The formation of Ni-Ti intermetallic coatings reinforced by TiC particles on AISI 304 stainless steel surface using Ni-Ti-C elemental powder mixtures via GTAW process has been studied in this research. The elemental powder mixtures with calculated stochiometric proportions were milled as first step. Then those mixtures were pressed to form a bricket called filler alloy and subsequently melted on steel substrate using GTAW process. The microstructure and phase structure of specimens were studied using optical microscope and SEM and XRD respectively. The micro hardness of specimens were measured using Vickers indentor and wear tests were done using pin on disc method. The results show that milling and subsequent GTAW melting of Ni-Ti powder mixtures lead to formation of dual phase NiTi/Ni 3 Ti structure which have thickness of 1.5 mm with hardness degree of at least 600 Hv while same process using Ni-Ti-C powder mixture lead to formation of dual phase NiTi/Ni 3 Ti structure containing TiC particles which have excessive thickness of 100 to 300 HV depending on the reinforcing phase content. The formation of these phases were analyze dusing process kinetics and equilibrium phase diagram of Ni-Ti and were compared by the microstructures of coatings. The analyses results reveal that the formation of TiC in these coatings is prior to the formationof Ni-Ti intermetallics. TiC also has an important effect on the location and constitution of intermetallic phases by depleting Ti atoms of adjacent regions. Evaluating wear behavior of coatings reveals that the addition of TiC in matrix has a coicuous effect on decreasing the mass loss during wear tests. It seems that abrasive wear is the dominant mechanism in wear of unreinforced coatings and its role decreases with addition of TiC to the matrix.
