Effect of Nano-TiC Particles on Microstructure and Properties of Ni-TiC Composite Coatings

Ni based composite coatings containing micro-and nano-TiC particles were prepared by dipulse electrodepositing in Watt's nickel solution.The effect of nano-TiC content in the solution on the micro morphology,microstructure,hardness and wear resistance of composite coatings was investigated.The results show that the agglomeration of composite coatings of Ni-TiC appears and the density decreases by adding nano-TiC particles in electrolyte,the microstructure of coatings consists of Ni and TiC phase; the hardness of composite coatings firstly increases and then decreases with increasing the content of nano-TiC in bath; however,the friction coefficient of coatings firstly decreases and then increases,the maximum value of microhardness of coating with 445HV is achieved when containing 6.0g/L nano-TiC in bath,at the same time,the smaller friction coefficient of coating is about 0.22.The wear mechanism is mainly abrasive wear.Coatings under the oxidation condition at 900[degrees]C for 100h show the best oxidation res