Thermo-Mechanical Investigation on Hot Deformation Behavior of Cast Magnesium–Aluminum Alloy: Experimental and Constitutive Analysis
摘要
The automobile, aerospace, military, computer hardware, and portable electronics industries are increasingly utilizing magnesium (Mg) for structural applications. However, these alloys exhibit low formability at room temperature due to a limited number of slip systems, which restricts their use in engineering components. This limitation can be addressed by activating additional slip systems at elevated temperatures. Materials can undergo various high-temperature bulk deformation processes, such as hot rolling, forging, and extrusion. Understanding the characteristics of hot deformation is crucial for optimizing processing parameters and controlling microstructural evolution. Current research focuses on the high-temperature deformation behaviour of AM50 Mg alloy within a temperature range of 250–450 °C, with strain rates varying from 10−3 to 1 s−1. Experimental results have been correlated with a developed constitutive model that accurately predicts the high-temperature deformation behaviour of the AM50 alloy. A dynamic materials model has been utilized to generate the processing map for the alloy, based on flow stress data obtained at different strain levels. Moreover, stress-strain curves and the processing map have been analysed to identify stability and instability regions. The optimal conditions for hot working the AM50 Mg alloy are found to be within a temperature range of 350–450 °C and a strain rate range of 0.005–0.1 s−1.