最新刊期
卷 40 ， 期 7 ， 2020
- 摘要：Numerical simulation of squeeze casting A356 aluminum alloy component was performed by the ProCAST software.The results show that solidification of component started from the contact surface between aluminum melt and die.The final solidification location is located at the center of corner of wheel model.Solidification time is increased with an increase of pouring temperature and die temperature,however it is decreased with an increase of specific pressure.Maximum effective stress occurrs in the corner of component,while the central region has the minimum effective stress.With the increase of pouring temperature or die temperature,maximum effective stress is decreased.The optimized process parameters were presented such as pouring temperature of 680～720℃,die temperature of 200～300 ℃ and specific pressure of more than 200 MPa by numerical simulation.The results of the validation experiment show that A356 aluminum alloy components with desirable surface quality,complete filling and absence of defects can be produced successfully via squeeze casting under the optimized process parameters.关键词：A356 Aluminum Alloy;Squeeze Casting;Numerical Simulation;Temperature;Specific Pressure
- 4
- |
- 165
- |
- 0
发布时间：2023-12-18 - 摘要：Near-eutectic Al-12.35Si alloy containing various alloying elements was modified by the rare earth La element through adding the Al-La master alloy,and effects of the addition amount（0.1%～0.8%）of La on the microstructure and mechanical properties of Al-Si alloy were investigated.The results reveal that the proper addition amount of La can reduce the size of long needle-like eutectic silicon,refine the second phase,and reduce the primaryα-Al secondary dendrite arm spacing（SDAP）.Excessive La can cause excessive deterioration,resulting in coarsening of the alloy structure.When the La content is 0.2%,the Al-Si alloy has the desirable modified solidification structure and mechanical properties,where the tensile strength of alloy is increased from 168 MPa to 188 MPa,and the elongation is increased from 0.44% to 0.53%.With the increase of La content,both the strength and plasticity of the alloy are declined.关键词：Near-eutectic Al-Si Alloy;Modification;Rare Earth La;Mechanical Properties
- 2
- |
- 45
- |
- 0
发布时间：2023-12-18 - 摘要：An as-extruded Mg-10Li-3Al-1Zn-0.3Mn alloy was treated by solution and aging at different temperatures.The microstructure and mechanical properties of the alloy were analyzed by OM,XRD and hardness testing.The results show that the as-extruded alloy is composed ofα-Mg,β-Li and MgLiAl2 phase.α-Mg phase is distributed in the alloy in blocks of different sizes with low hardness（46.8 HV）.The hardness of the alloy is increased gradually with the increase of solution temperature.α-Mg phase is dissolved into the matrix alloy with solid solution at different temperatures for 30 min,and the hardness of the alloy is increased with increasing of solution temperature which result in the increase ofα-Mg phase solution.The hardness of the alloy reaches up to 110 HV after solution at 460℃ for 30 min,which is 135% higher than that of extruded alloy.The hardness of the alloy is decreased with the increase of solution time at 460℃ for 30,60 and 90 min.After artificial aging and natural aging,the hardness of the alloy is decreased.After aging at 70℃ for 1 hour or artificial aging for 20 days,the hardness of the alloy is finally stabilized at about 75 HV,which is about 60%higher than that of the extruded alloy.关键词：Mg-Li Alloy;Solution and Aging;Microstructure;Mechanical Properties
- 2
- |
- 142
- |
- 0
发布时间：2023-12-18 - 摘要：The interaction energies of solute atoms with edge dislocation pairs in Cu-Ni-Sn solid solutions were calculated by first principles.The results show that the dislocation has a strong force on Sn atom and it is increased with the increase of Ni content in the matrix.The maximum energy difference of dislocations acting on a single Sn atom is about 89.83 kJ/mol at different positions in pure copper matrix,and that on single Sn atom at different positions in（Cu,Ni）matrix containing 20% Ni is about 128.25 kJ/mol.The preferred distribution of Sn atoms is at the Gposition just below the front edge dislocations,and the Sn atoms far away from the dislocations converges around the Gposition under the action of energy difference.Dislocation in solid solution has a weak interaction energy to Ni atom（the maximum energy difference about 18.87 kJ/mol）,and the preferential distribution of Ni atom under dislocation is not obvious.关键词：Cu-Ni-Sn Solid Solution;First Principles;Interaction
- 2
- |
- 101
- |
- 0
发布时间：2023-12-18 - 摘要：<正>针对航空航天、精密仪器等领域对于材料减震、吸能等方面的性能需求,中国科学院金属研究所材料疲劳与断裂实验室刘增乾、张哲峰,钛合金研究部李述军、杨锐等与美国加州大学伯克利分校、中国工程物理研究院开展合作,借鉴天然生物材料三维互穿微观结构的理念,将镁熔融浸渗至增材制造的镍钛合金骨架,构筑成轻质、高强、高阻尼、高吸能镁-镍钛仿生复合材料。微观三维互穿仿生结构不仅实现了镍钛增强相与镁基体在优势性能上的互补与结合,而且赋予材料形状记忆与自修复功能。首先,组成相在三维空间相互穿插有利于促进相互间的应力传递,弱化应力集中,使两相的变形更加协调,更好地发挥了镍
- 5
- |
- 174
- |
- 0
发布时间：2023-12-18 - 摘要：<正>2020年6月16日,意特佩雷斯高斯第一台在国内生产的压铸机——TF1850无曲拐两板压铸机正式交付于济南慧成铸造有限公司。接下来将对设备安装调试,预计于7月完成调试投入运行。TF1850是诺瑞肯集团中国常州工厂制造的第一款无曲拐两板高压压铸机,同时也是首台在中国本土制造的意
- 2
- |
- 6
- |
- 0
发布时间：2023-12-18 - 摘要：<正>据市场研究公司Dell’Oro报告指出,第一季度,移动核心网络设备市场同比增长了10%。随着中兴、华为、诺基亚、爱立信、思科等主要通信设备进入需求旺盛期,通讯基站壳体、散热片、腔体滤波器等压铸件也迎来庞大的市场需求。基站结构件市场需求旺盛,同时也带动了压铸机的市场需求。为配合5G通讯结构件超薄、轻量化、高导热需
- 2
- |
- 42
- |
- 0
发布时间：2023-12-18 - 摘要：<正>广东省铸造行业协会统计数据,目前,广东省规模以上铸造企业（含黑色铸造、有色铸造及压铸）超过1000家。2019年,广东省黑色金属铸件产量331万t,全国占比8%;有色金属铸件117万t,压铸件产量占全国总产量15%;全省铸造市场总值916亿元。产品大类及配套产业包括:①汽车、摩托车、船舶、柴油机、铸管等;②工程机械、风电、压铸机、注塑机、陶瓷机械、
- 2
- |
- 24
- |
- 0
发布时间：2023-12-18 - 摘要：<正>来自海关总署的数据显示,2020年5月中国镁产品总出口量2.54万t,环比减少33.5%,同比减少27.6%。自3月起,受海外疫情影响,我国镁锭及下游镁产品的出口量持续减少。据SMM调研,有府谷地区镁锭生产厂表示,5月仅有少量日韩地区和欧洲地区的成交,大部分镁锭的出口订单均延后或者取消;镁粉和镁合金的出口缩减更为严重,镁粉厂和镁合金厂目前的大部分
- 2
- |
- 11
- |
- 0
发布时间：2023-12-18 - 摘要：<正>汽车产销量的继续增加带动汽车用铝量继续增加。根据卓创监测数据显示,2020年5月份中国汽车用铝量为28.44万t,环比增长4.04%,同比上涨18.32%。分析指出,5月迎来后疫情时期的消费小阳春,汽车数据继续攀升,这也是整个国内铝需求的市场最直观的反映。但也要看到5月份是前期消费受压制的集中释放,短
- 2
- |
- 25
- |
- 0
发布时间：2023-12-18 - 摘要：The effects of solution temperature on the microstructure and mechanical properties of 16-5 martensitic stainless steel were investigated by optical microscope（OM）,scanning electron microscope（SEM）,ThermoCalc,X-ray diffraction（XRD）,Rockwell hardness tester,universal material tensile tester,pendulum impact tester.The results reveal that the microstructure of the 16-5 martensitic stainless steel is composed of martensite and ferrite.With the solution temperature increasing,the amount of ferrite is increased,and tensile strength and elongation of the 16-5 martensitic stainless steel are increased firstly and then decreased,menahwile,impact energy of the stainless steel is decreased firstly and then increased.The tensile strength,elongation and impact energy reach the maximum values at 1 050℃,1 100℃,and 1 170℃,respectively.Ferrite can coordinate deformation and absorb shock load in martensitic stainless steel,however the increase of ferrite would play the role of seperating the matrix.关键词：Martensitic Stainless Steel;Solution Temperature;Microstructure;Mechanical Properties
- 2
- |
- 88
- |
- 0
发布时间：2023-12-18 - 摘要：The 6061 aluminum alloy and galvanized steel sheet were spot welded by using the DeltaSpot resistance spot welding machine produced by Fronius.The effects of different welding currents on the microstructure and mechanical properties of the joint were investiagted.The mechanism of the fracture behavior of the welded joint was described.The results reveal that the nugget diameter and the indentation rate of the spot welded joint are increased firstly and then stabilized with the increase of current.The intermetallic compound layer is grown sharply and then decreased with the increase of welding current,and the tensile shear strength of the joint is increased firstly and then decreased.When the welding current is 15.5 kA,the fracture surface of the joint presents mainly brittle fracture accompanied with plastic fracture.关键词：Resistance Spot Welding;Joint Structure;Intermetallic Compound;Fracture Morphology
- 3
- |
- 82
- |
- 0
发布时间：2023-12-18 - 摘要：High thermal conductivity Al-Si-Mg-Cu alloys were prepared by water-cooled copper mold.The microstructure,morphology and distribution of precipitated phases,hardness and thermal conductivity of the alloy were analyzed after solution and aging treatment.The evolution of microstructure and properties of the alloy during solution and aging treatment were analyzed.The results reveal that the alloy is mainly composed of primaryα-Al,eutectic Si phase,Mg2Si phase and iron-rich phases under as-cast state.After solution and aging treatment,the alloy phase composition presents the absence of change,however,morphology and distribution of precipitates change obviously.The eutectic Si phase is obviously spheroidized during the solution process with more uniform distribution after aging treatment,while Mg2Si and iron-rich phases have the smaller size and more uniform distribution after aging treatment.The solution and aging treatment have impact on morphology,size and distribution of the precipitated phase,which would reduce the probability of scattering during free electron transport,and build more channels for free electron transport in order to achieve the simultaneous optimization of the mechanical properties and thermal conductivity.Finally,the micro-hardness and the thermal conductivity of the alloy prepared reach 122.92 HV and 162.73 W/（m·K）,respectively.关键词：Al-Si Alloy;Solution and Aging Treatment;Microstructure;Thermal Conductivity
- 2
- |
- 74
- |
- 0
发布时间：2023-12-18 - 摘要：The influences of solid solution treatment on microstructure and mechanical properties of 2A14 aluminum alloy cold-rolled sheet were investigated by DSC,tensile testing,hardness testing and microstructure observation.The results reveal that the overheated temperature of 2A14 alloy cold rolled sheet is 508℃.With the increase of solid solution temperature and holding time,the degree of solid solution of the alloy is increased.After natural aging,the strength of 2A14 alloy sheet is gradually increased.With the solid solution treatment at 505℃ for 30 min,the strength of 2A14 alloy reaches the maximum value.However,with the further increase of the solid solution temperature,the recrystallization of alloy can be observed with the grain size coarsened,and the precipitation-strengthening is weakened,threrfore the strength of 2A14 alloy is reduced.In conclusion,the ideal solution treatment for 2A14 aluminum alloy sheet is heat presevation for 30 min at 505℃.关键词：2A14 Alloy;Solid Solution Treatment;Microstructure;Mechanical Properties
- 2
- |
- 97
- |
- 0
发布时间：2023-12-18 - 摘要：Ti-48Al-6Nb-xSi（x=0.5,1 and 2）TiAl alloy ingots with different silicon addition were prepared,and then heat treated at different temperature,respectively.The effects of heat treatment temperature on the structure and mechanical properties of the Ti-48Al-6Nb-xSi alloy ingots were analyzed.The results show that the structure of the as-cast ingots are refind after heat treatment and the equiaxed grain area inthe ingots is increased and the width of the column grains become smaller with the increasing of the heat treatment temperature.Meanwhile,the lamellar structure become thinner.The microstructure of the alloy is changed from column grain structure to equiaxed grain structure with increasing of heat treatment temperature.And the amount of Ti5Si3 phase is reduced,while its distribution become more uniform.The microhardness of Ti-48Al-6Nb-xSi alloys is increased with silicon content increasing and decreased with increasing of the heat treatment temperature.关键词：Heat Treatment;Titanium Aluminum Alloy;Structure;Microhardness
- 2
- |
- 101
- |
- 0
发布时间：2023-12-18 - 摘要：A triangular mesh generation algorithm based on the model of the STL file was proposed.By using divide and conquer,the model of the STL file was divided into multiple sub-regions,and the boundaries of the subregions were mapped to a two-dimensional plane to generate a mesh.The two-dimensional mesh was then mapped back to a three-dimensional surface.Finally,the sub-region meshes were stitched to generate a complete surface mesh.The nearest-neighbor search algorithm based on k-dtree was used to improve the reverse mapping process,which reduced the time complexity of reverse mapping and improved the overall mesh generation efficiency.The actual casting example shows that the mesh generated by the algorithm presents good quality.关键词：STL File;Surface Triangular Mesh;k-d Tree;Mesh Stitching;Mesh Reverse Mapping
- 2
- |
- 108
- |
- 0
发布时间：2023-12-18 - 摘要：The cracked Z-arm was tested by direct reading spectrometer,tensile tester,Brinell hardness tester and scanning electron microscope.The results show that the composition,structure and performance of Z-arm meet the technical requirements.The micro-morphology of the fracture presents cellular crystal,dendrite,pore and equiaxed dimple.The Z-arm is not fully fused in the casting process,resulting in the formation of cold shut,which is also the main reason of the cracking.Through the control measures of limiting pouring time,measuring pouring temperature and adding riser,effective improvement could be achieved.关键词：Crane;Z-arm;Cold Shut;ZG 35SiMn2MoV Steel;Cellular Crystal
- 2
- |
- 24
- |
- 0
发布时间：2023-12-18 - 摘要：The application background of silica based ceramic cores for hollow blade of turbine engine and the significance of high temperature strengthening of silica based ceramic cores were reviewed.The research status of high temperature performance strengthening effect of mineralization agent strengthening,hydrolysate strengthening and fiber strengthening on silica based ceramic cores was summarized,and the prospects for the future development of silica based ceramic cores were described.关键词：Hollow Blade;Silicon Based Ceramic Cores;Hydrolysate Enhancement
- 2
- |
- 171
- |
- 0
发布时间：2023-12-18 - 摘要：In order to realize the weight reduction of the hub and to avoid casting defects and reducing production costs,the low pressure die-casting process of the thin-walled spoke aluminum alloy hub with a minimum thickness of only 6 mm was subjected to finite element simulation.Based on the simulation results,the main casting parameters were determined such as the lifting pressure and injection speed,the preheating temperature of the mold,the pouring temperature of the molten metal and its flow rate,as well as the pressure and time during holding and solidification,and trial production was carried out.The test sample wheel with thin-walled spoke produced by the optimized parameters shows excellent comprehensive mechanical properties,and the three reliable performance test indexes meet the requirements of national standard.关键词：Thin-walled Spoke;Aluminum Alloy Wheel Hub;Low Pressure Casting;Finite Element Simulation;Performance Testing
- 2
- |
- 93
- |
- 1
发布时间：2023-12-18 - 摘要：As an important part of the hand generator,this main case is suitable to be produced through high-efficient die casting with the center-gate feeding method to produce high density castings.The main case casting that has working allowance at the secondary bearing housing and the rabbet along with an irregular contour can meet the precision requirements between the left housing and the internal and external rabbets of the right chassis,as well as between the bearing and the bearing housing after turning.关键词：Hand Generator;Housing;Die Casting
- 3
- |
- 39
- |
- 0
发布时间：2023-12-18 - 摘要：Aiming at the casting defects in low pressure casting aluminum alloy wheel hub,the characteristics and distribution of solidification defects were analyzed.The ProCAST software was used to simulate the filling and solidification process.The temperature distribution of the filling and solidification process of low pressure casting aluminum alloy wheel hub was presented,and the origination and mechanism of the solidification defects were analyzed.According to the simulated results,the cooling process of low pressure casting wheel hub was improved and optimized.The results reveal that by means of adding water-cooled pipes at the corresponding hot spot on the hub mould,it is determined that the cooling water is turned on 60 safter pouring to enhance the cooling rate of the hot spot and solidify the hubs in sequence,effectively reducing the shrinkage defects at the hot spot and ensuring the mechanical properties of the wheel hub.关键词：Low Pressure Casting;Aluminum Alloy Wheel;Numerical Simulation;Casting Defect
- 2
- |
- 185
- |
- 0
发布时间：2023-12-18 - 摘要：<正>据外媒报道,印度理工学院马德拉斯分校、北德克萨斯大学和美国陆军研究实验室的研究人员,共同开发了一种工程镁合金。这种合金的性能得到显著改善,可以替代钢和铝合金,用于汽车和航空零部件。据悉,这种新型工程合金强度高,延展性好,可在较高的应变速率下实现超塑性,从总体上减少制造时间、精力和成本;而且,此类合金很轻,有助于降低汽车的碳排放量,因
- 2
- |
- 58
- |
- 0
发布时间：2023-12-18 - 摘要：<正>近期,肯联铝业Constellium在官网宣布将领导一个汽车制造商和零部件供应商联盟,开发电动汽车用铝电池结构外壳。这项耗资1500万英镑的ALIVE（铝密集型车辆壳体Aluminium Intensive Vehicle Enclosures）项目,将在英国展开,项目的部分资金来自先进推进中心（APC）,并作为其低碳排放研究计划的一部分。肯联汽车结构与工业业务部门总裁Paul Warton说:"肯联很高兴与APC以及英国的汽车制造商和供应商合作,设计和制造
- 2
- |
- 19
- |
- 0
发布时间：2023-12-18 - 摘要：In investment casting production,castings with isolated hot spot are often encountered.In general,some problems can be solved by changing assemble-tree design or changing the structure design of castings.The kind of defect can also be eliminated or improved by changing pouring temperature and baking temperature.Some technological parameters affecting the surface burr of castings were presented in the experiment.After more than three years of production verification,the effect was satisfactory.关键词：Investment Casting;Isolated Hot Spot;Shrinkage Porosities（Holes）;Surface Burr
- 2
- |
- 86
- |
- 0
发布时间：2023-12-18 - 摘要：The shell structure of centrifugal pump is complex with nine external stiffeners and inside seven blades.The wax injection and casting process design are difficult problems in investment casting process.Numerical simulation and analysis were carried out on the wax injection process of centrifugal pump shell.The forming of wax pattern was realized by split wax pattern assembly.The flow field,isolated liquid phase region and shrinkage distribution of centrifugal pump shell were simulated and analyzed by the ProCAST software,and the casting process was optimized to improve the qualified rate of centrifugal pump shell.关键词：Investment Casting;Numerical Simulation;Wax Injection;Casting Process;Centrifugal Pump Shell
- 2
- |
- 77
- |
- 0
发布时间：2023-12-18 - 摘要：The selection of process parameters of lost foam casting has a very important influence on the mechanical properties of castings.L9（33）three-factor and three-level orthogonal test design was used to carry out the ZL102 alloy lost foam casting under the combination of different casting process parameters,and strength and elongation of aluminum-silicon alloy castings were taken as the evaluation index of mechanical properties.According to the grey correlation analysis method,the multi-objective process parameters were optimized to obtain the optimal process parameters of ZL102 alloy lost foam casting and the influence degree of each process parameter on the mechanical properties of the casting.The results show that with the modifier of 3.5%,the casting wall thickness of 5 mm and the pouring temperature of 760℃,the mechanical properties of ZL102 casting present desirable performance and the influence order of process parameters on the mechanical properties of casting is presented as follows:casting wall thickness>pouring temperature>modifier dosage.关键词：Grey Correlation Method;Lost Foam Casting;Mechanical Properties;Process Parameters
- 2
- |
- 42
- |
- 0
发布时间：2023-12-18 - 摘要：The effects of modification treatment with single additions and combined additions of rare earth elements Nd and Ce on the microstructure and properties of Al-20Si hypereutectic Al-Si alloy were investigated by SEM,micro-hardness tester and universal tensile machine.The results reveal that with Nd addition,primary Si size in the alloy is decreased firstly and then increased,so the tensile strength of the alloy is increased firstly and then decreased.With Ce content increasing,primary Si size is decreased slowly at first and then dramatically decreased,and tensile strength of the alloy is increased continuously.The primary Si size is not refined with compound addition of 0.4% Nd and 0.7% Ce,which is relative with the Nd inhibiting refinement of Ce on primary Si.With controlling Na addition at a fixed range and adding Ce over critical range,primary Si can be refined obviously.关键词：Hypereutectic Al-20Si Alloy;Nd;Ce;Primary Silicon
- 3
- |
- 38
- |
- 0
发布时间：2023-12-18 - 摘要：Thermecmast-Z thermal processing simulation machine was used to conduct thermal compression experiments on Ti60 alloy samples under the conditions of deformation temperature of 850～950 ℃,strain rate of 0.001～10 s-1 and true strain of 0.51,to obtain the measured flow curves of the alloy.The traditional friction correction model and the modified friction correction model were adopted to correct the measured flow curve,respectively.The results show that the friction effect has a significant influence on the flow stress of Ti60 alloy.Through un-even deformation of materials,the measured value of flow stress is higher than the true value.Compared with traditional friction correction,the flow curve corrected by modified-corrected friction can better reflect the dynamic response of the flow stress of Ti60 alloy to the true strain.With the increase of strain,the influence of friction effect on the flow stress becomes more significant.关键词：Ti60 Alloy;Flow Stress;Friction Correction
- 2
- |
- 51
- |
- 0
发布时间：2023-12-18 - 摘要：The effects of heat exposure treatment at 175℃for 50 hand 100 hon the microstructure and mechanical properties of T6-7A99 alloy were investigated by means of X-ray diffraction,transmission electron microscopy and room temperature tensile testing.The results reveal that the precipitate phases in the 7A99 alloy still consist ofη′andηphases after being exposured at 175℃for 50 hand 100 h.Theη′phases in the grains are transformed intoηphases at 175℃for 50 hand 100 hheat exposure treatment,meanwhile the size of precipitate phase is increased with the decrease of density of precipitate phases and the increase of PFZ width.The tensile strength,yield strength and elongation of 7A99 alloy treated by T6 reach 505 MPa,406 MPa and 12%,respectively,while those of ones exposured at 175℃for 50 hare 330 MPa,250 MPa and 16.8%,and those of T6-7A99 alloy exposured at 175℃for 100 hare 305 MPa,225 MPa and 20%,respectively.The mechanism is attributed to theηphases transformed fromη′phases reducing the distoration of the lattice severely.关键词：Heat Exposure Treatment;7A99 Aluminum Alloy;Mechanical Properties;Microstructure
- 2
- |
- 25
- |
- 1
发布时间：2023-12-18 - 摘要：The superplastic tensile tests of GH4169 alloy at different deformation processes were carried out to investigate the effects of deformation and heat treatment processes on the superplastic behavior of the material.The as-forged GH4169 alloy was annealed at 890℃×10 h+950℃×1 hand at 890℃×10 h+950℃×3 h.The observation of microstructure shows that the grain can be refined effectively by prolonging the second annealing time.The maximummvalue method was used for the superplastic tensile tests at different temperatures.The results show that the elongation of the alloy sample is desirable at 950℃.The elongation of the sample can be increased by prolonging the second annealing time.The strain induced superplasticity method based on the maximum m value method was used for the superplastic tensile test of the alloy.It can be seen that the elongation is the best after 20 min of pre-deformation and stretching time.And the forged GH4169 alloy has an elongation of566% under heat treatment at 890℃×10 h+950 ℃×3 h,which is significantly higher than that of the simple m-value method.关键词：GH4169 Alloy;Superplasticity;Strain Induced;δ Phase
- 2
- |
- 135
- |
- 0
发布时间：2023-12-18 - 摘要：WCx/CoCrCuFeNi1-x（x=0,0.1,0.2,0.3）high entropy alloy composite coatings were prepared on 304 stainless steel surface by electron beam cladding technology with different tungsten carbide（WC）content.The phase composition and microstructure of the composite coatings with different WC content were investigated by using X-ray diffraction（XRD）and scanning electron microscopy（SEM）.The surface hardness of the composite coatings was measured by vickers hardness micrometer.The results show that the high-entropy alloy coatings with different WC content are composed of simple face-centered cubic structure（FCC）phase,and with the increase of WC content,the intensity of diffraction peak of FCC phase is gradually weakened,and the position of diffraction peak is also gradually shifted to a lower angle.When WC is absent in the coating,the coating structure is mainly composed of equiaxed crystals.When WC is added,a small number of columnar crystals appear in the middle and bottom position of the coating.Compared with laser cladding and arc melting,element segregation can be effectively inhibited by high-energy electron beam with the high cooling rate,so the degree of segregation in the coating is relieved.With the increase of WC content,cracks in the coating is decreased gradually,while the hardness is increased firstly and then decreased.关键词：Electron-beam Cladding;High Entropy Alloy Coating;Microstructure;WC Content
- 2
- |
- 175
- |
- 0
发布时间：2023-12-18 - 摘要：Graphene/aluminum-lithium matrix composites were prepared by wet milling and hot isostatic pressing process,and then the hot deformation behavior of graphene/aluminum-lithium matrix composites was investigated by Gleeble-3500 thermal simulation machine at deformation temperature in range of 400～430 ℃and strain rate in range of 0.001～10 s-1.The results reveal that stress-strain curves are presented as strain soften behavior,where with increasing in strain rate and decreasing in deformation temperature,the flow stress is increased.Based on the Arrhenius equation,the hot deformation activation energy Q was calculated as 222.15 kJ/mol,and the hot deformation constitutive equation was established.关键词：Graphene/Aluminum-Lithium Matrix Composite;Hot Deformation Behavior;Flow Stress Constitutive Equation
- 2
- |
- 73
- |
- 0
发布时间：2023-12-18 - 摘要：The microscopic damage and macroscopic mechanical behavior of Cf/Al composites with different fiber content were investigated by micromechanical and experimental method.Representative Volume Element（RVE）with diagonal regular quadrilateral and regular hexagonal fiber arrangements were established according to the composites microstructure.The damage behavior of matrix alloy was described by ductile damage model and the fiber fracture behavior was simulated using a maximum stress failure criterion.And then a micromechanical finite element model based on cohesive interface was established and the calculation reliability was verified by the experimental results.Based on the micromechanical model,the damage evolution and fracture behavior of the composites with different fiber content were analyzed.It is found that the micromechanical model with regular hexagonal fiber arrangement can predict the elastoplastic behavior of composites accurately.At the first stage,the initial interface damage is accumulated with the increase of strain and induce some local interface failure.At the middle stage,some local matrix damage is initialed and developed near the failed interface.At the last stage,the interface and matrix failure results in the transverse cracking of the composites.The tensile fracture surface exhibits the characteristic of interfacial debonding and matrix tearing.The transverse tensile modulus and ultimate strength of the composite are decreased with the increase of fiber content,which can be attributed to the occurrence of more interface quantity and interface area.关键词：Cf/Al Composites;Micromechanics;Damage Evolution;Fiber Content;Mechanical Properties
- 2
- |
- 146
- |
- 0
发布时间：2023-12-18 - 摘要：The effects of three different cold rolling methods on the microstructure and mechanical properties of aged Cu-1Cr-0.15Zr alloy were investigated.The results show that low temperature rolling can improve the hardness of the aged Cu-1Cr-0.15Zr alloy,and the hardness and electric conductivity of the aged Cu-1Cr-0.15Zr alloy will be further improved after the intermediate aging treatment.The tensile strength of the low temperature rolled and intermediate aged samples is higher than that of the ambient rolled and low temperature rolled samples,and the electric conductivity of the peak aged with low temperature and intermediate aged samples has the highest value.The wear volume of the samples of room temperature rolling,low temperature rolling and low temperature+intermediate aging is 0.682,0.191 and 0.054 mm3,respectively.The wear resistance of the samples of low temperature+intermediate aging after aging present desirable.The tensile strength and wear resistance of the samples of low temperature+intermediate aging after aging are higher than those of the samples at room temperature rolling and low temperature rolling,which is mainly attributed to the small distance between twin/matrix layers in the alloy and more fine core-shell like Cr rich phases with dispersion strengthening effect.关键词：Cu-1Cr-0.15Zr Alloy;Cold Rolling Method;Aging;Mechanical Properties;Conductivity
- 2
- |
- 79
- |
- 0
发布时间：2023-12-18
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0