Benefits of passive element Ti to the resistance of AlCrFeCoNi high-entropy alloy to corrosion and corrosive wear
Benefits of passive element Ti to the resistance of AlCrFeCoNi high-entropy alloy to corrosion and corrosive wear
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DOI：
10.1016/j.wear.2021.204231
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发表时间：
2021-12
期刊：
影响因子：
5
通讯作者：
M. Wu;R. C. Setiawan;D.Y. Li
中科院分区：
文献类型：
--
作者：
M. Wu;R. C. Setiawan;D.Y. Li
研究了5元AlCrFeCoNi和6元AlCrFeCoNiTi0.5高熵合金(HEAs)在3.5wt%NaC l和HCl(pH=0.3)溶液中与Si3N4球的摩擦磨损行为。分析了添加钛对HEA的组织、硬度、磨损和腐蚀的影响。结果表明，AlCrFeCoNiTi0.5具有较高的硬度，这主要归因于固溶强化和沉淀强化。AlCrFeCoNiTi0.5与直径分别为4 mm和6 mm的Si3N4球在干燥条件下的磨损量明显低于AlCrFeCoNi。钛的加入还提高了HEA的耐腐蚀性，尤其是抗点蚀性能，表现为降低了Icorrand Ibitand，提高了Rp和RCT。这是由于钛在钝化膜的形成过程中起到了保护作用，阻碍了点缺陷的输运和钝化膜的击穿。原子力显微镜(AFM)测量的表面电势表明，AlCrFeCoNiTi0.5中相邻域之间的差异较小，这应该只会导致较弱的局部电偶合。因此，添加钛有助于抑制对HEA的点蚀攻击。AlCrFeCoNiTi0.5合金在腐蚀磨损过程中，对偶球的溶液和尺寸对其性能有较大影响。阐明了钛在破坏过程中对HEA性能产生有益影响的机理。
Wear behaviors of 5-element AlCrFeCoNi and 6-element AlCrFeCoNiTi0.5high entropy alloys (HEAs) against the Si3N4ball respectively in 3.5 wt% NaCl and HCl (pH = 3) solutions were investigated. The role of the Ti addition in affecting microstructure, hardness, wear and corrosion of the HEA was analyzed. Results showed that the AlCrFeCoNiTi0.5exhibited higher hardness, ascribed to the solid solution strengthening and precipitation strengthening. The wear loss of AlCrFeCoNiTi0.5is markedly lower than that of AlCrFeCoNi under the dry condition against Si3N4balls of 4 mm and 6 mm in diameter, respectively. The Ti addition also improved the corrosion resistance, especially the pitting corrosion resistance, of the HEA, evidenced by lowered Icorrand Ipitand elevated Rpand Rct. This was attributed to the contribution of Ti in the formation of a more protective passive film, which impeded the point defect transport and passive film breakdown. The surface potential measured by means of atomic force microscopy (AFM) shows a smaller difference between adjacent domains in AlCrFeCoNiTi0.5, which should only result in weak local galvanic coupling. Thus, the Ti addition helps suppress the pitting attack to the HEA. The solutions and size of counterpart ball have large influences on the performance of AlCrFeCoNiTi0.5during corrosive wear. Efforts are made to clarify the mechanism for the beneficial role of Ti addition in affecting the performance of the HEA during the destructive processes.