A study on single-crystal alloy surface’s structure and performance of laser shock peening without absorbent coating

in order to determine how the laser shock peening without absorbent coating (LSPwC) affects Ni-base single-crystal superalloy, DD11, the surface structure and hardness gradient of single-crystal alloy after LSPwC of two pulse energies. The result shows that the width of linear structure is in direct proportion to the laser impact energy by observing the “linear” deformed structure through the scanning electron microscope, and the linear structure’s length increases when the pulse energy increases from 3J to 5J; the observation by the transmission electron microscope at ×10 000 show s that the linear structure is actually the “line cluster” formed by more than one parallel “fine lines”, and the fine lines are along the the [111] direction; the observation under a high resolution shows that fine lines are the single-crystal structure, the twinning plane is (1–11), and the twinning direction is [1–1–2].