Ion Carbonitriding of TiAl Based Alloy and Its Wear Resistance

Nitriding and carbonizing were combined to increase the surface wear resistance and high temperature oxidation resistance of TiAl based alloy. Thus glowing ion carbonitriding was used to modify the TiAl based alloy surface. The correlation among the phase structure and processing parameters and the thickness, hardness, and antiwear behavior of the carbonitriding layer on TiAl based alloy was studied. The phase composition of the carbonitriding layer was analyzed using X-ray diffraction. The results showed that the carbonitriding layer was composed of carbonitride and transition layer compound. The thickness of the carbonitriding layer gradually increased with increasing process temperature and time. Moreover, the surface hardness and wear resistance of the TiAl based alloy were greatly increased by ion carbonitriding, which was attributed to the formation of the hard ceramic phases including TiC, TiN, AlTi_3, Al_2O_3, in the carbonitriding layer.