The study of effective process parameters in warm sheet hydroforming

Nowadays, in different industries, especially in the automotive industry, the use of lightweight materials such as aluminum alloys has been increased in order to reduce the weight of parts and fuel consumption. These alloys have low formability at room temperature. To overcome this problem, forming at elevated temperatures is proposed. In this paper, formability of 5052 aluminum alloy sheet under hydrodynamic deep drawing assisted by radial pressure process has been studied at warm condition. Initially, after analyzing the effect of geometric parameters on thickness distribution and punch force, the effect of temperature, fluid pressure and punch speed on thickness distribution, punch force and limiting drawing ratio (LDR) were investigated. Also, the effects of forming temperature and punch speed on the minimum thickness of the workpiece were studied using Taguchi method. Based on the obtained results, higher temperature in warm isothermal and non-isothermal states leads to decrease and increase in the part thickness, respectively while higher punch speed helps in thickness improvement. It was found that the LDR increases with increasing temperature in non-isothermal state and with decreasing temperature in isothermal condition. In addition, increase in fluid pressure leads to a higher LDR.