Laser cutting process is widely used across the engineering sector for processing metals and alloys. Over the last few years there has been an increasing interest in exploiting ceramic matrix composite (CMC) based materials for both high and low-temperature applications in aerospace, power generation and nuclear applications, due to their superior thermal and structural properties. However, laser processing of anisotropic composites such as CMC is difficult due to its high melting temperature, and the differences in the physical and thermal properties of the resin/matrix and fibre. This research discusses about laser cutting of silica based CMC material using a continuous wave fibre laser operating at an average power of 2kW.
The influence of various laser, kinematic and assist gas parameters on cut quality and speed was investigated, and the effect of various cutting strategies was studied in detail. The laser cut samples were analysed for surface and sub-surface cut characteristics using optical microscope, surface profiler, scanning electron microscope and X-Ray CT scan. Irrespective of the conventional wisdom (that high-power long pulse lasers are not suitable for composites) CW laser can be used to cut a 5 mm thick CMC material in line with the speed and quality requirements of the manufacturing industries. Multi-pass laser cutting shows better cutting performance, in terms of both speed and quality than the conventional single pass cutting technique. Assist gas composition plays a major role in controlling the material removal mechanism, and significantly influences the cut quality.