| The inherent characteristics of aluminum alloys,such as low hardness,low strength,and poor wear resistance,limit their application as lightweight wear-resistant components in harsh working conditions.Therefore,it is necessary to modify the surface of aluminum alloy to improve its comprehensive surface performance,which is important to improve the service life of aluminum alloy and expand its application.410 stainless steel has been widely used in surface engineering due to its high toughness,good hardness and wear resistance,and low material cost.In this paper,410stainless steel coatings with different deposition states were prepared on the surface of6061 aluminum alloy using high-velocity oxygen-fuel（HVOF）technique.The microstructure of the coating was analyzed by XRD and SEM,and the mechanical properties and friction wear properties of the coating were tested by microhardness tester,scratch tester and ball and disc friction wear tester,and the wear mechanism was analyzed.The details are as follows:The study on the microstructure of 410 stainless steel coating with different oxygen-fuel ratios and its mechanical properties showed that:as the oxygen-fuel ratio increased from 4.36 to 5.51,the unmelted and semi-molten particles in the coating decreased,the structure became uniform and dense,the porosity of the coating decreased from 0.71%to 0.38%,the microhardness decreased from 592 HV0.1 to 586HV0.1,the surface roughness in the sprayed state decreased from 11.35μm to about7.05μm.The coating bonded well with the aluminum alloy substrate.The results of the coating scratch experiments show that the cohesive strength of the coating increases with the increase of the oxygen-fuel ratio,and the scratch resistance increases.The results of the dry sliding friction test between the coating and the substrate showed that the wear rate of the coating was reduced by nearly two orders of magnitude compared with the aluminum alloy substrate under the friction condition of 10 N and 562.8 r/min.The coating wear rate decreases from 17.96×10-6 mm3 N-1 m-1 to 9.35×10-6 mm3 N-1 m-1 as the oxygen-fuel ratio increases,and the main wear mechanism of the coating changed from delamination wear and abrasive wear to oxidation wear and slight abrasive wear during the stable wear stage.When the oxygen-fuel ratio is 5.51,the coating has lower porosity and homogeneous microstructure,and the coating has lower tendency of delamination wear.The frictional wear performance of the uniform and dense 410 stainless steel coating（OF-5.51）was tested at different rotational speeds（280 r/min-840 r/min）,different loads（10 N-20 N）,and different friction pairs（Si3N4 and GCr15）in a room temperature atmospheric environment to investigate the influence of friction parameters on the wear mechanism of the 410 stainless steel coating.The results showed that the load was constant at 10N,when the rotational speed increased from280 r/min to 840 r/min,the microcutting rate of the wear surface increased,oxidation increased,and the main wear mechanism changed from microcutting to abrasive wear and oxidation wear.Where the speed is 840 r/min,Fe3O4 plays a dominant role on the wear surface and generates self-lubrication,and the wear rate and friction coefficient of the coating is lower than that at 700 r/min.When the rotational speed is 560 r/min and the load is increased from 10 N to 20 N,the oxidation wear and abrasive wear of the coating increases,while the shear stress on the coating increases,which easily produces larger plastic deformation at the coating defects and induces the occurrence of delamination wear,and when the load is larger（≥15 N）,the tendency of coating delamination wear increases.The wear rate of the coating is 14.39×10-6 mm3 N-1 m-1when the opposing substrate is GCr15 steel ball,which is about 37%higher than the wear rate when Si3N4 is used as the opposing substrate,and the wear mechanism of the coating is adhesive wear,oxidation wear and slight abrasive wear at this time. |
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