Preparation Of Plasma Cladded CeO₂/Graphite/CoCrFe Coatings And Tribological Property Of Micro-textured Surface

Gray cast iron is widely used in the field of mechanical engineering due to its good process performance and low cost.Due to the relatively low hardness and strength of gray cast iron and poor corrosion resistance,defects such as cracking,corrosion,and abrasion often appear during long-term service,which leads to component failure.Every year in our country,a large number of gray iron castings are scrapped and cause major economic losses.Therefore,improving the wear resistance and corrosion resistance of gray cast iron has important engineering application significance and certain theoretical research value.In this paper,it is contemplated that the surface to reduce the wear resistance and corrosion resistance of the gray cast iron is the background,and the plasma/laser is prepared to prepare a CoCrFe compound coating on the HT250 gray cast iron,and the tissue morphology is observed,performance test,preferably Suitable preparation processes,by adding graphite lubrication phase to the mucous material to increase the resistance wear resistance of the coating,the results show that after the graphite is added,the hardness and ground resistance of the mucating layer are significantly prematurely after the addition of graphite.Increased,but there are more air pore defects,and the corrosion resistance of the molten layer is lowered.To this end,the rare earth oxide CeO₂ is further improved on the muccating layer.By observing the micro-morphology of the coating,the gas hole problem of the coating is significantly improved and the corrosion resistance is improved,and the quality of the quality excellent quality is finally prepared.On this basis,laser surface texture treatment is performed on the coating,and the effects of surface texture on coating triboal properties are explored.1.By comparing the formability,wear resistance and corrosion performance of plasma cladding and laser cladding,it is found that the overall performance of plasma cladding cobalt-based coating is the best;2.The addition of graphite generates a large amount of carbide hard phases in situ in the cladding layer.The cladding layer is mainly composed of?-Co and(Cr,Fe)₇C₃,and the hardness and wear-reducing and wear resistance properties have been significantly improved.Compared with the cladding layer with graphite added,when 7.5 wt.%graphite is added,the average microhardness is about 716.3 HV_0.3,which is an increase of 18%;the average friction coefficient is 0.37,and the friction reduction performance is increased by 30.4%.But the corrosion resistance is reduced,and pore defects appear;3.The addition of rare earth oxides improves the fluidity of the molten pool,purifies the grain boundaries,and solves the problem of pore defects in the cladding layer.With the increase of CeO₂ content,the structure of the cladding layer is gradually refined and the corrosion resistance is also obtained.Significant improvement;4.The surface texture has the functions of oil storage and collection of wear debris,which significantly improves the wear-reducing and wear-resistant performance of the coating.