EFFECTS OF DIRECT EXTRUSION PROCESS ON MICROSTRUCTURE, TEXTURE EVOLUTION AND YIELD STRENGTH OF MAGNESIUM ALLOY AZ31

摘要

Direct extrusions of commercial casting AZ31 alloy were carriedout at elevated temperatures with different extrusion velocities.Microstructure and texture distribution of extruded rods wereinvestigated with optical microscopy (OM) and electronbackscattered diffraction (EBSD). Tensile tests were conducted atroom temperature using samples from both casting billets andextruded rods. The experimental yield strength can not be solelydescribed by average grain size. In this paper, the grain size andorientation in the extruded samples were characterized by EBSD,and Hall-Petch equation was applied to each individual grain withthe input from EBSD results (individual grain size andorientation). The yield strength of tensile sample (polycrystallineaggregate) and individual grain was related by Taylor assumption.The predicted yield strength showed the same trend as experimentresults.