Microwave-Assisted Two-Step Sintering of Al/8wt%TiC Composite Prepared by Powder Metallurgy

In this work, two-step sintering (TSS) of Al/8wt%TiC with microwave heating has been performed successfully. The composites were fabricated by uniaxial pressing of mixed Al and TiC powders and subsequent sintering in an argon atmosphere at different sintering schedules. The observational studies show a well-dispersed TiC reinforcement in the Al matrix. According to the results, relative density and strength increased from about 95.5% and 90 MPa to 97% and 100 MPa for sintered composites at 640 °C for 2 h and 600 °C for 10 h with single step sintering by a conventional method, respectively. Also, applying the TSS method enhanced the values from 97% and 101 MPa for conventional TSS (T1=640, T2=600 °C) to 98% and 211 MPa for microwave-assisted TSS technique. It can be related to the more effective activation of the surface mechanism during fast microwave heating than the tube furnace dilatory heating. Consequently, decreasing the sintering temperature (T2) can proceed with densifying mechanisms.