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 via 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.

中文翻译：

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ECAP和时效制备多异质结构AZ91镁合金的磨损行为

基于异质结构发展的显微组织设计为高强延展镁合金提供了一条新途径。然而，具有异质结构的镁合金的磨损性能作为重要的使用性能却很少被研究。在这项工作中，通过结合工业规模等通道角挤压 (ECAP) 和时效的加工路线制备了具有多异质结构的高强度和延展性 AZ91 镁合金。多异质结构由异质晶粒结构和异质沉淀组成。与铸态合金相比，研究了这种多异质结构 (MH) 合金的干滑动磨损行为。分析了施加的载荷和持续时间对磨损量和摩擦系数（COF）的影响，并进一步讨论了磨损机制。结果表明，尽管 MH 合金表现出理想的强度-塑性协同作用，但与目前条件下的铸态合金相比，它的耐磨性较差，但 COF 相对较低。两种合金的磨损机制主要涉及磨粒磨损，以及轻度粘附、分层和氧化。相比之下，MH 合金表现出相对严重的粘附、分层和氧化。MH合金在目前干滑动磨损条件下的耐磨性差与丰富的晶界和细小的析出物有关。因此，应考虑使用条件，合理使用MH镁合金，扬长避短。与目前条件下的铸态合金相比，它显示出较差的耐磨性，但具有相对较低的 COF。两种合金的磨损机制主要涉及磨粒磨损，以及轻度粘附、分层和氧化。相比之下，MH 合金表现出相对严重的粘附、分层和氧化。MH合金在目前干滑动磨损条件下的耐磨性差与丰富的晶界和细小的析出物有关。因此，应考虑使用条件，合理使用MH镁合金，扬长避短。与目前条件下的铸态合金相比，它显示出较差的耐磨性，但具有相对较低的 COF。两种合金的磨损机制主要涉及磨粒磨损，以及轻度粘附、分层和氧化。相比之下，MH 合金表现出相对严重的粘附、分层和氧化。MH合金在目前干滑动磨损条件下的耐磨性差与丰富的晶界和细小的析出物有关。因此，应考虑使用条件，合理使用MH镁合金，扬长避短。MH合金在目前干滑动磨损条件下的耐磨性差与丰富的晶界和细小的析出物有关。因此，应考虑使用条件，合理使用MH镁合金，扬长避短。MH合金在目前干滑动磨损条件下的耐磨性差与丰富的晶界和细小的析出物有关。因此，应考虑使用条件，合理使用MH镁合金，扬长避短。