Effect of Laser Shock Peening of WAAM Deposited Ni–Ti Shape Memory Alloy on the Mechanical Property

Abstract

Wire Arc Additive Manufacturing (WAAM) is an emerging field of manufacturing due to its degree of freedom for large-size components with complex geometry and high deposition rate. However, owing to higher heating and sudden cooling cycles during the deposition, tensile residual stress is generated in the fabricated sample. In this work, WAAM and Laser Shock Peening (LSP) are deployed to improve the mechanical and functional properties of Ni–Ti shape memory alloy. Ni–Ti wall structure was fabricated in five layers with a voltage of 16.5 V and wire feed rate of 5.5 m/min for 10 s delay after each layer. Laser shock peening was performed with the laser power of 1 W. The as-deposited WAAM and LSP samples were appraised its mechanical and functional properties using an optical microscope, microhardness, and Differential scanning calorimetry (DSC). The optical microscope images of LSP samples revealed the grain refinement compare to the as-deposited sample. During the LSP process, the generated laser-plasma induces the compressive residual stress that enhances the microhardness values of the laser peened examples. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.