Study On The Process And Properties Of Self-Lubricant Ni-P-Graphite Electroless Composite Coating

In the fields of avigation or special industry, work condition of materials have greatly different from common. At condition of high or low temperature, vacuum,airpoof etc, traditional lubricant no wrok, so there were important meaning to explore materials with lubricate function.To deal with the problems of the bath solution decomposing easy during tests and the graphite reuniting in coating , the effects of many parameters such as main salts ,reducers, complex agents, surfactants, quantity of graphite added into bath solution, bath temperature and PH ect.on the solution stability, the depositing velocity and the performance of coating were studied entirely by some parallel tests and two orthogonal tests in this paper.In addition ,it was investigated outstanding that the surface properties of graphite were changed by surfactants in several methods about graphite scattered into bath solution.Finally, appropriate techniques parameters were made sure.The composite coating of graphite scattering equality, better wearable, antifrication and an-corrodent was made by process said before. The micromorphology, microstructure, microhardness, friction coefficient, abrasion amount, wear resistance capability, etc. of coatings were analysed by XRD, SEM and other instruments. The results of the test showed that the structure of Ni-P-Graphite coating is Graphite grains inlayed in Ni-P,its microhardness and an-corrodent exist no distinct difference from Ni-P,but its friction coefficient, abrasion amount under dynamic were much lower than Ni-P coating—better wearable and antifrication performance .In addition, the influence of heat treatment on the microstructure and properties of coatings were also studied. The results showed the strcture of Ni-P and Ni-P-Graphite coating changed gradually from no crystallization to crystallization,and the change was over at 400℃.Its microhardness and wearable and antifrication abilities were more improved after heat treatment,neverless an-corrodent ability declined after itIn addition, the paper made a preliminary discussion on the mechanism of electroless composite codeposition and stability of bath; and analysed the dispersing mechanism of the particles in the bath. Meanwhile the common law of the deposition rate was studied on the dynamic aspects.