Abstract:Si-Al-Y2O3 co-deposition coatings on TiAl alloy were prepared by pack cementation processes at 1000, 1050, 1100℃ and 1150℃ for 4h, scanning electron microscope (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) were employed to investigate the surface morphologies, microstructures and phase constitutions of the coatings. The results show that the Si-Al-Y co-deposition coatings have multi layer structure. All the coatings are mainly composed of a TiAl2 and γ-TiAl inner layer, and an Al rich inter-diffusion zone; the phase constituents of outer layers and middle layers of the coatings change with increasing co-deposition temperatures. The outer layer of the coating prepared at 1000℃ for 4h is composed of TiAl3. However, the constituent phases change into TiSi2 in the out layer, and the middle layer is composed of (Ti, X)5Si4 and (Ti, X)5Si3(X represents Nb and Cr) for coating prepared at 1050℃ for 4h. The coatings prepared at 1100℃ and 1150℃ for 4 h have same layer structure, and (Ti, X)5Si4,(Ti, X)5Si3 phases are detected in the outer layer of the coating prepared at 1100℃, and (Ti, X)5Si3 phases are detected in the outer layer of the coating prepared at 1100℃. In the four kinds of (1000, 1050, 1100℃ and 1150℃) temperatures investigated, the coating prepared at 1050℃ for 4h have a denser and thicker layer, so it is selected for Si-Al-Y co-deposition.
李涌泉, 谢发勤, 吴向清, 姚小飞. 温度对TiAl合金表面Si-Al-Y共渗层组织结构的影响[J]. 材料工程, 2014, 0(6): 22-27.
LI Yong-quan, XIE Fa-qin, WU Xiang-qing, YAO Xiao-fei. Effect of Temperature on Microstructures of Si-Al-Y Co-deposition Coatings on TiAl Alloy. Journal of Materials Engineering, 2014, 0(6): 22-27.
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