Improvement of die filling by prevention of temperature drop in gas forming of aluminium alloy tube using air filled into sealed tube and resistance heating

摘要

A gas forming process of an aluminium alloy tube using air filled into a sealed tube and resistance heating was developed. In this process, the sealed tube is bulged by resistance heating without controlling internal pressure. The deformation behaviour of the tube inside the die was observed through a heatproof glass plate attached to the side wall of the die. The temperature drop of the tube during forming was prevented to improve the die filling by a ceramic die with a small thermal conductivity and optimisation of the current density path.