NiAlCoCrFeTi系高熵高温合金的摩擦学性能研究

采用真空电弧熔炼技术制备了NiAlCoCrFeTi (HESA-1)和NiAlCoCrFeTiTaMoW (HESA-2)这2种典型的高熵高温合金，研究了其微观组织、力学性能和25~900 ℃的摩擦学性能. 结果表明：2种合金均由无序面心立方晶格(FCC)结构的γ相和有序FCC结构的γ´相组成；γ相使该合金具有良好的塑性和韧性，γ´相赋予其较高的强度和硬度. 25~900 ℃，2种合金的摩擦系数和磨损率均随温度的升高而呈下降趋势. 25 ℃时，磨损机制主要为磨粒磨损，摩擦系数较大且磨损率较高. 400 ℃以上时，在摩擦氧化和热氧化的作用下，磨痕表面开始形成1层不连续的氧化物釉质层，摩擦系数和磨损率均有所降低. 当温度达到900 ℃时，磨痕表面上形成了1层光滑且致密的氧化物釉质层，该釉质层具有良好的减摩抗磨作用，使HESA-1和HESA-2这2种合金的摩擦系数分别降至0.26和0.25，磨损率分别降至13.3×10−6 和8.0×10−6 mm3/(N·m). 在高温摩擦过程中，合金表面的Al、Cr、Ni和Co等元素在摩擦热和环境热的共同作用下发生氧化并形成1层致密的氧化物釉质层，使2种合金均具有优良的高温摩擦学性能. 高温下，含难熔金属元素的HESA-2合金具有更高的强度和硬度，使其高温抗磨损性能优于HESA-1合金.

Two typical high-entropy high-temperature alloys, NiAlCoCrFeTi (HESA-1) and NiAlCoCrFeTiTaMoW (HESA-2), were prepared via vacuum arc melting technology. Their microstructures, mechanical properties and tribological properties at temperatures ranging from 25 °C to 900 °C were investigated. The results show that both alloys consist of a γ phase with disordered face-centered cubic (FCC) lattice structure and a γ' phase with ordered FCC structure; the γ phase endows the alloys with excellent plasticity and toughness, while the γ' phase imparts high strength and hardness to them. Over the temperature range of 25–900 °C, both the friction coefficients and wear rates of the two alloys decrease with increasing temperature. At 25 °C, the wear mechanism is mainly abrasive wear, with relatively high friction coefficient and wear rate. Above 400 °C, under the combined effects of tribo-oxidation and thermal oxidation, a discontinuous oxide glaze layer begins to form on the worn surface, leading to reductions in both the friction coefficient and wear rate. When the temperature reaches 900 °C, a smooth and dense oxide glaze layer forms on the worn surface. This glaze layer exhibits excellent anti-friction and wear-resistant performance, reducing the friction coefficients of HESA-1 and HESA-2 to 0.26 and 0.25, respectively, and their wear rates to 13.3×10−6 and 8.0×10−6 mm3/(N·m), respectively. During high-temperature friction, elements such as Al, Cr, Ni and Co on the alloy surface undergo oxidation under the combined action of frictional heat and ambient heat, forming a dense oxide glaze layer, which endows both alloys with excellent high-temperature tribological properties. At high temperatures, HESA-2 alloy containing refractory metal elements exhibits higher strength and hardness, resulting in better high-temperature wear resistance than HESA-1 alloy.

搜集汇总

背景与挑战

背景概述

该数据集研究了NiAlCoCrFeTi系高熵高温合金在不同温度下的摩擦学性能，发现高温形成的氧化物釉质层能显著降低摩擦系数和磨损率。研究通过真空电弧熔炼技术制备合金样品，并系统分析了其微观组织与力学性能的关系。