稀土元素的添加对原位生成的Ti-TiC-TiB复合材料抗磨损性能的影响

采用Ti 6Al 4V 5B4C和Ti 6Al 4V 5B4C 1Nd 两种成分的原始粉末, 反应热压后原位生成了Ti TiC TiB复合材料。经过X射线检测, 证明了试验中原位生成反应5Ti+B4C 4TiB+TiC的进行。采用摩擦磨损试验机检测了两种材料的抗磨损性能。通过扫描电子显微镜和电子探针分析了材料的磨损表面。结果表明, 添加稀土元素能提高材料的硬度, 韧性和抗磨损性能。

Effect of rare earth element on wear resistance of in-situ Ti-TiC-TiB composites

Particulate titanium matrix composites, with TiC and TiB reinforcements, have been produced by the reaction hot pressing process with two different starting powder mixtures, namely Ti-6Al-4V-5B 4C and Ti-6Al-4V-5B 4C-1Nd. The existence of B 4C resulted in a combination of TiC+TiB reinforcements. The X-ray diffraction analysis confirmed the reaction of 5Ti+B 4C4TiB+TiC. The wear resistance of in-situ Ti-TiC-TiB composites were investigated. The worn surfaces were observed by means of SEM and EPMA. It shows that the addition of Nd will enhance the wear resistance and hardness. The contribution of rare earth element Nd to the wear resistance lies in that the rare earth element can scavenge oxygen from the titanium matrix, purify the particle interface, enhance the mechanical properties. The decrease of oxygen in matrix results in the increase of toughness and strength of this material. And the plastic deformation ability of the composite can be improved with the increase of toughness. Also, in the process of wear abrasion, Nd oxides distributed in the matrix can reduce the expanding of crack and falling of the abrasive dust. All above shows that the the addition of rare earth element can improve the wear resistance of the in-situ Ti-TiC-TiB composites.