Ni-TiC coating deposited on Ti-6Al-4V substrate by thermal spraying and laser remelting of Ni-clad graphite powder

A process of thermal spraying and laser remelting of a Ni-clad graphite powder to form a coating on Ti-6Al-4V substrate was carried out. A good coating without cracks and pores was obtained. The microstructure of the coating was examined using SEM and EDS. The coating mainly consists of austenitic nickel as matrix and TiC dendrite as reinforcement. During the laser remelting process, a reaction between C and Ti occurred, which lead to an in-situ synthesis of TiC reinforcement in the coating. The microhardness of the coating was measured using a Vickers hardness tester. The average microhardness of the composite coating is HV 1000 and it is two times greater than that of the Ti-6Al-4V substrate. (c) 2006 Elsevier B.V. All rights reserved.