Enhanced mechanical and electromagnetic-wave-absorption properties of ceramic matrix composites fabricated by novel laser-machining-assisted CVI

A novel technique based on laser-machining-assisted chemical vapor infiltration (LA-CVI) was proposed and developed to fabricate ceramic matrix composites (CMCs). The results showed that the compressive strength, the shear strength and the bending strength of the C/SiC composites increased by 50.7 %, 11.8 % and 17.8 %, respectively, compared with those of classical CVI-C/SiC composites. The improvement can be attributed to the reopening of the diffusion channels and formation of a dense band and a coating around the channels. On the other hand, the minimum reflection loss (RL) of the C/SiC composites fabricated by means of LA-CVI improved 307 % against that of CVI-C/ SiC composites in the frequency range of 8 GHz to 18 GHz owing to the multiple reflection of the electromagnetic (EM) waves in periodic micro-holes. The advantages of the LA-CVI method with regard to improving mechanical properties and the EM-wave-absorption properties of CMCs were demonstrated.