Effect of nanometer TiC coated diamond on the strength and thermal conductivity of diamond/Al composites

50 vol% TiC-coated diamond particles reinforced 6061Al (TiC@diamond/6061Al) composites were fabricated by using powder metallurgy method. The TiC coating 10 nm in thickness on the diamond particles could improve the wettability and increase the bonding between the diamond and Al matrix. The density of the TiC@diamond/6061Al composites reached 99.6% of the theoretical density, which was much higher than that (96.7%) of the composite using the diamond without the TiC layer (Diamond/6061Al). The bending strength of the TiC@diamond/6061Al was 396 MPa, 35% higher than that of the Diamond/6061Al. However, the thermal conductance of the TiC@diamond/6061Al was only 13.4% higher than that of the Diamond/6061Al. This indicates that the massive gap in phonon velocity between diamond and Al, not the pores in the composites, was the dominant factor in the thermal conductance of the diamond particles reinforced Al composites.