To enhance the wear resistance of the Ti6Al4V alloy surfaces, four TiB-reinforced titanium matrix composite (TMC) coatings were in-situ synthesized via laser cladding. This study systematically explored the effects of varying TiB2 contents (5, 15, 25 and 35 wt%) on the microstructure, hardness and wear resistance of the coatings. The results revealed that all TMC coatings contained in-situ synthesized TiB reinforcements, residual TiB2, α-Ti matrix and small amounts of β-Ti. The addition of 5 wt% TiB2 (hypoeutectic region) formed fine eutectic TiB whiskers (TiBw) as reinforcements. At higher TiB2 contents (hypereutectic region), hollow columnar primary TiB and eutectic TiBw were formed. The hardness of the TMC coatings exceeded that of the Ti6Al4V substrate and increased with increasing TiB2 content. Nanoindentation tests indicated that the residual TiB2 and primary TiB had higher hardness and elastic modulus than eutectic TiBw and Ti matrix. The wear resistance of the four TMC coatings was 3–4 times greater than that of the Ti6Al4V substrate, and samples with higher TiB₂ additions are more wear resistant. Abrasive wear was identified as the dominant wear mechanism and the improved wear resistance can be attributed to the reinforcing effects of residual TiB₂ and primary TiB.

中文翻译：

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激光熔覆制备原位 TiB 增强钛基复合涂层：TiB2 含量对组织、硬度和磨损性能的影响


为了提高 Ti6Al4V 合金表面的耐磨性，通过激光熔覆原位合成了四种 TiB 增强钛基复合材料 （TMC） 涂层。本研究系统探讨了不同 TiB2 含量 （5、15、25 和 35 wt%） 对涂层微观组织、硬度和耐磨性的影响。结果表明，所有 TMC 涂层均含有原位合成的 TiB 增强体、残留的 TiB2、α-Ti 基体和少量的 β-Ti。添加 5 wt% TiB2（亚共晶区）形成细共晶 TiB 晶须 （TiBw） 作为增强材料。在较高的 TiB2 含量（过共晶区）下，形成了空心柱状初级 TiB 和共晶 TiBw。TMC 涂层的硬度超过了 Ti6Al4V 基体，并且随着 TiB2 含量的增加而增加。纳米压痕测试表明，残余的 TiB2 和初级 TiB 比共晶 TiBw 和 Ti 基体具有更高的硬度和弹性模量。四种 TMC 涂层的耐磨性是 Ti6Al4V 基材的 3-4 倍，TiB₂ 添加量较高的样品更耐磨。磨粒磨损被确定为主要的磨损机制，耐磨性的提高可归因于残余 TiB₂ 和初级 TiB 的增强作用。