AZ系镁合金的轻微-严重磨损转变研究  

Investigation on the Mild to Severe Wear Transition for AZ System Magnesium Alloys

作　　者：安冬琪 肖宏伟[1] 李东成[2] 文子[3] 

机构地区：[1]吉林大学汽车工程学院,长春130025 [2]吉林大学辊锻工艺研究所,长春130025 [3]吉林大学汽车材料教育部重点实验室,长春130025

出　　处：《机械工程学报》2016年第6期79-85,共7页Journal of Mechanical Engineering

基　　金：教育部博士点基金资助项目(20110061110031)

摘　　要：为研究AZ系镁合金的轻微-严重磨损转变机制,在0.1~4.0 m/s的滑动速度范围内对AZ31和AZ51镁合金进行干摩擦试验。研究不同滑动速度下载荷对磨损率、磨损机制的影响,绘制磨损转变图,分析磨损亚表层组织与性能变化。结果表明：轻微磨损区的磨损机制主要包括氧化、磨粒和剥层磨损,严重磨损区的磨损机制则为严重塑性变形和表面熔化;在轻微-严重磨损转变前后,亚表层经历塑性变形-再结晶的组织转变和应变强化-再结晶软化的性能变化,磨损表层发生再结晶软化是导致轻微-严重磨损转变的主要机制,据此建立判定轻微-严重磨损转变的表面临界再结晶温度准则,利用再结晶动力学计算不同滑动速度下的表面临界再结晶温度和转变载荷。In order to clarify the reason behind the mild to severe wear transition for AZ system alloys, dry sliding wear tests are performed on AZ31 and AZ51 alloys within a sliding speed range of 0.1-4.0 m/s. Effects of load and sliding speed on wear rate and wear mechanism are investigated, wear transition maps are established, changes in subsurface microstructure and mechanical property are analyzed. Results show that oxidation, abrasion and delamination operate in the mild wear regime, severe plastic deformation and surface melting prevail in the severe wear regime. Subsurface material experiences the plastically deformed to dynamic recrystallization（DRX） microstructural transformation and the strain hardening to DRX softening transformation. The mild to severe wear transition is determined by realization of DRX in subsurfaces of AZ system magnesium alloys, and a criterion is established using DRX dynamics for prediction of critical DRX temperatures and transition loads at different sliding speeds.

关 键 词：镁合金 磨损机制 显微组织 力学性能 

分 类 号：TH117[机械工程—机械设计及理论]