Studies on Press-Forming of Aluminum Alloys under Coexisting State of Liquid and Solid. : 1st Report, Mechanical Properties of Press-Formed Aluminum Alloys.

Abstract

In order to collect the fundamental data about the press-forming under half-melting of Al-4.5%Cu alloys and Al-4%Cu alloys containing Mg, investigation has been made on influence of pressure, billet temperature and die temperature on the mechanical properties of the products. The results are as follows. The tensile strength and the tensile elongation of the products pressed under 1030 kg/cm² are remarkably large as compared with those under no pressure. This might be explained by the decrease of intermetallic compound Al₂Cu and the yield of a sub-boundary. As to billet temperature, the tensile strength and the tensile elongation become the highest at midpoint between the liquidus line and the solidus line. It may be caused by a dendritic structure remaining in the product when the temperature is lower than the middle temperature, and by a precipitation of granular Al₂Cu and the decrease of copper solubility in the center of the grain when the temperature is higher.