An Investigation on Geometrical Accuracy in HSTR Metal Shapes Produced by Incremental Sheet Metal Forming

Incremental Sheet Metal Forming (ISMF) provides a versatile approach to producing complex shapes without expensive tooling, making it particularly valuable for aerospace, automotive, and biomedical industries requiring intricate and unique designs. Forming intricate shapes from these materials at room temperature presents significant challenges due to their inherent properties, higher yield strength, and limited ductility. ISMF was experimentally applied to high-strength thermal resistant (HSTR) sheet metals to assess dimensional accuracy in forming complex shapes. Using Stainless Steel (SS304), Nickel (Ni200), and Titanium (Ti Grade 2) sheets fabricated and measured with a Coordinate Measuring Machine (CMM). Symmetric square pyramid geometry was successfully formed at room temperature, with dimensional deviations precisely examined through randomly selected measurement points on the formed part. The analysis reveals significant variations in dimensional accuracy across different part regions, with minimum deviations of 0.0001 mm, 0.0018 mm, and 0.0581 mm observed in the x, y, and z axes, respectively, at specific measurement locations. Wall angle deviations ranged from a minimum of 45.0202° to a maximum deviation of 45.5780° from the target angle of 45°, demonstrating both the process capability and limitations when forming HSTR materials. The outcomes provide valuable insights into the challenges and potential of utilizing HSTR sheet metals in ISMF for manufacturing lightweight, high-performance components, establishing quantitative baseline data for process optimization and quality control strategies in customized and small batch production scenarios.