Titanium alloys have high specific strength and excellent high temperature and corrosion resistance but low hardness and poor wear resistance. In this study, TiC-reinforced Ti2Ni/Ti5Si3 eutectic matrix composite coatings were fabricated on TC21 titanium alloy substrates by laser cladding. The phase composition and microstructure of the coating with micro- or nano-sized SiC addition as well as the microhardness and wear resistance of the coatings were evaluated. The analysis showed that the composite coatings were mainly made up of TiC, TiNi, Ti5Si3, and Ti2Ni phases, the TiC phase being distributed on the eutectic Ti2Ni/Ti5Si3 phase. The coatings with nano-SiC addition exhibited better coating quality, and higher microhardness and wear resistance than the coatings with micro-SiC addition. The better properties of the coating with nano-SiC addition were mainly attributed to the larger amount of the TiC hard-reinforcing phase and a more compact microstructure. The predominant wear mechanism of the coating with micro-SiC addition was adhesive wear, while it was abrasive wear for the coating with nano-SiC addition. This study should provide an insight into the development of Ti2Ni/Ti5Si3 eutectic matrix coatings.

中文翻译：

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TiC增强Ti2Ni/Ti5Si3共晶基激光熔覆复合涂层的组织与性能

钛合金比强度高，耐高温、耐腐蚀，但硬度低，耐磨性差。在这项研究中，通过激光熔覆在 TC21 钛合金基体上制备了 TiC 增强的 Ti2Ni/Ti5Si3 共晶基复合涂层。对添加微米级或纳米级 SiC 的涂层的相组成和微观结构以及涂层的显微硬度和耐磨性进行了评估。分析表明，复合涂层主要由TiC、TiNi、Ti5Si3和Ti2Ni相组成，TiC相分布在共晶Ti2Ni/Ti5Si3相上。添加纳米碳化硅的涂层比添加微碳化硅的涂层表现出更好的涂层质量、更高的显微硬度和耐磨性。添加纳米 SiC 的涂层具有更好的性能主要归因于更大量的 TiC 硬质增强相和更致密的微观结构。添加微碳化硅涂层的主要磨损机制为粘着磨损，添加纳米碳化硅涂层的磨损机制为磨粒磨损。这项研究应该为 Ti2Ni/Ti5Si3 共晶基体涂层的发展提供见解。