/MG composite long rod are discussed. Related analysis demonstrates that the penetrating performance of the WP/MG rod is similar to that of the tungsten fiber/metallic glass matrix(WF/MG) composite long rod, i.e., a "self-sharpening" behavior also occurs during the penetration process, and correspondingly its penetrating capability is better than that of the tungsten heavy alloy(WHA) rod. However, the mass erosion manner of the WP/MG rod is different and the erosion is relatively severe, thus its penetrating capability is a little lower compared with that of the WF/MG one. Moreover, the impact velocity and the target strength have significant influences on the ballistic performance of the WP/MG composite rod, whereas the effect of initial nose shape is very little.展开更多
In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane trea...In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane treatment on fibre. The composites were fabricated by laying 20, 30 and 40vol% of e-glass fibre into epoxy resin matrix. The e-glass fibre woven mat was surface treated by an amine functional coupling agent 3-Aminopropyletrimethoxysilane(APTMS). The fibres were surface treated by aqueous solution method and thermo assisted to create silinol groups. Similarly for acid treatment H_2SO_4 and base treatment Na OH with 1N concentration was used for surface treating the fibres. Effectiveness of silane treatment on glass fibre was compared by inter laminar shear strength test according to ASTM D 2344.Drilling process with varying diameter drill bit and varying cutting speed was applied to check the composites for their delamination resistance while machining. Maximum improvement of 15%, 12.5% and9%(20, 30 and 40 vol %) on ILSS was achieved for siliconized e-glass fibre reinforced epoxy composites.The scanning electron microscopy images revealed that no fibre pull out was present on fractured surfaces of composites which contains siliconized e-glass fibre. Similarly better dimensional accuracy was achieved on drilling process for composites contains siliconized e-glass fibre.展开更多
High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters ...High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious challenge.The purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)composites.The composite laminates are fabricated according to orthogonal experiments via the thermoforming method.The mechanical performance is investigated in terms of crystallization properties and fracture morphology characterizations.Experimental results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing parameters.The increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the composites.This is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural modulus.As well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.展开更多
Ti and Ti alloys are wonderful metal materials,showing excellent corrosion resistance,high specific strength and outstanding biocompatibility[1-2].They have been widely used in a variety of industries,including aerosp...Ti and Ti alloys are wonderful metal materials,showing excellent corrosion resistance,high specific strength and outstanding biocompatibility[1-2].They have been widely used in a variety of industries,including aerospace engineering,biomedical enginee-ring,off-shore drilling,automobile industry and even jewelry industry[1-2].To further improve their performance for satisfying the ever increasing challenging demands,Ti-based metal matrix composite becomes a cutting-edge research direction[3-4].However,intrinsic properties of most Ti materials,such as low thermal conductivity,high chemical reactivity and hexagonal close packed crystal structure,make their machining rather difficult and also push up the cost of using Ti products.Considering reinforcement phases of Ti are often hard-and-refractory ceramic particles,it is even harder to fabricate Ti composite using conventional fabrication methods[1-4].展开更多
This work describes the preparation and study of the properties of composite nanoparticles prepared by the sol-gel method which consists of two materials(Al2 O3-CaO),and study the effect of these nanoparticles on the ...This work describes the preparation and study of the properties of composite nanoparticles prepared by the sol-gel method which consists of two materials(Al2 O3-CaO),and study the effect of these nanoparticles on the mechanical behavior of a polymer blend(EP 4%+96%UPE).The powder was evaluated by X-ray diffraction analysis,scanning electron microscopy analysis(SEM),particle size analysis,and energy dispersive X-ray analysis(EDX).The mechanical behavior of the co mposite material was assessed by tensile test,bending test and hardness test.The evaluation results of the composite nanoparticles showed good distribution of the chemical composition between aluminum oxide and calcium oxide,smoothness in particles’size at calcination in high and low temperatures,formation of different shapes of nanoparticles and different(kappa and gamma)phases of the Al2 O particles.The results of mechanical behavior tests showed marked improvement in the mechanical properties of the resulted composite material,especially at 1.5%,compared with polymer blend material without nano powder addition.The tensile properties improved about(24 and 14.9)%and bending resistance about(23.5 and16.8)%and hardness by(25 and 22)%when adding particles of size(63.8 and 68.6)respectively.Therefore,this reflects the efficiency of the proposed method to manufacture the nanoco mposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications,especially in the fabrication of artificial limbs.展开更多
SiC foam ceramic reinforced aluminum matrix composites(SFCAMCs)were prepared by squeeze casting aluminum alloy(Al-23Si)into the SiC foam ceramic with different pore sizes,and the corrosion behavior of the SFCAMCs was ...SiC foam ceramic reinforced aluminum matrix composites(SFCAMCs)were prepared by squeeze casting aluminum alloy(Al-23Si)into the SiC foam ceramic with different pore sizes,and the corrosion behavior of the SFCAMCs was studied in NaCl solutions.Static immersion corrosion tests were conducted at 20°C,50°C and 80°C,respectively.Corrosion morphology and products were analyzed by scanning electron microscope,energy dispersive system and X-ray diffraction.It was found that the corrosion rate of SFCAMCs increases as the temperature rising,and the bigger pore size of SiC foam ceramic reinforcement,the better corrosion resistance of SFCAMCs.展开更多
Mg-6%Zn-10%β-Ca3(PO4)2 composite was prepared through powder metallurgy methods with different chitosan coatings on its surface. The properties of the chitosan coatings on the surface of Mg-6%Zn-10%β-Ca3(PO4)2 compo...Mg-6%Zn-10%β-Ca3(PO4)2 composite was prepared through powder metallurgy methods with different chitosan coatings on its surface. The properties of the chitosan coatings on the surface of Mg-6%Zn-10%β-Ca3(PO4)2 composite, such as the adhesion ability, the corrosion behavior and the cytotoxicity properties, were investigated, and the microstructure of the chitosan coating was observed by scanning electron microscope(SEM). The results show that chitosan coating improves the corrosion resistance of the magnesium composite specimens significantly. Mg-6%Zn-10%β-Ca3(PO4)2 composite specimens exhibit good corrosion resistance and low p H values in simulated body fluid(SBF) at 37 °C in the immersion test with 7-layer chitosan coating whose relative molecular mass is 30×104 Da. The cytotoxicity tests indicate that Mg-6%Zn-10%β-Ca3(PO4)2 with chitosan coating is nontoxic with a cytotoxicity grade of zero against L-929 cells, which is better than that of uncoated composites.展开更多
In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are so...In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are solutionizing time,aging temperature,and aging time.The experiments were performed on an universal testing machine according to centre rotatable design matrix.A mathematical model was developed with the main and interactive effects of the parameters considered.The analysis of variance technique was used to check the adequacy of the developed model.The optimum parameters were obtained for maximum tensile strength.Fractographic examination shows the cracks and dimples on the fractured surfaces of heat-treated specimen.展开更多
Electroformed diamond tools have been used for many years in grinding and cutting fields while electrodeposited diamond composite coatings have been widely studied due to their desirable hardness,wear and corrosion re...Electroformed diamond tools have been used for many years in grinding and cutting fields while electrodeposited diamond composite coatings have been widely studied due to their desirable hardness,wear and corrosion resistance.This article reports the detrimental impact of diamond magnetism on the composites microstructure and gives explanations.Microstructure differences between composites that,respectively,contained no-further-treated diamond,magnetism-strengthening treated diamond and magnetism weakening treated diamond were carefully observed.It is shown that diamond magnetization treatment drastically harms the composite microstructure(e.g.,roughening the coating surface,coarsening the matrix grain,and more seriously,reducing the mechanical retention of diamond grains in the matrix) while demagnetization treatment does the opposite.All the observed facts could be explained by the electromagnetic interaction between magnetic fields produced by magnetic diamond grains and electric current(moving cations) during the electrodeposition process.展开更多
In this paper,the 2.6 vol%TiBw/Ti6Al4V composites with network architecture were fabricated by hot press sintering(HPS)at 1100℃ for 1 h,and the quantitative relationships between phases and heat treatment temperature...In this paper,the 2.6 vol%TiBw/Ti6Al4V composites with network architecture were fabricated by hot press sintering(HPS)at 1100℃ for 1 h,and the quantitative relationships between phases and heat treatment temperatures were established.The results showed that the volume fraction phases changed linearly with a range of solution temperature(930-1010℃)and aging temperature(400-600℃).Moreover,the composites with equiaxed microstructure were obtained due to the static recrystallization after solution treated at 950℃ for 1 h and aging treated at 600℃ for 12 h.The ultimate high temperature tensile strengths were 772,658,392 and 182 MPa,and the elongations were 9.1%,12.5%,28.6%and 35.3%at 400,500,600 and 700℃,respectively.In addition,fractured morphology analysis indicated the excellent strengthening effect of TiBw at a temperature below 600℃.However,the strengthening effect was significantly reduced due to the debonding of matrix and TiBw at 700℃ and caused the cracks to propagate along the grain boundary.展开更多
Titanium metal matrix composite(Ti-MMC)has excellent features and capabilities which can be considered a potential candidate to replace commercial titanium and superalloys within an extensive range of products and ind...Titanium metal matrix composite(Ti-MMC)has excellent features and capabilities which can be considered a potential candidate to replace commercial titanium and superalloys within an extensive range of products and industrial sectors.Regardless of the superior features in Ti-MMC,however,referring to several factors including high unit cost and existence of rigid and abrasive ceramic particles in the generated matrices of the work part,the Ti-MMC is grouped as extremely difficult to cut with a poor level of machinability.Furthermore,adequate process parameters for machining Ti-MMCs under several lubrication methods are rarely studied.Therefore,adequate knowledge of this regard is strongly demanded.Among machinability attributes,ultrafine particles(UFPs)and fine particles(FPs)have been selected as the main machinability attributes and the factors leading to minimized emission have been studied.According to experimental observations,despite the type of coating used,the use of higher levels of flow rate led to less UFPs,while no significant effects were observed on UFPs.Under similar cutting conditions,higher levels of FPs were recorded under the use of uncoated inserts.Moreover,cutting speed had no significant influence on UFPs;nevertheless,it significantly affects the FPs despite the type of insert used.展开更多
基金Project(2021YFC2900200)supported by the National Key Research and Development Project of ChinaProject(20230203114SF)supported by the Key Research and Development Project of Jilin Province,China。
文摘Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.
基金Project(2022J318)supported by the Natural Science Foundation of Ningbo,ChinaProject(2021A1515110525)supported by the Guangdong Basic and Applied Basic Research Foundation,ChinaProject(2022QN05023)supported by the Inner Mongolia Natural Science Foundation Youth Project,China。
文摘In order to obtain high-density dual-scale ceramic particles(8.5 wt.%SiC+1.5 wt.%TiC)reinforced Al-Mg Sc-Zr composites with uniform microstructure,50 nm TiC and 7μm SiC particles were pre-dispersed into 15−53μm aluminum alloy powders by low-speed ball milling and mechanical mixing technology,respectively.Then,the effects of laser energy density,power and scanning rate on the density of the composites were investigated based on selective laser melting(SLM)technology.The effect of micron-sized SiC and nano-sized TiC particles on solidification structure,mechanical properties and fracture behaviors of the composites was revealed and analyzed in detail.Interfacial reaction and phase variations in the composites with varying reinforced particles were emphatically considered.Results showed that SiC-TiC particles could significantly improve forming quality and density of the SLMed composites,and the optimal relative density was up to 100%.In the process of laser melting,a strong chemical reaction occurs between SiC and aluminum matrix,and micron-scale acicular Al_(4)SiC_(4) bands were formed in situ.There was no interfacial reaction between TiC particles and aluminum matrix.TiC/Al semi-coherent interface had good bonding strength.Pinning effect of TiC particles in grain boundaries could prevent the equiaxial crystals from growing and transforming into columnar crystals,resulting in grain refinement.The optimal ultimate tensile strength(UTS),yield strength(YS),elongation(EL)and elastic modulus of the SiC-TiC/Al-Mg-Sc-Zr composite were~394 MPa,~262 MPa,~8.2%and~86 GPa,respectively.The fracture behavior of the composites included ductile fracture of Al matrix and brittle cleavage fracture of Al_(4)SiC_(4) phases.A large number of cross-distributed acicular Al_(4)SiC_(4) bands were the main factors leading to premature failure and fracture of SiC-TiC/Al-Mg-Sc-Zr composites.
文摘Polymer matrix composites(PMC)are extensively been used in many engineering applications.Various natural fibers have emerged as potential replacements to synthetic fibers as reinforcing materials composites owing to their fairly better mechanical properties,low cost,environment friendliness and biodegradability.Selection of appropriate constituents of composites for a particular application is a tedious task for a designer/engineer.Impact loading has emerged as the serious threat for the composites used in structural or secondary structural application and demands the usage of appropriate fiber and matrix combination to enhance the energy absorption and mitigate the failure.The objective of the present review is to explore the composite with various fiber and matrix combination used for impact applications,identify the gap in the literature and suggest the potential naturally available fiber and matrix combination of composites for future work in the field of impact loading.The novelty of the present study lies in exploring the combination of naturally available fiber and matrix combination which can help in better energy absorption and mitigate the failure when subjected to impact loading.In addition,the application of multi attributes decision making(MADM)tools is demonstrated for selection of fiber and matrix materials which can serve as a benchmark study for the researchers in future.
基金National Natural Science Foundation of China (52072088, 52072089)Natural Science Foundation of Heilongjiang Province (LH2023E061)+1 种基金Scientific and Technological Innovation Leading Talent of Harbin Manufacturing (2022CXRCCG001)Fundamental Research Funds for the Central Universities (3072023CFJ1003)。
文摘Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric properties.However,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather unsatisfactory.In this study,SrAl_(2)Si_(2)O_(8)(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and toughness.Then,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO_(3),Al_(2)O_(3),and SiO_(2) as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were investigated.The thermal shock resistance of BN-SAS ceramic composites was evaluated.Results show that phases of as-preparedBN-SAS ceramic composites are h-BN and h-SrAl_(2)Si_(2)O_(8).With the increase of sintering pressure,the composites’densities increase,and the mechanical properties shew a rising trend followed by a slight decline.At a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m^(1/2),respectively.Composites sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96×10^(-6) K^(-1) in the temperature range from 200 to 1200℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m^(-1)·K^(-1) within the temperature range from room temperature to 1000℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400℃.The maximum residual bending strength is recorded at a temperature difference of 800℃,with a residual strength retention rate of 101%.As the thermal shock temperature difference increase,the degree of oxidation on the ceramic surface and cracks due to thermal stress are also increased gradually.
基金supported financially by the National Research Foundationthe support from the the Tshwane University of Technology, Pretoria, South Africa which helped to accomplish this work
文摘Titanium has found extensive use in various engineering applications due to its attractive physical,mechanical, and chemical characteristics. However, titanium has relatively low hardness for use as an armour material. ZrB2 was incorporated to the Ti matrix to form a Ti-based binary composites. In this study, powder metallurgy techniques were employed to disperse the ceramic particulates throughout the matrix material then consolidated through spark plasma sintering. The composites were densified at1300 ℃, pressure of 50 MPa, and holding time of 5 min. The microstructure and phase analysis of the sintered composites was carried out using SEM and XRD, while the hardness was determined using Vickers' microhardness tester. The SEM and XRD results confirmed the presence of the TiB whiskers which renowned with the improving the hardness of titanium. The hardness of the composite with 10 wt% ZrB_2 showed the highest hardness compared to that obtained for the 5 and 15 wt% ZrB_2 composites which was 495 and 571 Hv respectively.
基金funding from the NATO Agency Science for Peace and Security (#G5787)Ballistic investigations were co-financed by Military University of Technology in Warsaw under research project UGB 829/2023/WATSeparate works made in G.V.Kurdyumov Institute for Metal Physics of N.A.S.of Ukraine were partially financially supported by N.A.S.of Ukraine within the frames of project#III09-18。
文摘Metal matrix composites tiles based on Ti-6Al-4V(Ti64)alloy,reinforced with 10,20,and 40(vol%)of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy(BEPM)and then bonded together into 3-layer laminated plates using hot isostatic pressing(HIP).The laminates were ballistically tested and demonstrated superior performance.The microstructure and properties of the laminates were analyzed to determine the effect of the BEPM and HIP processing on the ballistic properties of the layered plates.The effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the laminate.Exceptional ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BEPM products by their additional processing using HIP,which provides an unprecedented increase in the hardness of the layered composites.It is argued that the combination of the used two technologies,BEPM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually.
基金Projects(51772081,51837009,51971091)supported by the National Natural Science Foundation of ChinaProject(HFZL2018CXY003-4)supported by the Industry-University-Research Cooperation of AECC,ChinaProject(kq1902046)supported by the Major Science and Technology Projects of Changsha City,China。
文摘Resin matrix carbon brush composites(RMCBCs)are critical materials for high-powered electric tools.However,effectively improving their wear resistance and heat dissipation remains a challenge.RMCBCs prepared with flake graphite powders that were evenly loaded with tungsten copper composite powder(RMCBCs-W@Cu)exhibited a low wear rate of 1.63 mm^(3)/h,exhibiting 48.6%reduction in the wear rate relative to RCMBCs without additives(RMCBCs-0).In addition,RMCBCs-W@Cu achieved a low friction coefficient of 0.243 and low electric spark grade.These findings indicate that tungsten copper composite powders provide particle reinforcement and generate a gradation effect for the epoxy resin(i.e.,connecting phase)in RMCBCs,which weakens the wear of RMCBCs caused by fatigue under a cyclic current-carrying wear.
文摘Continuous carbon fiber reinforced copper matrix composites with 70%(volume fraction) of carbon fibers prepared by squeeze casting technique have been used for investigation of the coefficient of thermal expansion(CTE) and thermal conductivity.Thermo-physical properties have been measured in both,longitudinal and transversal directions to the fiber orientation.The results showed that Cf/Cu composites may be a suitable candidate for heat sinks because of its good thermo-physical properties e.g.the low CTE(4.18×10-6/K) in longitudinal orientation and(14.98×10-6/K) in transversal orientation at the range of 20-50℃,a good thermal conductivity(87.2 W/m·K) in longitudinal orientation and(58.2 W/m·K) in transversal orientation.Measured CTE and thermal conductivity values are compared with those predicted by several well-known models.Eshelby model gave better results for prediction of the CTE and thermal conductivity of the unidirectional composites.
基金supported by the Science and Technology Development Fund (2015B0201025)the key subject "Computational Solid Mechanics" of China Academy of Engineering Physics+1 种基金the National Outstanding Young Scientists Foundation of China (11225213)the National Natural Science Foundation of China (11521062,11602258)
文摘In the present manuscript numerical analysis on the ballistic performance of a tungsten particle/metallic glass matrix(WP/MG) composite rod is conducted by integrating with related experimental investigations. In the corresponding finite element method(FEM) simulations a modified coupled thermomechanical constitutive model is employed to describe the mechanical properties of metallic glass(MG)matrix, and geometrical models of the WP/MG composite rod are established based on its inner structure. The deformation and failure characteristics of the rod and target materials are analyzed in detail,and the influences of various factors on the ballistic performance of the WP/MG composite long rod are discussed. Related analysis demonstrates that the penetrating performance of the WP/MG rod is similar to that of the tungsten fiber/metallic glass matrix(WF/MG) composite long rod, i.e., a "self-sharpening" behavior also occurs during the penetration process, and correspondingly its penetrating capability is better than that of the tungsten heavy alloy(WHA) rod. However, the mass erosion manner of the WP/MG rod is different and the erosion is relatively severe, thus its penetrating capability is a little lower compared with that of the WF/MG one. Moreover, the impact velocity and the target strength have significant influences on the ballistic performance of the WP/MG composite rod, whereas the effect of initial nose shape is very little.
文摘In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane treatment on fibre. The composites were fabricated by laying 20, 30 and 40vol% of e-glass fibre into epoxy resin matrix. The e-glass fibre woven mat was surface treated by an amine functional coupling agent 3-Aminopropyletrimethoxysilane(APTMS). The fibres were surface treated by aqueous solution method and thermo assisted to create silinol groups. Similarly for acid treatment H_2SO_4 and base treatment Na OH with 1N concentration was used for surface treating the fibres. Effectiveness of silane treatment on glass fibre was compared by inter laminar shear strength test according to ASTM D 2344.Drilling process with varying diameter drill bit and varying cutting speed was applied to check the composites for their delamination resistance while machining. Maximum improvement of 15%, 12.5% and9%(20, 30 and 40 vol %) on ILSS was achieved for siliconized e-glass fibre reinforced epoxy composites.The scanning electron microscopy images revealed that no fibre pull out was present on fractured surfaces of composites which contains siliconized e-glass fibre. Similarly better dimensional accuracy was achieved on drilling process for composites contains siliconized e-glass fibre.
基金financial support of the National Natural Science Foundation of China(NO.11902255,U1837601 and 52090051).
文摘High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious challenge.The purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)composites.The composite laminates are fabricated according to orthogonal experiments via the thermoforming method.The mechanical performance is investigated in terms of crystallization properties and fracture morphology characterizations.Experimental results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing parameters.The increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the composites.This is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural modulus.As well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.
文摘Ti and Ti alloys are wonderful metal materials,showing excellent corrosion resistance,high specific strength and outstanding biocompatibility[1-2].They have been widely used in a variety of industries,including aerospace engineering,biomedical enginee-ring,off-shore drilling,automobile industry and even jewelry industry[1-2].To further improve their performance for satisfying the ever increasing challenging demands,Ti-based metal matrix composite becomes a cutting-edge research direction[3-4].However,intrinsic properties of most Ti materials,such as low thermal conductivity,high chemical reactivity and hexagonal close packed crystal structure,make their machining rather difficult and also push up the cost of using Ti products.Considering reinforcement phases of Ti are often hard-and-refractory ceramic particles,it is even harder to fabricate Ti composite using conventional fabrication methods[1-4].
文摘This work describes the preparation and study of the properties of composite nanoparticles prepared by the sol-gel method which consists of two materials(Al2 O3-CaO),and study the effect of these nanoparticles on the mechanical behavior of a polymer blend(EP 4%+96%UPE).The powder was evaluated by X-ray diffraction analysis,scanning electron microscopy analysis(SEM),particle size analysis,and energy dispersive X-ray analysis(EDX).The mechanical behavior of the co mposite material was assessed by tensile test,bending test and hardness test.The evaluation results of the composite nanoparticles showed good distribution of the chemical composition between aluminum oxide and calcium oxide,smoothness in particles’size at calcination in high and low temperatures,formation of different shapes of nanoparticles and different(kappa and gamma)phases of the Al2 O particles.The results of mechanical behavior tests showed marked improvement in the mechanical properties of the resulted composite material,especially at 1.5%,compared with polymer blend material without nano powder addition.The tensile properties improved about(24 and 14.9)%and bending resistance about(23.5 and16.8)%and hardness by(25 and 22)%when adding particles of size(63.8 and 68.6)respectively.Therefore,this reflects the efficiency of the proposed method to manufacture the nanoco mposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications,especially in the fabrication of artificial limbs.
基金Project(00008713)supported by the Program of the Science and Technology Creative Team of Universities in Jiangxi,ChinaProject(2013-KLP-04)supported by the Open Foundation of Jiangxi Key Laboratory for Advanced Copper and Tungsten Materials,China
文摘SiC foam ceramic reinforced aluminum matrix composites(SFCAMCs)were prepared by squeeze casting aluminum alloy(Al-23Si)into the SiC foam ceramic with different pore sizes,and the corrosion behavior of the SFCAMCs was studied in NaCl solutions.Static immersion corrosion tests were conducted at 20°C,50°C and 80°C,respectively.Corrosion morphology and products were analyzed by scanning electron microscope,energy dispersive system and X-ray diffraction.It was found that the corrosion rate of SFCAMCs increases as the temperature rising,and the bigger pore size of SiC foam ceramic reinforcement,the better corrosion resistance of SFCAMCs.
基金Project(2012zzts068) supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(2010fj3091) supported by the Open Funding of State Key Laboratory of Powder Metallurgy and Science&Technology Foundation,China
文摘Mg-6%Zn-10%β-Ca3(PO4)2 composite was prepared through powder metallurgy methods with different chitosan coatings on its surface. The properties of the chitosan coatings on the surface of Mg-6%Zn-10%β-Ca3(PO4)2 composite, such as the adhesion ability, the corrosion behavior and the cytotoxicity properties, were investigated, and the microstructure of the chitosan coating was observed by scanning electron microscope(SEM). The results show that chitosan coating improves the corrosion resistance of the magnesium composite specimens significantly. Mg-6%Zn-10%β-Ca3(PO4)2 composite specimens exhibit good corrosion resistance and low p H values in simulated body fluid(SBF) at 37 °C in the immersion test with 7-layer chitosan coating whose relative molecular mass is 30×104 Da. The cytotoxicity tests indicate that Mg-6%Zn-10%β-Ca3(PO4)2 with chitosan coating is nontoxic with a cytotoxicity grade of zero against L-929 cells, which is better than that of uncoated composites.
文摘In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are solutionizing time,aging temperature,and aging time.The experiments were performed on an universal testing machine according to centre rotatable design matrix.A mathematical model was developed with the main and interactive effects of the parameters considered.The analysis of variance technique was used to check the adequacy of the developed model.The optimum parameters were obtained for maximum tensile strength.Fractographic examination shows the cracks and dimples on the fractured surfaces of heat-treated specimen.
基金This work was supported by Henan Agricultural University,the Natural Science Foundation of Henan Province(0411051300)the Project for Excel-lent University Teachers under the supervision of Henan Provincial Bureau of Education.
文摘Electroformed diamond tools have been used for many years in grinding and cutting fields while electrodeposited diamond composite coatings have been widely studied due to their desirable hardness,wear and corrosion resistance.This article reports the detrimental impact of diamond magnetism on the composites microstructure and gives explanations.Microstructure differences between composites that,respectively,contained no-further-treated diamond,magnetism-strengthening treated diamond and magnetism weakening treated diamond were carefully observed.It is shown that diamond magnetization treatment drastically harms the composite microstructure(e.g.,roughening the coating surface,coarsening the matrix grain,and more seriously,reducing the mechanical retention of diamond grains in the matrix) while demagnetization treatment does the opposite.All the observed facts could be explained by the electromagnetic interaction between magnetic fields produced by magnetic diamond grains and electric current(moving cations) during the electrodeposition process.
基金Project(51905123)supported by the National Natural Science Foundation of ChinaProject(ZR2019MEM037)supported by the Natural Science Foundation of Shandong Province,China。
文摘In this paper,the 2.6 vol%TiBw/Ti6Al4V composites with network architecture were fabricated by hot press sintering(HPS)at 1100℃ for 1 h,and the quantitative relationships between phases and heat treatment temperatures were established.The results showed that the volume fraction phases changed linearly with a range of solution temperature(930-1010℃)and aging temperature(400-600℃).Moreover,the composites with equiaxed microstructure were obtained due to the static recrystallization after solution treated at 950℃ for 1 h and aging treated at 600℃ for 12 h.The ultimate high temperature tensile strengths were 772,658,392 and 182 MPa,and the elongations were 9.1%,12.5%,28.6%and 35.3%at 400,500,600 and 700℃,respectively.In addition,fractured morphology analysis indicated the excellent strengthening effect of TiBw at a temperature below 600℃.However,the strengthening effect was significantly reduced due to the debonding of matrix and TiBw at 700℃ and caused the cracks to propagate along the grain boundary.
基金financial support received from Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT)
文摘Titanium metal matrix composite(Ti-MMC)has excellent features and capabilities which can be considered a potential candidate to replace commercial titanium and superalloys within an extensive range of products and industrial sectors.Regardless of the superior features in Ti-MMC,however,referring to several factors including high unit cost and existence of rigid and abrasive ceramic particles in the generated matrices of the work part,the Ti-MMC is grouped as extremely difficult to cut with a poor level of machinability.Furthermore,adequate process parameters for machining Ti-MMCs under several lubrication methods are rarely studied.Therefore,adequate knowledge of this regard is strongly demanded.Among machinability attributes,ultrafine particles(UFPs)and fine particles(FPs)have been selected as the main machinability attributes and the factors leading to minimized emission have been studied.According to experimental observations,despite the type of coating used,the use of higher levels of flow rate led to less UFPs,while no significant effects were observed on UFPs.Under similar cutting conditions,higher levels of FPs were recorded under the use of uncoated inserts.Moreover,cutting speed had no significant influence on UFPs;nevertheless,it significantly affects the FPs despite the type of insert used.
