Effects of nano-NiO addition on the microstructure and corrosion properties of high Nb-TiAl alloy

Powder metallurgy is an important method for preparing TiAl alloys due to its ability to minimize grain size and eliminate compositional segregation. However, the main obstacle to industrial applications is the large number of Kirkendall voids are inevitably introduced in the sintering process because of the diffusion rate discrepancy between Ti and Al atoms. The growth of these cavities in the matrix weakens the oxidation and corrosion resistance under service conditions. Here, a composite with an improved high-temperature antioxidant property and corrosion resistance was fabricated by manipulating chemical reaction, which benefit for higher-temperature applications, such as in aeronautics and aerospace.