Formability studies of friction stir processed Mg AZ31 alloy in plane-strain stretch forming

Abstract

Magnesium alloys exhibit poor formability at room temperature because of their hexagonal close packed (hcp) structure. The grain refinement can improve its ductility and formability. Friction stir processing (FSP) is an emerging solid state surface modification technique that can produce homogeneous microstructure with fine-grains in a single pass. The effect of friction stir processing variables that can affect tensile strength and formability of magnesium AZ 31B alloy are studied. The formability of friction stir processed sheet was studied by limiting dome height (LDH) test in plane- strain deformation condition. The results indicate that the tensile properties and formability are improved by friction stir processing. The objective of the present work is to establish randomisation of texture to increase work hardening exponent by favourably orienting a large number of grains (texture) in AZ31 alloy to improve its stretch formability by promoting additional straining in thickness direction