Characterisation of Conform™ and conventionally extruded Al–4Mg–1Zr. Effect of extrusion route on superplasticity

Continuous extrusion (Conform™) is a well-established technique for the production of profiles from both solid and particulate feed stock. To the first approximation it is considered to be analogous to conventional extrusion, although there are significant differences in the metal flow during both processes. Metal flow during conventional extrusion is characterised by relatively low redundant work, whereas the Conform™ process requires significant redundant work to be successful. Most of the available scientific literature to date is concerned with the simulation of the Conform™ process and not its effect on the resultant microstructure of the product. In this paper, a detailed comparison of the microstructure, texture and superplastic properties developed during Conform™ and conventional extrusion for a particulate Al–4Mg–1Zr alloy are presented.