Magnesium-alloy die forgings for automotive applications

Abstract

The paper presents an investigation of the effect of process variables and material condition on the forgeability of magnesium wrought alloys of the Mg-Al-Zn group. The experimental work included the studies of forging capabilities of the alloys in open-die forging at hot- and warm-working temperatures. Forging tests were performed for the material in both the as-cast and as-worked conditions, for two variants of the work-piece geometry. Different variants of the work piece indicated fracturerelated problems in forging magnesium alloys in the warm-working temperature mode, which involved an interaction between the material composition and process variables, and the state of stress. By means of numerical calculations it was concluded that, in addition to the material condition, the favourable state of stress, provided by a closed die, could greatly improve the formability of magnesium alloys in the warm-working range.