High-Temperature Oxidation Behavior of Double Glow Plasma Cr-W Alloying Layer on γ-TiAl Alloy Surface

Cr-W alloying layer was prepared on TiAl alloy by using the double glow plasma surface alloying technology(DGP), and the high temperature oxidation behavior of the alloying layer was tested by SEM, EDX, XRD and high temperature oxidation experiment. The results show that the surface morphology of the Cr-W alloying layer is smooth and the microstructure is uniform. The alloying layer closely connects with the matrix, without holes, cracks and other defects on the joint. The Cr-W alloying layer at high temperature can form a protective film to reduce the rate of oxidation effectively. The anti-oxidantion capacity of the alloying layer is significantly improved, and the oxidation weight gain is lower than that of the matrix. With the increase of the oxidation temperature, the oxidation weight gain of the alloying layer increases significantly and the oxidation mechanism is unchanged. In the oxidation process, the internal diffusion of Cr and W is found, together with the external diffusion of Ti and Al.