工业纯铝等通道球形转角膨胀挤压变形的力学与摩擦学性能

对传统等通道转角挤压工艺(equal channel angular extrusion,ECAE)进行改进,提出一种新型剧烈塑性变形法(severe plastic deformation,SPD)——等通道球形转角膨胀挤压(equal channel angular expansion extrusion with...

Mechanical and Tribological Properties of Commercially Pure Aluminum Processed by Equal Channel Angular Expansion Extrusion with Spherical Cavity

A novel severe plastic deformation (SPD) method, entitled Equal Channel Angular Expansion Extrusion with Spherical Cavity (ECAEE-SC) was introduced based on a modification of the conventional Equal Channel Angular Extrusion (ECAE) process. By integrating expansion, shear and extrusion deformations in a single extrusion pass, ECAEE-SC process could induce larger accumulated strains into the billet, resulting in the significant grain refinement and the associated properties improvement. In the present study, commercially pure aluminum (Al-1060) was subjected to one pass of ECAEE-SC process at room temperature, and two passes of ECAE process were also conducted for comparison. The microstructure, Vickers hardness, tensile properties and wear properties of processed material were investigated. The results showed that after one pass of ECAEE-SC process, the grains of ECAEE-SC processed aluminum were greatly refined with a typically elongated microstructure due to the high level of strains induced in the material. The hardness and tensile strength of ECAEE-SC processed material were increased with a significantly growth almost 92.6% and 91.8% than the initial material, respectively. These improvements were considerately higher than that achieved by two passes of ECAE process. Moreover, the wear resistance of ECAEE-SC processed material was also enhanced. The worn surface morphology of ECAEE-SC processed sample represented the minimum width and depth of the wear scars, indicating that the wear mechanism could be dominated by abrasive wear.