Study on the Incremental sheet metal forming process using a metal foam as a die

The incremental sheet metal forming (ISF) process has the flexibility to manufacture components without a specific die-set. In detail, a small incremental deformation by the forming tool movement is accumulated to form a target geometry. However, the formed part's geometrical accuracy is often observed to be lower due to no external die support. This research work is aimed to replace the commonly used dies with a nickel-metal foam that acts as flexible die support in the ISF process for improving the geometrical accuracy. The pure nickel metal foam was employed with various densities such as 20, 50, and 80 pores per inch (PPI) to identify the proper flexible support configuration. The current research work is summarized in three fields: (i) at first, the indentation tests were conducted to investigate the material deformation characteristics of the nickel-metal foam. The numerical results revealed that the high-density nickel-metal foam showed good geometric accuracy compared to other configurations. (ii) according to the indentation results, the ISF experiments were carried out with a nickel-metal foam, and the shape error was estimated for the formed parts. The findings showed that the shape accuracy was improved with the use of flexible die support compared to the conventional ISF process, and (iii) to save material costs, the nickel-metal foam was reused for manufacturing new parts and confirmed the reusability. Thus, the results show that employing proper density compressed nickel-metal foam influences geometric accuracy positively and can be devised for manufacturing complex geometries in the ISF process.