Optimization of process parameters for electromagnetic induction heating assisted extrusion of magnesium alloy AZ91D internal thread

Abstract

The forming of magnesium alloy AZ91D internal thread by electromagnetic induction heating assisted extrusion is a new processing method. In this work, on the basis of this process, the torque in the forming process is selected as the evaluation index, and the response surface method is used to analyze the influence of the process parameters on the internal thread forming process. The range of process parameters (auxiliary heating temperature, hole diameter, machine tool speed) is determined by slip line and empirical method, the test data are simulated, modeled and compared with the response surface analysis method, and the best mathematical model is selected to establish the regression model. the three-dimensional response surface curve of torque is obtained. Through simulation and prediction, it is found that the hole diameter and auxiliary heating temperature have significant influence on the torque in the forming process, and the order is that the hole diameter is larger than the auxiliary heating temperature than the machine tool speed. At the same time, it is found that the interaction between the auxiliary heating temperature and the machine tool speed has a significant effect on the torque. The research results show that the measured value of torque is close to the predicted value, and the predicted value is 3.1% lower than the actual value, and the model fits well. The better forming process parameters are as follows: auxiliary heating temperature to be 240°C, hole diameter to be 11.45 mm, machine tool speed to be 100 r/min. under this parameter, the torque in the forming process to be 24.751 N·m.