Closed die forging of a Mg–Al–Ca–Mn–Zn lean alloy

Abstract

The intensifying search for light weighting possibilities in transportation have repeatedly brought attention on wrought Mg alloys. While various alloys have been investigated a trend in development towards heat treatable Mg alloys with low alloying content has been noticeable. Investigations on wrought alloys are done predominantly by extrusion or rolling, but not by forging. As forgings are an indispensable part in structural components used today, it is important to gain an in depth understanding of the interaction between material, forming process and heat treatments of forged parts.In this study, the forging process of a piston rod using an age-hardenable lean Mg alloy AXMZ1000 is investigated on a semi-industrial scale, comparing two different stock materials: cast and homogenized versus extruded forging material. The microstructural evolution and mechanical properties during the production process are analyzed and assessed. Comparable microstructures are obtained with both starting materials. The mechanical properties achieved are slightly better with extruded feedstock than with the cast counterpart, but are at a satisfactory level comparable to extruded or rolled components made of similar alloys.