Effect of nanocrystallization on hot corrosion resistance of Ti-48Al-8Cr-2Ag alloy in molten salts
(1. Department of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China;
2. State Key Laboratory for Corrosion and Protection, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016,China;
3. Shenyang National Laboratory for Materials Sciences,Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
2. State Key Laboratory for Corrosion and Protection, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016,China;
3. Shenyang National Laboratory for Materials Sciences,Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: Magnetron-sputter deposition was used to produce Ti-48Al-8Cr-2Ag coating on a cast alloy substrate with the same composition. Hot corrosion was carried out in molten (Na,K)2SO4 and Na2SO4+NaCl at 900 ℃. The sputtered nanocrystalline coating shows much better hot-corrosion resistance in molten (Na,K)2SO4 as a result of the formation of a continuous and compact Al2O3 scale. The nanocrystallization of TiAlCrAg alloy prolongs the incubation of breakaway corrosion and improves the hot-corrosion resistance of TiAlCrAg alloy in molten Na2SO4+NaCl. The relevant corrosion mechanism was discussed.
Key words: Ti-48Al-8Cr-2Ag alloy; magnetron sputter; nanocrystallization; hot corrosion; oxide scale