Research On Preparation And Antifriction Properties Of Lubricating Composite Coating Containing Graphene

In this paper,we discussed the preparation of graphene by REDOX method and the modified graphene oxide by KH550.Then researching the tribological properties of graphene/Ni composite coatings,modified graphene oxide/Ni composite coatings,graphene/MoS2/Ni composite coatings.SEM,XRD,Raman,FI-IR,TGA and XPS were used to analyze morphology and composition of graphene and modified graphene oxide.Then we compared the influence of different reducing agents on the quality of graphene.Using double pulse electrodeposition process to prepare the nickel based composite coatings with different kinds and amount of additive under different current density and different plating time on 45#steel surface.It's tribological properties were tested by using friction-wear machine with Si3N4 ball.Micro hardness tester and confocal 3D profiler were used to evaluate the mechanical properties of composite coating.SEM,EDS,XRD,Raman were used to analyze phase and composition.The results show that the reduced graphene oxide using trisodium citrate has higher order degree and higher thermostability and it's C/O atomic ration increases by 73.60%compared with hydrazine hydrate.Cathode current density has great impact on wear rate of composite coatings.The wear rate decreases by 83.15%when the cathode current density changes from 0.67A/dm2 to 2.00A/dm2.We find roughness and friction coefficient of composition coating decrease with anode current density improved.The hardness and deposition rate increase,meanwhile,friction coefficient and wear rate decrease with the content of graphene or modified graphene oxide increased.What's more,modified graphene oxide/Ni composite coating has better properties than graphene/Ni composite coating with the same addition amount.When the addition amount is 0.04g/L,for modified graphene oxide/Ni composite coating,the grain size decreases by 13.17%,deposition rate increases by 188.00%,hardness increases by 24.36%,and wear rate decreases by 45.10%compared with graphene/Ni composite coating.Different addition amount of graphene and 0.1 g/L MoS2 were added into plating solution.With the addition amount of graphene increased,the grain size of composite coating increases initially then reduces and the minimum grain size of Ni(200)is 17.85nm when the content of graphene and MoS2 are 0.04g/L and O.10g/L separately.The graphene/MoS2/Ni composite coating has better properties than graphene/Ni composite coating.When the addition amount of graphene is 0.04g/L,for graphene/MoS2/Ni composite coating,the hardness increases by 60.24%,friction coefficient decreases by 47.11%and wear rate decreases by 87.69%compared with graphene/Ni composite coating.