50 巻 (2009) 582 号 p. 645-649
A cold repeated forming process of compacts for producing metal form was developed to strongly bond powder particles. In this process, the compact undergoes severe deformation for the strong bonding of particles by repeated backward extrusion and cup compression, and thus the compact largely foams owing to the accumulation of foaming gas inside the compact during heating. The cold repeated forming process without heating is much simpler than that for the conventional hot extrusion. The relative density of the foam was decreased by adding silicon powder to the compact, and an aluminum foam having a relative density of 0.27 was obtained using 2 repeats of backward extrusion and cup compression, 1.5 mass% titanium hydride powder and 4 mass% titanium silicon powder. In addition, one-piece foam was successively produced from the bonding of two compacts during the foaming in a die. It was found that the cold repeated forming of compacts is effective for the production of metal foam.