微尺度激光喷丸强化TiN涂层的实验研究

Microscale laser shock peening (μLSP) based on laser shock peening (LSP) is a novel surface modification technology aimed at metal microstructures, with micrometers laser spot and μJ~mJ laser energy. μLSP on TiN coating is investigated in this study to further improve the surface properties of TiN coating. Optical profile and nano mechanical test system were used to observe and measure the surface morphology, nano-hardness and elastic modulus of TiN coating in peening area. The experimental results show that a conical dent was formed in peening area after μLSP, the biggest depth is about 1.2μm; the nano-hardness and elastic modulus were significantly changed in the center of peening area, and within a certain range, they are enhanced with the increase of laser energy. When the laser energy is 250mJ, the nano-hardness and elastic modulus are both reached the maximum, 50.21GPa and 402.8GPa respectively. Compared with the initial state of TiN coating before μLSP, they are increased by 140% and 43.9% respectively.