钛合金表面激光熔覆AlB_xCoCrNiTi高熵合金涂层的组织与性能

发布时间：2018-12-21 08:04

【摘要】：目的研究AlB_xCoCrNiTi(x=0、0.5、1)高熵合金涂层的组织及性能,提高钛合金表面硬度及耐磨性。方法采用激光熔覆技术在TC4钛合金表面制备出AlB_xCoCrNiTi高熵合金涂层,运用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、电子探针(EPMA)等材料分析手段,研究了B含量对高熵合金涂层形貌、组织结构、成分的影响,并采用维氏硬度计以及摩擦磨损试验检测了熔覆涂层的硬度和耐磨性能。结果高熵合金涂层与基体的整体结合形貌良好。未添加B的高熵合金涂层主要由BCC相和晶体结构类似(Co,Ni)Ti_2相组成。随着B的加入,高熵合金涂层的晶粒得到细化,BCC相含量增加,(Co,Ni)Ti_2相含量有所减少,且熔覆层原位生成了TiB_2硬质相,TiB_2硬质相含量随B含量的增加而增加。熔覆涂层的硬度和耐磨性与B含量呈正相关关系,AlB_1CoCrNiTi高熵合金涂层的平均显微硬度最大,为814HV,且AlB_1CoCrNiTi高熵合金涂层的磨损量最小,其耐磨性约为未添加B的高熵合金涂层的7倍。结论 B含量的增加,有助于改善AlB_xCoCrNiTi高熵合金涂层的摩擦学性能,AlB_xCoCrNiTi高熵合金涂层有效提高了钛合金表面的硬度及耐磨性能。
[Abstract]:Objective to study the microstructure and properties of AlB_xCoCrNiTi (x0. 0. 5) high entropy alloy coating, and to improve the hardness and wear resistance of titanium alloy. Methods AlB_xCoCrNiTi high entropy alloy coating was prepared on the surface of TC4 titanium alloy by laser cladding technique. Scanning electron microscope (SEM), X) (SEM), X ray diffractometer (XRD), electron probe (EPMA) was used to analyze the material. The effect of B content on the morphology, microstructure and composition of high entropy alloy coatings was studied. The hardness and wear resistance of the coatings were tested by Vickers hardness meter and friction and wear test. Results the morphology of the high entropy alloy coating was good. The high entropy alloy coating without B is mainly composed of BCC phase and crystal structure similar (Co,Ni) Ti_2 phase. With the addition of B, the grain size of high entropy alloy coating was refined, the content of BCC phase increased, the content of (Co,Ni) Ti_2 phase decreased, and the hard phase of TiB_2 was formed in situ. The content of TiB_2 hard phase increased with the increase of B content. The hardness and wear resistance of the cladding coating were positively correlated with B content. The average microhardness of AlB_1CoCrNiTi high entropy alloy coating was the largest (814 HVV), and that of AlB_1CoCrNiTi high entropy alloy coating was the least. The wear resistance of the coating is about 7 times that of the high entropy alloy coating without B addition. Conclusion the increase of B content can improve the tribological properties of AlB_xCoCrNiTi high entropy alloy coating, and the hardness and wear resistance of AlB_xCoCrNiTi high entropy alloy coating can be improved effectively.
【作者单位】：大连理工大学材料科学与工程学院;
【分类号】：TG174.44

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