Abstract In order to improve the Ti–6Al–4V (TC4) alloy's defects of low surface hardness and weak high-temperature oxidation resistance, an AlTiVMoNb lightweight refractory high-entropy alloy (RHEA) coating was developed. The AlTiVMoNb coating was successfully deposited on the TC4 substrate by laser cladding. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis showed that the coating and the TC4 substrate are metallurgically bonded, and the coating structure is composed of a single BCC HEA phase, and its lattice constant aXRD = 0.31246 nm, aTEM = 0.31234 nm. Due to the decrease of the d value has a more significant hindering effect on dislocation slip, the decomposition of spinodal in the bcc RHEA coating, the microhardness of the coating is 885.5 HV0.2, which is 2.52 times that of the TC4 substrate, and 1.66 times of the arc-melting alloy. The effect of complex mixed oxides such as Al2O3, TiO2, Al0·2Nb0·2Ti0·6O2, AlMoVO7, and Nb10·7V2·38O32.7 makes the coating continuously oxidized in the air at 800 °C for 120 h, and its oxidation weight is only 10.58% of the TC4 substrate.

中文翻译：

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Ti-6Al-4V表面激光熔覆轻质难熔高熵合金涂层

摘要 为了改善Ti-6Al-4V（TC4）合金表面硬度低、高温抗氧化性弱的缺陷，研制了一种AlTiVMoNb轻质耐火高熵合金（RHEA）涂层。AlTiVMoNb 涂层通过激光熔覆成功沉积在 TC4 基体上。扫描电镜（SEM）、X射线衍射（XRD）和透射电镜（TEM）分析表明涂层与TC4基体呈冶金结合，涂层结构由单一的BCC HEA相组成，其晶格常数 aXRD = 0.31246 nm，aTEM = 0.31234 nm。由于d值的降低对位错滑移有更显着的阻碍作用，bcc RHEA涂层中旋节线的分解，涂层的显微硬度为885.5 HV0.2，为2。是TC4基体的52倍，电弧熔合金的1.66倍。Al2O3、TiO2、Al0·2Nb0·2Ti0·6O2、AlMoVO7、Nb10·7V2·38O32.7等复合混合氧化物的作用使涂层在800℃空气中连续氧化120h，其氧化重量仅占 TC4 底物的 10.58%。