The effect of thermo-mechanical processing on the structure, static mechanical properties and fatigue behaviour of pure Mg

Abstract

Magnesium alloys find important applications in automotive, aircraft and space industries. Magnesium itself is also a key component in biodegradable metallic materials considered for applications in medicine. Although there are many studies that include the mechanical behaviour of pure Mg and its alloys after different thermomechanical processing, there is a huge impact of the processing method on the observed properties. Based on these facts, predicting the final properties is difficult. This paper deals with the preparation of pure Mg using a classic extrusion method with a low extrusion ratio, slow extrusion rate and low temperature. These parameters were selected to prevent an excessive grain size and to obtain optimal mechanical properties. The prepared materials were subsequently heat treated under different conditions and the relations between the grain size, texture strength and mechanical properties were studied. As well as static mechanical tests in tension and compression, fatigue tests were also performed. Finally, the obtained data were fitted using the Hall-Petch relation and the results were compared with the literature. The observed results confirmed the significant effect of processing on the mechanical properties with a strong impact on the Hall-Petch behaviour.