Molding of Aluminum Foams by Using Hot Powder Extrusion

Abstract

In order to form aluminum foams directly from powder, a combined process of hot powder extrusion and molding is proposed. Aluminum powder mixed with a foaming agent is extruded into the mold through the die heated to a temperature higher than the melting point, and the mold is filled with the aluminum foam. When a stainless steel pipe is used for a simple mold, an aluminum foam bar is obtained of which the relative density varies between 0.2 and 0.3. The molding of aluminum foam by using three types of mold shape shows the influence of gravity and friction. The effect of gravity is significant when a large step exists at the connection between the mold inlet and the die outlet, and friction is dominant in cases where foam is mold in a narrow space.

Keywords

• porous metals
• aluminum foam
• hot powder extrusion
• molding
• density
• gravity
• friction