La_2O_3对钛合金表面镍基喷焊涂层组织和性能的影响

Effect of La_2O_3 on Microstructure and Properties of Ni-Based Spray-Welding Coating on Titanium Alloys Substrate

采用火焰喷焊技术在钛合金基体上制备了不加La2O3和加4%(质量分数)La2O3两种镍基涂层,分析了它们的显微组织、合金元素的扩散、显微硬度以及耐磨性能。结果表明:La2O3的加入,改善了涂层合金的流动性和显微组织的均匀性,并使涂层与基体的熔合更加明显,结合性能得到进一步提高;虽然一定程度上减弱了基体Ti元素对喷焊层的强化作用,使表层显微硬度略有下降,但磨损失重却较未加La2O3的喷焊涂层下降了20%。

Two kinds of Ni-base coatings with 0% and 4% La2O3 addition respectively on titanium alloys substrate made by flames spray-welding technique were prepared, and their microstructure, elemental distribution, micro-hardness and tribological properties under dry sliding against steel were studied. The results show that the fluidity of the coating alloys and the uniformity of the microstructure can be improved by adding La2O3, and the fusion between coating and substrate is formed easily, which increases their bonding. The wearing value of the coating with 4% La2O3 is declined by 20% compared with that of the coating without La2O3, although the strengthening of titanium element to spray-welding layer is decreased by adding La2O3, by which the micro-hardness of the surface is reduced.