Machining feasibility comparison of homogeneous SiC and SiCf/SiC, Cf/SiC and CFRP composites processed by a green-light femtosecond laser

Abstract

Purpose Continuous fiber-reinforced polymer or ceramic matrix composites are advanced materials and have been widely used and developed rapidly in the aerospace and automotive industries. However, their excellent mechanical performance causes severe tool wear and poor machining quality, bringing great challenges to machining. The purpose of this article is to reveal the processing characteristics and commonalities of fiber composite materials processed by ultrafast laser through material comparison research. Design/methodology/approach Femtosecond laser is a special precision machining technique with significant demand in the aerospace field. This paper carried out a green-light femtosecond laser grooving for four different composites. In particular, the machining feasibility and behavior for homogeneous SiC, SiCf/SiC, Cf/SiC and Carbon Fiber Reinforced Polymer/Plastic (CFRP) composites were studied and compared, including grooving depth, ablation rate, taper angle and ablation threshold. Materials’ thermal properties like evaporation enthalpy and thermal conductivity combined with their structural interfacial thermal resistance were found to be the main factors determining their processing performance. Findings Results showed that, by the machining ability and efficiency increasing order or decreasing order of ablation thresholds, they were ranked as follows: SiC, SiCf/SiC, Cf/SiC and CFRP. Proportionally increasing pulse frequency and grooving speed, slight variations of the groove width, grooving depth, ablation rate, heat-affected zone and groove taper angle were obtained. Originality/value Thus, the analyzed machining method provided high-speed grooving that improved processing efficiency without deteriorating processing quality.