Scholarlink

<p>Due to their exceptional tribological properties, specifically under vacuum conditions, MoS<sub>2</sub> solid lubricants have been extensively used in several industries. Since the effectiveness of pure MoS<sub>2</sub> tends to deteriorate in humid and oxygen-containing environments, it is co-deposited by conventional Pb-based compounds to improve its oxidation resistance and tribological performance. However, lead-based compounds are required to be replaced with environmentally-friendly alternatives such as hexagonal boron nitride (hBN) due to their toxicity. Additionally, as extreme temperatures can affect the tribological performance of the coatings, understanding the interfacial phenomenon under realistic service conditions is necessary to mimic the operating conditions of aerospace applications. In this study, MoS<sub>2</sub> coatings with various hBN contents (9.5, 11.5, 13.5, 15.5, and 17.5 wt%) were developed using spray bonding process. The friction behavior was evaluated using a ball-on-flat tribometer at low temperature (i.e., −&#xa0;50&#xa0;°C). Subsequently, the coatings were characterized by ex-situ analysis techniques such as scanning electron microscopy (SEM), focused ion beam (FIB), Raman spectroscopy, and atomic force microscopy (AFM). The results demonstrated that all coatings exhibited significantly lower steady-state friction at −&#xa0;50&#xa0;°C compared to room temperature. A clear distinction was observed between the mechanisms governing the run-in and steady-state stages. The run-in stage was likely influenced by surface morphology and the intrinsic properties of hBN. Increasing hBN content beyond the optimal level led to a prolonged run-in phase and intensified abrasive wear. Conversely, the steady-state performance seemed to be influenced by the formation of a lubricating interfacial ice layer, facilitating low-friction sliding regardless of composition.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Tribological Evaluation of Sustainable Spray-Bonded MoS2/hBN Solid Lubricant at Low Temperature

  • 期刊论文

  • 发表日期：

    2025年7月28日

查看全文
  • Parastoo Fallah,
  • Cara Hensley,
  • Charles J. Beall,
  • Alejandra Islas Encalada,
  • Richard R. Chromik,
  • Rolf Wuthrich,
  • Pantcho Stoyanov

摘要

Due to their exceptional tribological properties, specifically under vacuum conditions, MoS2 solid lubricants have been extensively used in several industries. Since the effectiveness of pure MoS2 tends to deteriorate in humid and oxygen-containing environments, it is co-deposited by conventional Pb-based compounds to improve its oxidation resistance and tribological performance. However, lead-based compounds are required to be replaced with environmentally-friendly alternatives such as hexagonal boron nitride (hBN) due to their toxicity. Additionally, as extreme temperatures can affect the tribological performance of the coatings, understanding the interfacial phenomenon under realistic service conditions is necessary to mimic the operating conditions of aerospace applications. In this study, MoS2 coatings with various hBN contents (9.5, 11.5, 13.5, 15.5, and 17.5 wt%) were developed using spray bonding process. The friction behavior was evaluated using a ball-on-flat tribometer at low temperature (i.e., − 50 °C). Subsequently, the coatings were characterized by ex-situ analysis techniques such as scanning electron microscopy (SEM), focused ion beam (FIB), Raman spectroscopy, and atomic force microscopy (AFM). The results demonstrated that all coatings exhibited significantly lower steady-state friction at − 50 °C compared to room temperature. A clear distinction was observed between the mechanisms governing the run-in and steady-state stages. The run-in stage was likely influenced by surface morphology and the intrinsic properties of hBN. Increasing hBN content beyond the optimal level led to a prolonged run-in phase and intensified abrasive wear. Conversely, the steady-state performance seemed to be influenced by the formation of a lubricating interfacial ice layer, facilitating low-friction sliding regardless of composition.

Graphical Abstract