Comparison between microwave and conventional heating on microstructure and final properties of Al-SiC-TiC composites

Al-SiC-TiC composites were synthesized via two different procedures: conventional and microwave sintering. Green samples with initial composition of Al 80 wt%, SiC 15 wt% and TiC 5 wt%, were subjected to sinter at 650, 750, 850 and 950°C for 1 h and 1 min in a conventional and a microwave furnace, respectively. The results indicated that the optimum density is corresponded to the sintering at 750°C which is 93% and 97% of the theoretical density for conventional and microwave samples, respectively. Furthermore, maximum bending strength for the samples was equal to 305 and 340 Mpa. XRD analysis showed that the intensity of SiC and TiC peaks begins to diminish at higher sintering temperature (above 850°C). Eventually, SEM studies revealed a homogeneous distribution of carbide phases within the Al matrix.