Exploration of equal channel angular pressing routes for efficiently achieving ultrafine microstructure in magnesium

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:733

Article

Li, Qizhen^1,2  Jiao, Xing² 

[1] Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA

[2] Univ Nevada, Dept Chem & Mat Engn, Reno, NV 89557 USA

关键词: Severe plastic deformation;    Equal channel angular pressing;    Heterogeneous microstructure;    Grain refinement;    Twinning and detwinning;   

DOI  :  10.1016/j.msea.2018.07.041

来源: Elsevier

【 摘 要 】

This research explored the equal channel angular pressing (ECAP) routes for efficient microstructure refinement of pure magnesium. The samples were processed for a series of numbers of ECAP passes through three different routes (i.e. A, Bc, and C routes). The utilized ECAP mold had a large channel angle of 142 degrees and the processing temperature was 200 degrees C. The microstructure and texture of the processed samples were characterized using optical microscope and x-ray diffraction technique. The results show that tension twinning deformation mechanism during an ECAP pass led to the formation of profuse twins in magnesium and the twinning/detwinning dominated microstructure refinement mechanisms. After 8 ECAP passes, both Bc and C routes reduced the length and width of twins to similar to 13 mu m and similar to 3 mu m respectively. Bc and C routes can refine the microstructure of magnesium more efficiently than A route. Among the three studied routes, Bc route achieved the most homogeneous microstructure with uniformly distributed twins, while both A and C routes resulted in heterogeneous microstructure.

【 授权许可】

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