Influence of initial extruded microstructures of Al-4.4Zn-1.4Mg alloy flat bar on VDA bendability

Abstract

The bendability of extruded Al-4.4Zn-1.4Mg (mass%) alloy flat bars with 1.4 mm thickness having two types of microstructures which are fibrous and recrystallized is evaluated by a Verband der Automobilindustrie (VDA) bending test without pre-strain. The recrystallized specimen has better bendability than the fibrous one. The texture condition nearby the surfaces affects the VDA bendability the most. However, the microvoid formations also contribute in faster cracking phenomena during the load drop of the VDA bending test.