Research on Friction and Wear Resistance of Al-Y Co-deposition Coating on TiAl Alloy Surface

Al-Y co-deposition coatings on TiAl alloy were prepared by pack cementation processes at 930 ℃for 2 h, The scanning electron microscope, X-ray diffraction and energy dispersive spectrometry were employed to investigate the microstructure phase composition of the coatings.The friction and wear behavior of both alloy and coatings sliding against GCr15 were comparatively investigated.The results show that the Al-Y co-deposition coatings prepared at 930 ℃have a composite structure and its thickness is about 50 μm.The coatings and matrix form metallurgical bonding interface, which is mainly composed by Al-riched TiAl₃ outer layer and TiAl₂ inner layer.The wear mechanism of TiAl matrix is ploughing and abrasive, while the Al-Y permeability layer does not exhibit obvious wear, which indicates that the preparation of Al-Y co-deposition coatings can improve the friction and wear resistance of TiAl alloy effectively.