Experimental investigation of thin sheet formability during laser shock forming

• Main Author: Dong, Anna Siling
• Other Authors: Sylvie Castagne
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/53601
• Institution: Nanyang Technological University

The increasing demand in the fabrication of micro systems has highlighted the significance of micro forming processes. However, existing micro forming techniques has limitations whereby a new metal forming process for sheet metals is developed and introduced in this project. The new forming process, Flexible Pad Laser Shock Forming (FPLSF), will be an advantage to the future development of micro forming. It uses shock wave induced by laser irradiation to shape sheet materials without the usage of complex micro molds. The combination of Laser Shock Forming and a flexible pad has significant advantages such as high flexibility from the process, short process cycle time and high strain rates. This project achieves to study the formability of stainless steel sheet metal during FPLSF. Influence of effects on laser processing parameters are studied and discussed. Process outcomes such as deformation profile, hardness and thinning of the metallic foil are analyzed through experimental investigations. Deformation depth is examined to be proportional to the laser fluence while the shockwave amplitude affects the deformation diameter. Hardness value of stainless steel thin foils varies along with the increase in laser fluence. The increase in uniformity of thickness distribution in FPLSF is a significant advantage over processes that involves the usage of molds and maximum thinning is found to be at crater center. Comparisons between copper and stainless steel thin foils are analyzed to gain better understanding on the formability of metals during FPLSF.