Wear Behavior of the Multiheterostructured AZ91 Mg Alloy Prepared by ECAP and Aging

Abstract

<jats:p>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 <jats:italic>via</jats:italic> 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.</jats:p>

Microstructure and Mechanical Properties of Gradient Nanostructured Q345 Steel Prepared by Ultrasonic Severe Surface Rolling

“…The GNS surface layer also involves a high density of dislocations (Figures 3 – 5 ), which also contributes to strength improvement by obstructing dislocation motion. As a type of heterostructured material [ 30 , 31 ], GNSs can induce an HDI-strengthening effect through mechanical incompatibility. The GNS also provides extra work hardening capacity, i.e., HDI hardening, which is regarded as the primary source origin of high ductility [ 32 ].…”

Mechanical and wear behavior of room-temperature ECAPed Mg-4Li alloy

“…shows the SEM micrographs of worn surfaces of annealed and ECAPed samples. Numerous studies 19,23,[54][55][56][57][58][59][60][61][62] have classified the various wear mechanisms in magnesium alloys into two basic categories of wear regimes namely, mild and severe wear regimes, based on the wear test parameters, that is, applied load and sliding velocity. In the mild wear regime exists two subregimes denoted by oxidation wear and delamination wear regime.…”

Heterostructured Materials by Severe Plastic Deformation: Overview and Perspectives

“…100) Low-temperature heat-treatments are another option to promote the formation of precipitates in the ECAPprocessed material, i.e., multiphasic materials. 99,[101][102][103] The aforementioned HSMs produced by ECAP have shown a lower strength-ductility trade-off compared to their homogeneous counterparts. 94,[99][100][101][102] Regarding physical properties, some works have focused on improving the electrochemical behavior of ECAPprocessed HSMs compared with their homogeneous counterparts.…”