Studies on Press-forming of Aluminum Alloys in the Coexisting State of Liquid and Solid : 3rd Report, Mechanical Properties of Injection-formed Aluminum Alloys

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.