Al-7Sn-1.1Ni-Cu-0.2Ti轴承合金微观组织与力学性能

发布时间：2018-03-03 00:38

  本文选题：轴承合金　切入点：微观组织　出处：《材料工程》2017年06期 　论文类型：期刊论文

【摘要】：采用扫描电镜、能谱分析、金相显微镜与WDW-100KN万能拉伸试验机研究Al-7Sn-1.1Ni-Cu-0.2Ti轴承合金的微观组织与力学性能,结合盘-销式摩擦磨损试验机考察合金不同组织状态的润滑性能。结果表明:Al-7Sn-1.1Ni-Cu-0.2Ti合金凝固收缩率为1.13%,铸态抗拉强度、屈服强度、伸长率与布氏硬度分别为191,147MPa,15.6%与34.6HBS,随着低温时效与退火热处理过程的进行,抗拉强度略有上升,屈服强度保持不变,伸长率与布氏硬度均呈现出先上升后下降的变化趋势;沿晶界分布的共晶Sn相形貌受界面张力作用逐步由板片状与骨骼状转变为层片状与短棒状,部分吸热脱溶析出在晶界处形成空腔结构,初生α-Al基体平均晶粒尺寸为182μm。与铸态和340℃退火6h相比,经175℃时效10h后,摩擦因数降低了28.6%与78.6%,体积磨损量减少了157.1%与471.4%,断口形貌以沿晶断裂与韧窝断裂为主。
[Abstract]:The microstructure and mechanical properties of Al-7Sn-1.1Ni-Cu-0.2Ti bearing alloy were studied by SEM, EDS, metallographic microscope and WDW-100KN universal tensile tester. The lubrication properties of the alloy in different microstructure states were investigated by using a disk-pin friction and wear tester. The results showed that the solidification shrinkage rate of the alloy was 1.13. The as-cast tensile strength and yield strength were obtained. The elongation and hardness of Brinell were 191t 147MPA 15.6% and 34.6HBSrespectively. With the process of low temperature aging and annealing heat treatment, the tensile strength increased slightly, the yield strength remained unchanged, and the elongation and Brinell hardness showed a trend of first rising and then decreasing. The morphology of eutectic Sn phase distributed along grain boundary is gradually changed from lamellar and skeletal to lamellar and short rod by interfacial tension, and some endothermic desolvent precipitates form cavity structure at grain boundary. The average grain size of primary 伪 -Al matrix is 182 渭 m. Compared with as-cast and annealed at 340 鈩，

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