关键词: 滑移线场, 挤压变形, 金属基复合材料, 晶须形貌

Abstract: To analyze the effect of extrusion deformation on whiskers morphology of SiCw/6061 composites, the extrusion processes of SiCw/6061 composites are investigated based on the theory of slip-line field. By presenting the characteristics of the slip-line field and the hodograph of forward extruded solid parts and backward extruded cup-shaped parts of typical extrusion process, the effects of the slip-line field and the velocity discontinuity on the morphology of SiC whiskers are discussed. Furthermore, the results are contrasted with the scanning electron microscope photos of whiskers morphology obtained from experiments. The research results indicate that the maximum shear stress induces the rotation of whiskers along the tangential direction of the slip line, and the final directions of whiskers are the resultants of the original directions of whiskers and the tangential directions of the slip line. In addition, the severe velocity change corresponding to the velocity discontinuity between the different sides of the slip line induces the rupture of whiskers.

Key words: Extrusion deformation, Metal matrix composites, Slip-lines field, Whisker morphology