Silicide-free boride layers were grown on Inconel 718 Ni-based superalloy surface at 850 °C, 950 °C, and 1050 °C for 2, 4, 6 hour by the powder pack-boronizing process using nano-sized B₄C powders. The coatings were examined using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, 3D profilometry, and microhardness measurements. Wear experiments were carried out on untreated and boronized Inconel 718 using a ball-on-disk tribometer under dry sliding conditions at temperatures of 25 °C, 400 °C, and 750 °C. An increase in boronizing temperature and duration increased the thickness and hardness of the obtained boride layers, which resulted in low coefficient of friction values and decreased wear rates. Scanning electron microscopy images of the worn surfaces revealed two-body abrasion as the effective wear mechanism in the untreated samples, and three-body abrasion assisted by microcracking and spalling as the dominant wear mechanism in the boronized samples. A transition from mild to severe wear occurred in the untreated samples, while wear rates remained low in the boronized samples up to 750 °C. In conclusion, boronized Inconel 718 was capable of sustaining its boride layers under 5 N for 1800 m at wear-test temperatures up to 750 °C.

中文翻译：

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硼化Inconel 718的性能和高温干滑磨损行为

通过使用纳米级B ₄的粉末包硼化工艺，在850°C，950°C和1050°C的Inconel 718 Ni基高温合金表面上生长无硅化物的硼化物层2、4、6小时。C粉。使用光学显微镜，扫描电子显微镜，能量分散光谱，X射线衍射法，3D轮廓测定法和显微硬度测量来检查涂层。使用球盘摩擦计在25°C，400°C和750°C的干燥滑动条件下，对未经处理且镀硼的Inconel 718进行了磨损实验。硼化温度和持续时间的增加增加了所获得的硼化物层的厚度和硬度，这导致低的摩擦系数值和降低的磨损率。磨损表面的扫描电子显微镜图像显示，在未经处理的样品中，两件式磨损是有效的磨损机理，而在含硼样品中，以微裂纹和剥落为辅助的三件式磨损是主要磨损机理。未经处理的样品发生了从轻度到严重磨损的转变，而在高达750°C的硼化样品中，磨损率仍然很低。总之，镀铬的Inconel 718能够在高达750°C的磨损测试温度下在5 N下保持1800 m的硼化物层。