轴承用耐磨Al-Sn-Cu合金的显微组织与性能

Microstructure and properties of wear resistant Al-Sn-Cu bearing alloy

采用直接水冷铸造法制备Al-Sn-Cu合金,通过室温力学性能测试、摩擦磨损试验、金相显微分析(OM)、扫描电镜分析(SEM)、X射线衍射分析(XRD)、透射电镜分析(TEM)等手段对合金不同状态下的力学性能、摩擦磨损性能、显微组织结构及其演变规律进行研究。结果表明:经过(480℃,19 h)均匀化处理,合金组织中呈连续网状分布的β(Sn)消失,变成球状和块状依附或者围绕在Al_2Cu周围;挤压变形之后,β(Sn)和Al_2Cu被拉长破碎并得到细化,组织得到改善。合金适宜的固溶-时效制度为(490℃,1 h)固溶、水淬后(190℃,4 h)时效,在此状态下,晶内出现弥散分布的Al_2Cu析出相和纳米级尺寸的β(Sn),合金的抗拉强度、屈服强度、伸长率、摩擦因数和磨痕宽度分别为318 MPa、252 MPa、10.5%、0.1053和1446.49μm,具有良好的力学性能和摩擦磨损性能。

The Al-Sn-Cu alloy was prepared by direct water-cooling casting.The mechanical properties,wear properties,microstructure and evolvement rule of alloy were investigated by means of room temperature tensile test,wear test,OM,SEM,XRD and TEM.The results show that the continuous webbed β（Sn） disappears,and Al2Cu phases are attached or enveloped by globular and nubbly β（Sn） phases after homogenization treatment（480℃,19 h）.The β（Sn） and Al2Cu phases are elongated and broken after extrusion,which results in the fine microstructure of alloy.The suitable solution and aging treatment of alloy is solution treated at 490℃ for 1 h,water-quenched and then aged at 190℃ for 4 h.The ultimate tensile strength,yield strength,elongation,friction coefficient and wear width of alloy are 318 MPa,252 MPa,10.5%,0.1053 and 1446.49 μm,respectively,after the suitable solution and aging treatment.At the same time,Al2Cu precipitated phases and nano-sized β（Sn） dispersively distribute in the crystal,which leads to the fine mechanical properties and wear properties of alloy.