FEM SIMULATION OF A FRICTION TESTING METHOD BASED ON COMBINED FORWARDCONICAL CAN-BACKWARD STRAIGHT CAN EXTRUSION

A new friction testing method based on combined forward conical can-ba ckward straight can extrusion is proposed in order to evaluate frictio n characteristics in severe metal forming operations. By this method t he friction coefficient along the conical punch surface is determined knowing the friction coefficient along the die wall. The latter is det ermined by a combined forward and backward can extrusion of straight c ans. Calibration curves determining the relationship between punch tra vel, can heights, and friction coefficient for the two rests are calcu lated based on a rigid-plastic FEM analysis. Experimental friction tes ts are carried out in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confir m that the theoretical analysis results irt reasonable values for the friction coefficient.