Effect of laser shock peening on the tensile behavior and notch sensitivity of Ni-based single-crystal superalloy

In this work, a tensile specimen of a Ni-based single-crystal (SC) superalloy with a U-type notch was treated by laser shock peening (LSP). Nanohardness, residual stress, microstructure, and tensile properties were determined to analyze the tensile behavior and notch sensitivity of this alloy. The results showed that LSP induced multiple slip bands along the < 101 > orientations and facilitated the transformation of crystallographic structure at the cross-section from < 001 > to < 101 > orientations. The strain hardening capacity of the Ni-based SC superalloy was increased by LSP but was not sensitive to the strain rate. LSP effectively reduced the notch sensitivity of the Ni-based SC superalloy by introducing a beneficial compressive residual stress layer and a hardening layer and promoted the activation of the slip systems ( 1 1 1)[011],(1 1 1)[0 1 1], and (111)[10 1(- ) ] during the tensile tests at two strain rates.