Nickel plays an important role to the thermodynamics and reaction dynamics in self-propagation high temperature synthesis
reactions,but little is currently available on the action of nickel in
high velocity oxy fuel flame spraying (HVOF).Thus the influence of Ni on the microstructure and wear resistance of HVOF TiC-Ni cermet coatings with varies Ni content was investigated.Results showed that Ni was able to absorb reaction heat,retard the oxidation of the granulated ingredients,and increase the interfacial bonding strength of the target cermet coatings.Moreover,the microstructures and wear resistance of the target cermet coatings were highly dependent on the Ni content in the granulated raw materials.Namely,the cermet coating prepared from the granulated raw materials of a low Ni content was composed of a large amount of oxides and had incompact microstructure and poor wear resistance.Contrary to the above,the cermet coating prepared from the granulated raw material of an increased Ni content as much as 40% contained less amount of oxides and increased wear resistance.However,the cermet coating prepared from the granulated raw material of an extremely high content of Ni had a high content of flake-like Ni and increased space among the hard phases,which corresponded to a decreased wear resistance as well.