Forging of Metal-Matrix Composites -An Experimental and Analytic Approach to Process Design.

摘要

The large-scale plastic deformation behavior of aluminum-stainless steel fiber composites was examined under conditions of simulated forging. With the load applied perpendicular to the direction of reinforcement,deformation occurs in a plane strain mode with no metal flow in the direction of fiber alignment. Two possible types of material damage are identified: (1) void formation in the matrix adjacent to the fibers and inter-fiber cracking of the matrix; (2) breaking of the fibers,leading to deviations from plane strain deformation. Forming limit criteria for both types of damage were established in terms of the normal and lateral pressures in the material. These pressures are related to the workpiece geometry and friction parameters of the system through plasticity theory. Thus,the forming limit criteria,in conjunction with plasticity theory,form the basis of a rational approach to design of processes for forging complex shapes from fiber-reinforced composite materials having a ductile matrix. (Author)