Xu Bingqian, Sun Jiapeng, Yang Zhenquan, Han Jing, Song Dan, Jiang Jinghua, Ma Aibin
College of Mechanics and Materials, Hohai University, Nanjing 210098, China.
School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou, 221116 Jiangsu Province, China.
Scanning. 2020 Jul 8;2020:4873286. doi: 10.1155/2020/4873286. eCollection 2020.
The microstructure design based on the development of heterostructure provides a new way for high strength and ductility Mg alloys. However, the wear property, as an important service performance, of Mg alloys with heterostructure is scarcely investigated. In this work, a high strength and ductility AZ91 Mg alloy with multiheterostructure was prepared a processing route combined industrial-scale equal channel angular pressing (ECAP) and aging. The multiheterostructure consists of the heterogeneous grain structure and heterogeneous precipitates. The dry sliding wear behavior of this multiheterostructured (MH) alloy is investigated compared to the as-cast alloy. The impacts of the applied load and duration time on the wear volume and coefficient of friction (COF) are analyzed, and the wear mechanism is further discussed. The result indicates that although the MH alloy exhibits high-desirable strength-ductility synergy, it shows a poorer wear resistance but a relatively lower COF compared to the as-cast alloy at the present condition. The wear mechanism of both alloys mainly involves abrasive wear, as well as mild adhesion, delamination, and oxidation. In comparison, the MH alloy shows relatively severe adhesion, delamination, and oxidation. The poor wear resistance of the MH alloy at the present dry sliding wear condition is linked to the abundant grain boundaries and fine precipitates. Therefore, one should reasonably use the MH Mg alloy considering the service conditions to seek advantages and avoid disadvantages.
基于异质结构发展的微观结构设计为高强度和高延展性的镁合金提供了一条新途径。然而，作为一项重要服役性能的异质结构镁合金的磨损性能却鲜有研究。在本工作中，通过一种将工业规模等径角挤压（ECAP）与时效相结合的加工路线制备了一种具有多异质结构的高强度和高延展性AZ91镁合金。该多异质结构由异质晶粒结构和异质析出相组成。将这种多异质结构（MH）合金与铸态合金相比，研究了其干滑动磨损行为。分析了外加负载和持续时间对磨损体积和摩擦系数（COF）的影响，并进一步探讨了磨损机制。结果表明，尽管MH合金表现出高度理想的强度 - 延展性协同效应，但在当前条件下，与铸态合金相比，其耐磨性较差，但摩擦系数相对较低。两种合金的磨损机制主要涉及磨粒磨损，以及轻微粘着、分层和氧化。相比之下，MH合金表现出相对严重的粘着、分层和氧化。在当前干滑动磨损条件下，MH合金耐磨性差与丰富的晶界和细小析出相有关。因此，考虑服役条件合理使用MH镁合金才能扬长避短。
