LAUSR

Abstract A multilayered AlCrTiSiN coating, mainly consisting of an inner AlCrN buffer layer and an outermost AlCrTiSiN layer, was deposited on the 316L austenite stainless steel (ASS), and then isochronally annealed at below 900 °C. The effects of microstructures on adhesion strength and corrosion resistance of the AlCrTiSiN coatings annealed at different temperatures were systematically investigated in 3.5 wt% NaCl solution and 10 wt% H2SO4 solution. The results show that the Ti addition notably retards spinodal decomposition of the AlCrTiSiN coating compared with AlCrSiN one. The phase structures of the AlCrTiSiN layer vary from fcc-AlMeN (Me = Cr or/and Ti) solid solution to rich-Me and rich-Al fcc-domains, and then to hcp-AlN, Cr, Cr2N and TiN. Surface defects of the coatings decrease notably with the increasing annealing temperature. Annealing at above 800 °C leads to a notable loss in adhesion strength due to the formation of brittle Cr2N, hcp-AlN and σ-CrFe of the buffer layer. The coatings annealed at 800 °C show the best corrosion resistance in 3.5 wt% NaCl solution, whereas the ones annealed at 700 °C reveals best corrosion resistance in 10 wt% H2SO4 solution.