The role of Ti coating in enhancing tensile strength of Al/diamond composites

Aluminum matrix composites reinforced with Ti-coated diamond particles (Al/Ti-diamond composites) were produced by squeeze casting. The plating time of molten-salt was varied to investigate the effects on the phase structure and thickness of Ti coating on diamond particles. The highest tensile strength of 76 MPa was obtained for the composite with 90 min plating time. In this composite, a reasonable thickness of TiC layer was found to tightly connect Al matrix with diamond reinforcements. The tensile strength decreased when the plating time is longer than 90 min, owing to weak interfacial bonding between additionally formed Ti layer and Al matrix. The results show that appropriate selection of Ti coating can effectively improve interfacial bonding and tensile strength of Al/diamond composites.