Abstract

High-entropy alloys (HEAs) have been deliberated as potential matrix material for self-lubricating composites due to their excellent mechanical properties. In this study, the Al_0.2Co_1.5CrFeNi_1.5Ti HEA powders with a face-centered cubic structure were prepared by mechanical alloying. Then, the alloyed HEA powders were sintered at 700 °C to achieve sprayed powder with suitable particle size. Next, the Al_0.2Co_1.5CrFeNi_1.5Ti HEA-based composite coating was plasma sprayed on carbon steel by combining Ag. Dry friction experiment was applied in order to investigate the tribological properties of HEA − Ag composite coating at temperatures ranging from 25 to 750 °C. The composite coating that was sprayed with HEA − Ag exhibited a low friction coefficient (0.253) and a relatively low wear rate (8.9 × 10⁻⁶ mm³/Nm) at 750 °C. Furthermore, the HEA + Ag coating obtained an increased hardness and superior tribological properties after high temperature annealing. The dense, continuous oxide layer that was formed tightly covered the coating surface and combined with the lubrication of Ag clusters to protect the underlying materials from wear loss at high temperatures.

中文翻译：

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25至750°C等离子喷涂Al 0.2 Co 1.5 CrFeNi 1.5 Ti-Ag复合涂层的组织和摩擦学性能

摘要

高熵合金（HEA）由于其优异的机械性能已被考虑作为自润滑复合材料的潜在基质材料。在这项研究中，通过机械合金化制备了具有面心立方结构的Al _0.2 Co _1.5 CrFeNi _1.5 Ti HEA粉末。然后，将合金化的HEA粉末在700°C的温度下烧结，以获得具有合适粒度的喷涂粉末。接下来，Al _0.2 Co _1.5 CrFeNi _1.5通过结合Ag将Ti HEA基复合涂层等离子喷涂到碳钢上。为了研究HEA-Ag复合涂层在25至750°C的温度下的摩擦学性能，进行了干摩擦实验。喷涂HEA-Ag的复合涂层在750°C时具有较低的摩擦系数（0.253）和相对较低的磨损率（8.9×10 ^-6  mm ³ / Nm）。此外，HEA + Ag涂层在高温退火后具有更高的硬度和优异的摩擦学性能。形成的致密，连续的氧化物层紧紧覆盖了涂层表面，并与Ag团簇的润滑相结合，以保护下面的材料免受高温下的磨损损失。