The thermal fatigue resistance of cast iron with biomimetic non-smooth surface processed by laser with different parameters

Thermal fatigue cracks occur frequently on the brake drums’ surface, and this phenomenon leads to their premature failure. In order to improve their thermal fatigue resistance, according to the principles of biomimetic non-smooth surface, through processing striate units on the surface of cast iron samples by laser with different parameters, the thermal fatigue performances of smooth and non-smooth samples were investigated, respectively. The rules which laser parameters effected thermal fatigue resistance of non-smooth samples were analyzed. The results indicated that non-smooth surface could decrease thermal crack quantity and their propagation rates; thermal fatigue resistance was improved by processing non-smooth units on sample's surface. Different sizes of non-smooth units were obtained by adjusting laser parameters. The bigger non-smooth units resulted in better thermal fatigue resistance. Furthermore, the mechanisms of enhanced thermal fatigue resistance were studied.