Study On Preparation And Tribological Properties Of UHMWPE/Ni Composite Coating

Friction and wear is one of the main causes of surface failure of parts.Surface treatment of parts is an economic and effective way to improve their service life.There are many methods of surface treatment for parts,among which composite coating is widely used because of its simple preparation equipment and high economy.Ultra high molecular weight polyethylene(UHMWPE)has excellent antifriction and wear resistance.It is expected to further improve the tribological properties of the coating when it is added to the composite coating.However,UHMWPE has strong hydrophobicity,which can not be added to the coating by composite electrodeposition.Therefore,in this paper,the surface hydrophilic treatment of UHMWPE particles is attempted first,and then UHMWPE/Ni Composite coating is prepared by composite electrodeposition.At the same time,in order to improve the content of UHMWPE particles in the composite coating,electrophoresis + electrodeposition(twostep)method was used to prepare the composite coating.Then the surface quality,microhardness,bonding strength,residual stress and Tribological Properties of the composite coating prepared by the two processes were tested.Finally,the effect of heat treatment on the properties of UHMWPE/Ni Composite coating was also investigated.The main research work and conclusions are as follows:(1)UHMWPE particles treated by hydrophilic treatment can be added to the composite coating by composite electrodeposition,but the content of particles in the composite coating is relatively low at this time,and the method of electrophoresis + electrodeposition can effectively improve the content of particles in the composite coating;(2)UHMWPE plays an important role in improving the friction reduction and wear resistance of the composite coating,and with the increase of UHMWPE particle content,the friction reduction and wear resistance of the composite coating will increase,but the mechanical properties of the composite coating,such as hardness,bonding strength and residual internal stress,will decrease in part;(3)Heat treatment can significantly improve the wear resistance of UHMWPE/Ni composite coatings.However,as the heat treatment temperature increases,the surface hardness and coating bonding strength of the composite coating will decrease.