Preparation of TiAl3-Al composite coating by cold spraying
(State Key Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Science,
Shenyang 110016, China)
Shenyang 110016, China)
Abstract: TiAl3-Al coating was deposited on orthorhombic Ti2AlNb alloy substrate by cold spraying with the mixture of pure Al and Ti as the feedstock powder at a fixed molar ratio of 3׃1 when the spraying distance, gas temperature and gas pressure for the process were 10 mm, 250 ℃ and 1.8 MPa, respectively. The as-sprayed coating was then subjected to heat treatment at 630 ℃ in argon atmosphere for 5 h at a heating rate of 3 ℃/min and an argon gas flow rate of 40 mL/min. The obtained TiAl3-Al composite coating is about 212 μm with a density of 3.16 g/cm3 and a porosity of 14.69% in general. The microhardness and bonding strength for the composite coating are HV525 and 27.12 MPa.
Key words: cold spraying; TiAl3-Al composite coating; orthorhombic Ti2AlNb alloy; high temperature oxidation