Erosion Wear Performance Of TiAlN Based Coatings

As one of the main causes of material spoiled in aerospace,energy,dynamics and other industrial fields,erosion wear have attracted wide attention.To improve the erosion wear resistance,coating are produced on the work-piece surface.TiN coating has been widely applied as resistant coating which could effectively protect the external layer from erosion and increase the service life of the machine parts Recently with the tech advance of technology,TiA1N coating with extreme hardness,wear resistance,oxidation resistance and self-lubricating has gradually replaced the TiN coating.To explore the added elements performance,Si,Cr,C and etc are added to construct nano-composite coating to modify the comprehensive performance of TiAIN coating.Currently,more attention to the oxidation and friction properties of TiAIN composite coating,while less on erosion wear properties.Therefore,the significance of Si and Cr on the erosion wear properties of TiAIN coating was investigated in this studyBy cathodic arc ion plating,the TiAIN,TiASiN and TiAlCrSiN coatings are produced on stainless steel SUS321,.titanium alloy TC4 and cemented carbide YT15 repectively,SEM was used to analyze the morphologies of the original coating as well as that of the eroded coatings;EDS was used to the analysis of the composition of the coatings;XRD was used to examine the phase composition and grain size of the coating;white light interferometer was used to the examine the coating surface roughness;Nano-indentation tester and multifunctional material surface performance tester was used to examine microhardness,elastic modulus,elastic-plastic deformation ability and the binding force between the coating and the substrate Furthermore,with the condition of 90°,450 and 85 m/s,the erosion wear characteristics of the coatings on the three substrates were studied by sand blasting erosion test.In the last,ImageJ was used to the examine the coating erosion wear area.The results are summarized as follows:1.Coating performance:The ranking of the grain sizes was TiAIN>TiAlSiN>TiAlCrSiN.Coatings roughness increased with the rising of particles number on the coating surface,adhesion between the coating and the substrate increased with the decreasing of the grains sizes.The ranking of roughness,hardness and coating substrate adhesion was TiAlCrSiN>TiAlSiN>TiAlN.The substrate material affected the binding force between coating and substrate,the ranking of binding force of the same coating was YT15>SUS321>TC4.2.Coating erosion wear performance:In the 900 impact angle,the ranking of the erosion rate of the coatings coated onto the TC4 and YT15 was TiAlN>TiAlSiN>TiAlCrSiN,while the ranking of the erosion rate of the coatings coated onto the SUS321 was TiAlSiN>TiAlN>TiAlCrSiN.The erosion wear rate decreased with the raising of H,H3/E2 and binding force between coating and substrates.The ranking of the erosion rate of TiAlN coatings coated onto the TC4,YT15 and SUS321 was YT15>SUS321>TC4,The ranking of the erosion rate of TiAlSiN coatings coated onto the TC4,YT15 and SUS321 was SUS321>TC4>YT15.The erosion rate of TiAlCrSiN coating was close to zero.Erosion rate increased with the rising difference between the substrates and the coating.3.Coating erosion wear mechanism:In the 90° impact angle,the erosion wear mechanism of TiAlN coating and TiAlSiN coating coated onto the other three substrates was brittle peeling caused by crack growth except the TiAlSiN coating coated onto YT15 substrates,in which TiAlN coating was massive peeling and TiAlSiN coating was stratified peeling.However,the initial morphologies of the coating had slightly differences,the substrates affected crack generation and propagation speed.TiAlSiN coating coated onto YT15 substrates and TiAlCrSiN coating coated onto three other substrates showed good erosion resistance.4.In the 45° impact angle,erosion mechanism of TiAlN coating and TiAlSiN coating on TC4 substrate showed few differences except for the evident cutting marks.Compared with 90°erosion rate,the 45° erosion rate of TiAlN coating and TiAlSiN coating decreased almost a half than before.