Abstract:According to the bimetal (Cu & Al) extrusion process, the interface deformation characteristics of Cu & Al have been analyzed by using rigid plastic finite element method (FEM) with the frictional elements inserted between two contacting metals. The finite element equations considering the frictional element have been obtained. The bimetal flow patterns under different interface friction coefficients and yield stress ratios are given. Also, the influences of the interface friction coefficients and the yield stress ratio between two contacting metals on the interface variation and forming process have been discussed.

Key words: bimetal forming　interface deformation characteristics　frictional element