Feasibility of micro-hole machining in fiber laser trepan drilling of 2.5D Cf/SiC composite: Experimental investigation and optimization

The special structure characteristics make 2.5D C-f/SiC composite a key material in high-temperature parts of aerospace field. However, the micro-hole machining based on fiber laser has been a challenge due to effect of taper and heat affected zone. This paper proposed the feasibility on high-quality micro-hole machining of the 2.5D C-f/SiC composite by using fiber laser trepan drilling, including experimental investigation and optimization analysis for the first time. The key laser parameters, such as scanning speed, pulse frequency, pulse width, defocus amount, and energy percentage are introduced as the optimization parameters, and taper and average thickness of heat affected zone (HAZ(a)) are chosen as objectives. A comprehensive analysis method including Taguchi L-16(4(5)) orthogonal array, analysis of variance (ANOVA), regression modeling, and multi-objective genetic algorithm (MOGA-II) is presented on fiber laser trepan drilling to minimize the taper and the HAZ(a). The importance and interaction of the laser parameters on the taper and HAZ(a) are obtained. The results show that the fiber laser trepan drilling integrated with the proposed experimental and optimization analysis can achieve the high-quality micro-hole machining of 2.5D C-f/SiC composite. The presented methodology can be also used in high-quality machining of other fields.

Automated summary

By using fiber laser trepan drilling, high-quality micro-hole machining of 2.5D C-f/SiC composite can be achieved. Optimization methods including Taguchi orthogonal array, analysis of variance, regression modeling, and multi-objective genetic algorithm can minimize taper and heat affected zone.