Study On Wear Resistant Self - Lubricating Coating On Titanium Alloy Surface By Plasma Surfacing

The titanium alloy has high strength,good corrosion resistance,good oxidation resistance and high temperature performance.The titanium alloy is widely used in various fields.However the titanium alloy has disadvantages of high friction coefficient and poor wear performance.In recent years, more and more of the surfaces are strengthened by plasma welding technology.Its advantages include the following:low dilution rate, high rate of cladding,for a variety of metal powders.In this paper, plasma welding technology is used to prepare the self-lubricating wear-resistant coating in the titanium alloy surface.In the welding process,nickel-based alloys adding different lubricants in order to prepare composite coating depending on the ratio.Optimization of process parameters select the optimal welding parameters. Finally obtained the good self-lubricating wear-resistant coating.Analyze microstructure of Plasma Surfacing then summarize each microstructure morphology.Test microhardness of Plasma Surfacing and compare different process parameters of microhardness then summarize the wear mechanism coatings with friction mechanism.Test electrochemical corrosion of the coatings.Obtained NiCrBSi surfacing in TC4 by plasma welding technology.changing the welding current size and respectively getting different welding coatings, then analyzing the difference of macroscopic morphologies、dilution rate、microstructure、 crack rate、micro-hardness, finally summarizing the influence of welding current on surfacing coating.AddingNi60/5%WS2, Ni60/10%WS2, Ni60/5%MoS2, Ni60/10%MoS2 into surfacing alloy powder respectively.Exploring the effect of surfacing layer of macroscopic morphology and microstructure in different process parameters and different amounts of lubricant. Testing hardness and friction and wear properties of the coating and testing each coating electrochemical corrosion.After adding lubricants different ingredients,different lubrication phases appear in the coating.After adding a certain amount of WS2,wear rate increases compared with the Ni60 coating and with the increase of the added amount coating wear rate increases.After adding MoS2,friction coefficient of coating reduced significantly.And with the increase of the added amount, the coefficient of friction surfacing layer decreased.Compared with the Ni60 coating,the corrosion resistance of the coating did not change significantly.After adding WS2,corrosion tendency of the coating becomes large and Thermodynamic stability is weakened.