Experimental Studies of a Rectangular Cup Formation of Al 7075 Alloy in Superplastic Forming Process

Abstract

AbstractSuperplastic behaviour of certain metals and alloys having very fine grains, very large tensile elongations are obtained within certain temperature ranges at low strain rates. In this work, Al-alloy superplastic sheet material was considered. The AA 7075 sheets were subjected to the modified thermomechanical treatment, to obtain the average grain size of 10μm in less processing time. These alloys can be formed into complex shapes by superplastic forming, a process that employs common metalworking techniques. This paper aims to study the formability, thickness distribution, cavitation effect and microstructure feature for aluminium material by considering variable parameters such as forming pressure from 0.2 MPa, 0.3 MPa and 0.4 MPa and the sheet thickness of 2 and 1.5 mm. The 2 mm sheet gives better results of 0.4 MPa for both high thinning factor of 0.9466 and less cavity volume fraction of 4.4%