Numerical investigations of cutting temperature and cutting forces in cryogenic assisted turning of magnesium alloy

Abstract

Magnesium alloys are biocompatible materials that are not only used in biomedical implants but also in many engineering load-bearing applications due to their high strength to density ratio. However, machining of these alloys is somehow challenging, for example, magnesium alloy (AZ31B) is prone to ignition risk at relatively low temperatures during various machining processes. This ignition risk can be avoided by performing machining under cryogenic conditions. In the present research work, 2D finite element-based analysis of orthogonal cutting process of magnesium alloy (AZ31B) is performed considering both cryogenic and dry machining environments. Finite element simulations are performed by varying the cutting speed and uncut chip thickness. A widely employed, damage-based Johnson-Cook flow stress model is exploited to perform coupled thermo-mechanical cutting simulations. Cutting forces and temperatures are the major output parameters of interest in the work. The resultant cutting forces predicted by FE analysis for cutting speed of 100 m/min and for uncut chip thickness of 0.1 mm vary by 19% and 16% for cryogenic and dry machining conditions, respectively, when compared with available experimental results from literature, whereas, in the workpiece body, temperature variations of 14% and 2% have been found for cryogenic and dry machining conditions, respectively. Promising results of numerical model may help to further investigate and optimize the process.