Influence Of Annealing Temperature On Microstructure And Wear Properties Of The Cr_xAl_yY_1-x-yN Coatings

The CrxAlyY1-x-yN coatings were deposited by closed field unbalanced magnetron sputter iron plating technique in this paper.The coatings were annealed in the vacuum and thermal oxidation environment.The perpormance and micro structure of the samples were analysed before and after annealed by the instruments such as XRD,SEM,AFM,XPS,TEM,micro-hardness tester,nano-indentation,and laser scanning confocal and so on.The effect of coating microstructure stability on wear properties were investigated,combines with the cutting wear experiment and the erosion abrasion experiment.The results show that the coating mechanical properties increased with the rising annealing temperature.Before 450?,oxidized had little effect on the thermal stability.After 450?,oxidized was the main influence factor.The temperature less than 500?,the slower coating grain growth,the smaller degree of recrystallization,the smaller coating phase structure changes,the better stability of the coatings microstructure.When the temperature is 400?,Cr0.768Al0.15Y0.082N coating crystallite size increased 20%,N elements reduced 8.55%,Cr0.636Al0.10Y0.264N coating crystallite size increased 45%,N elements reduced 13.52%.Cr0.768Al0.15Y0.082N coating microstructure stability was stabler than Cr0.636Al0.10Y0.264N coating.Cr0.768Al0.15Y0.082N hardness and fracture toughness fell by 13.3%and 29.4%,respectively.Cr0.636Al0.10Y0.264N hardness and fracture toughness fell by 21%and 41.2%,respectively.The stabler the coating microstructure,the good mechanical properties.The cutting experiment shows that Cr0.768Al0.15Y0.082N coated bits,Cr0.636Al0.10Y0.264N coated bits and HSS bits life were 277,267 and 86,respectively.According to the flank face,uncoated bits had obviously oxidation and adhesion,coated bits wear slightly,the better thermal stability,the less wear flank face.The different annealing temperature can influence the coating wear properties.Cr0.768Al0.15Y0.082N coated bits life fell by 3.6%and 16%,at 300?and 500?.That was positively correlation with the coatings mechanical properties decreased as the temperature increased.The erosive wear experiment shows that the coatings erosive wear performance all decreased with the anneaing temperature increase.Cr0.768Al0.15Y0.082N coating wear depth increased 20%and 60%,erosive wear rate increased 11.5%and 38%at 300? and 500?,respectively.Cr0.636Al0.10Y0.264N coating wear depth increased 36%and 80%,erosive wear rate increased 35%and 43.3%at 300? and 500?,respectively.That coating erosive wear properties at 300? was better than at 500?.The Cr0.768Al0.15Y0.082N and Cr0.636Al0.10Y0.264N coatings erosive wear occurred non brittle peeling and cracking.