Interfacial Wettability and Thermal Conductivity of Diamond/Al Based Composites with Ti and B Additions

Al-based and Al-alloy-based diamond composites were made by pressure infiltration process in order to obtain composites with high thermal conductivity and light weight for thermal management applications. Interfacial bonding strength and thermal physical properties of the Al-alloy-based composites were improved with additions elements of Ti and B. Influence of Ti and B on interfaces at 950 °C between diamond and Al matrix were found to play an effective bridge role of wettability, a large improvement of selectivity was observed between {100} and {111} diamond surfaces. SEM and EDS analysis suggested that the segregation of B element was confirmed to have primary effect on the interfacial bonding. The as-fabricated diamond/Al (Ti, B) composite exhibited thermal conductivity value as high as 449 W/m·K, thermal expansion coefficient as low as 6.2 × 10-6 K-1, and the bending strength as high as 312 MPa.