Effect of Al content on 1200 °C steam oxidation behavior of Cr-based coatings on TZM alloy

In this paper, the 1200 °C high temperature steam oxidation behavior of Cr-based coatings with different Al content (0, 15 at%, 30 at%, 50 at%) deposited on titanium-zirconium-molybdenum (TZM) alloy has been investigated. The oxidation resistance of TZM alloy is significantly increased by the Cr-based coatings. The Cr70Al30 coating exhibits the best performance due the protectiveness of a triple oxide layer formed on coating surface, including outer Al2O3 and Cr2O3 mixed layer, intermediate Cr-rich oxide (Cr2O3) layer and inner Al-rich oxide (Al2O3) layer. The effect of Al content on the oxidation resistance of Cr-based coatings is discussed in detail.