DEVELOPMENT OF FRICTION-ASSISTED EXTRUSION PROCESS FOR PRODUCING THINMETAL STRIPS

A new concept of ''friction-assisted extrusion'' to produce a thin met al strip was proposed. In this process, a rectangular prismatic workpi ece inserted into the container is compressed by a punch against an an vil, and the anvil is forced to move horizontally. A thin strip can be extruded through the gap by exerting a high friction force over the a nvil surface. Very thin strips of aliminum up to about 15 mu m in thic kness could be formed up to the extrusion ratio R=667 with a considera bly low punch pressure ratio p/2k=1 similar to 2 (p : punch pressure, k: yield shear stress), which agreed with the theoretical value estima ted by the upper bound approach analysis. The friction-assisted extrus ion process was applied to a forming of thin strips from aluminum powd er. The thin strips formed from the aluminum powder have superior mech anical properties to those formed from bulk aluminum materials.