Similar to conventional deep drawing, blank holder force in sheet hydrostatic forming plays an important role in avoiding instability on flange and creating good condition for forming of material into die cavity. Moreover, blank holder force also has an important function to tight material on flange in contact with die to prevent leakage of working fluid to lose high pressure of fluid in the chamber. Therefore, it is necessary to investigate the impact of blank holder force on other factors such as working pressure of fluid to achieve the best product quality. The article below shows the results of comparison between hydrostatic forming with constant blank holder force and changed blank holder force depending on stroke by experiment. Based on obtained results, it is possible to evaluate the influence of blank holder force on forming steps and product quality.
Keyword
Hydrostatic forming, blank holder force, working pressure of liquid
