Experimental And Numerical Investigation Of Large Strain Extrusion Machining Of AZ31 Magnesium Alloy For Biomedical Applications

Magnesium alloys represent promising bioresorbable orthopedic materials thanks to their biocompatibility, non-toxicity, and mechanical properties that are pretty close to the ones of the human bone. Nevertheless, the major drawback that impairs their widespread adoption in the biomedical field is represented by their unsatisfactory corrosion resistance once placed in the human body environment. Several research studies have demonstrated that an effective method to control the degradation rate of magnesium alloys is represented by a proper conditioning of the surface characteristics of the alloy. With this in mind, the present work proves the feasibility of using Large-Strain Extrusion Machining (LSEM), namely a hybrid cutting-extrusion process, as a strategy to sensibly affect the surface features of the AZ31 magnesium alloy, and, as a consequence, its corrosion performances. The microstructure and micro-hardness close to the machined surface was investigated after LSEM. The experimental results were exploited to develop, calibrate and validate numerical simulations able to describe the microstructural and mechanical phenomena that occur under LSEM. The proposed approach shows that the simulation model can represent a useful tool to predict the magnesium alloy machining performances, thus reducing the need for numerous and time-consuming experimental tests to a great extent.