Effect of surface modification technology on the microstructure and properties of nickel based single crystal high temperature alloys

Nickel based single crystal high-temperature alloys are widely used in high-temperature working environments such as aviation engines, and their performance directly affects the reliability and lifespan of the engine. Laser shock, as a surface modification technique, can effectively improve the properties of metals. To investigate the effects of laser shock technology on the phase structure, microhardness, residual stress, friction and wear properties, and oxidation resistance of nickel based single crystal high-temperature alloys, experiments were conducted using equipment such as X-ray diffractometer, hardness tester, X-ray stress analyzer, and material surface performance comprehensive tester. The experimental results showed that after being subjected to laser shock, the volume fraction of the γ′ phase in the alloy was 72.6%, which increased by 15.2% compared to before laser shock. The phase composition of the alloy after laser shock did not change, the diffraction peak intensity gradually decreased, the microhardness showed an increasing trend, the residual stress on the alloy surface significantly increased, the friction coefficient gradually decreased with the increase of laser energy shock, and the oxidation resistance of the alloy was significantly improved. The experimental results indicate that laser shock technology can be used to improve the properties of nickel based single crystal high-temperature alloys, significantly enhancing their mechanical properties and fatigue life.