Effect of thermo-vibration assisted multi-pass with variable parameters on incremental forming quality of magnesium alloy

Abstract

Magnesium alloys are known for their poor plasticity at room temperature, making them difficult to form. Typically, heating is required to enhance their formability. However, even heat-assisted forming has limitations when it comes to improving the quality of the formed components. To further enhance the forming quality of magnesium alloys, this study explores the use of vibration in conjunction with heating, specifically through a multi-pass incremental forming process for magnesium alloys under combined thermo-vibratory effects. The research integrates thermal-vibration parameters with forming process parameters for comprehensive analysis. Initially, orthogonal experiments were conducted to examine the influence of different thermal-vibration parameters, such as temperature, vibration frequency, and amplitude, on the wall thickness and geometric accuracy of the workpiece. This analysis led to the determination of an optimal combination of thermal-vibration parameters. Subsequently, under these optimal thermal-vibration conditions, the effects of single-process parameter variations, including inter-pass angle, tool diameter, and layer spacing were examined, and their interactions on forming quality. Experimental validation confirmed the accuracy of the simulation model used in this research. The results revealed that the optimal thermal-vibration parameter combination consists of a forming temperature of 250 °C, a vibration frequency of 30 kHz, and an amplitude of 0.01 mm. Under these conditions, the minimum wall thickness of the workpiece improved by 3.24%. Furthermore, among the process parameters, the inter-pass angle had the most significant impact on forming quality, followed by the tool diameter, while layer spacing showed the least influence.