Microstructure And Wear Resistance Of Nickel-base Self-fluxing Alloy Coating

In order to obtain good wear and corrosion resistant coating,the atmospheric plasma spraying equipment has used to spray nickel-base self-fluxing alloy powder on the surface of 45#steel and remelt the coating.after spraying,the coating has high porosity,and more microcracks at the interface between the coating and the substrate,which reduces the wear resistance and adhesion of coating.In order to improve coating properties,the saturated aqueous solution of boric acid has brushed on the surface of spraying coating,high temperature box type resistance furnace remelting and high frequency induction heating remelting are used into the sample which has brushed the saturated aqueous solution of boric acid and some without to remelt,and then the optical microscope has used to observe the two kinds of coating organization changes,test both before and after remelting the coating hardness and composition change and wear resistance.And then add 10%and 20%of Cr3C2-NiCr powder into the nickel-base self-fluxing powder,After fully mixing,spraying them on the surface of 45#steel,and heating the coating by the high frequency induction remelting method,then observing two kinds of coating organization change by the optical microscope and test their hardness and wear resistance after remelting,compared with Cr3C2-NiCr powder spraying coating.The experimental results show that after remelting process,the porosity of both the brushed and not brushed boric acid saturated aqueous solution coating disappeared,their organization has become uniform and fine,the hardness has reduced and wear resistance increased;Besides,there has a transition layer between the coating and substrate,which mainly consist of nickel based solid solution and greatly improved the bonding strength of coating and substrate.With the increasing of Cr3C2-NiCr powder mass fraction,the hardness of coating can be improved and the wear resistance also can increase.