自润滑烧结镁基复合材料的拉伸、压缩和磨损行为（英文）

采用粉末冶金方法制备石墨/二硫化钼增强镁基自润滑复合材料,并分别表征这些复合材料的显微组织、物理性能、力学性能和磨损性能。利用XRD手段鉴定复合材料中的Gr/MoS_2相。显微组织观察表明,Gr/MoS_2颗粒均匀地分散在镁基体中。在室温条件下施加载荷5 g并保持15 s,测试复合材料的显微硬度,得到所有复合材料的显微硬度为VHN 29-34。使用显微硬度、拉伸和压缩试验研究材料的力学性能,并用扫描电子显微镜分析材料的断口形貌,得到Mg-10MoS_2复合材料最高的硬度、抗压强度和拉伸强度。用销-盘式摩擦仪测试烧结复合材料的摩擦因数和磨损量。另外,通过磨损表面特征,利用SEM系统分析复合材料的摩擦磨损机制。结果表明,与石墨相比,二硫化钼的摩擦因数和磨损有所减少。

纳米银对铸态6061铝合金的组织、力学和摩擦性能的影响（英文）

利用搅拌铸造法制备不同含量纳米银(1%,2%)6061铝基合金,采用硬度、拉伸、压缩和磨损实验表征所制备的试样,并用布氏硬度试验机测试样品的室温硬度。随着合金化元素质量分数的增加,硬度明显增大。采用光学显微镜检测抛光样品,通过扫描电子显微镜进一步研究拉伸和压缩试件的断裂表面。与基体合金相比,铝-银合金的抗压强度、极限抗拉强度、伸长率和耐磨性有所提高。采用搅拌铸造技术得到了相对均匀和精细的组织,提高了熔融金属中增强材料的添加量。结果表明,最佳硬度组合6061铝-纳米银合金可取代传统材料,获得更优的性能和较长的寿命。

Rietveld refinement of powder X-ray diffraction,microstructural and mechanical studies of magnesium matrix composites processed by high energy ball milling

This research reports the processing of magnesium matrix composites reinforced with silicon carbide(SiC)and aluminium oxide(Al_(2)O_(3))using powder metallurgy technique through high energy milling.Samples of Mg-SiC and Mg-Al_(2)O_(3)composites subjected to high energy ball milling for different vol%of secondary particles 20,30 and 40%of SiC and Al_(2)O_(3)are studied by X-Ray diffraction technique.The rietveld method as implemented in the Fullprof program is applied in order to determine the quantities of the resulting crystalline phases and amorphous phases at each stage of the mechanical treatment.Microstructural examination is carried out using Scanning Electron Microscope(SEM).In addition,crystal structural analysis using appropriate size and strain models is performed in order to handle the distinctive anistrophy that is observed in convinced crystallographic directions for the magnesium composite.The results are furnished in terms of crystalline domains size enlargement of the magnesium composites phases upon prolonged milling duration and discussed in the light of up to date views and theories on crystal growth of nanocrystaline materials.The hardness of the composite samples is calculated by Vickers’s Hardness tester.Further,dry sling wear test and corrosion test are performed for the fabricated composites.Composite with 30%secondary particles incorporated magnesium composites exhibits better wear and corrosion resistance than the other composites.