关键词: 等效应力, 等效应变, 显微硬度, 加工硬化模型

Abstract:

A new flow control forming(FCF) of sheet metal process for parts with step cross-section was performed using aluminum sheet materials. The equivalent stress and strain distribution were obtained through deforming simulation of parts during pressing and cold forging multiple processes using DEFORM through finite element analysis. The work-hardening characterization of parts was analyzed through measuring the hardness of part surfaces after forming. Experimental results indicate that the work-hardening effect of parts with step cross-section including triplex processes (blanking, extrusion and coining), is higher than that of parts with sole pressing or cold forging. The hardness in the low surface of parts is higher with the range of 5%~10% than that in the upper surface of parts. The hardening effects of parts in both low and upper surfaces will be weakening gradually within 0~1.4t (t represents thickness), with radial direction starting from inner hole or outer edge. One new work-hardening model was suggested. 

Key words: equivalent stress, equivalent strain;micro hardness, work-hardening model