Antifriction characteristics of the magnetron sputtered MoS2 coating of ITER blanket module bolted joints in high vacuum at elevated temperature T =250 °C

IF 3.8 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Vacuum Pub Date : 2024-09-05 DOI:10.1016/j.vacuum.2024.113615

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Abstract

The high values of bolt preload force $F_{a}$ = 90–1200 kN created by the ITER remote handling system can be achieved by using dry coating lubricants such as magnetron sputtering film MoS₂ or WS₂. An expression was determined to estimate the contact pressure based on the number thread turns and the width of the thread contact area in fastened assemblies that used the Spiralock technology. This study investigated the tribological aspects of the magnetron sputtering MoS₂ coating at different thicknesses $h_{c}$ = 6.4–21 μm, contact pressures $p_{a}$ = 20–1200 MPa against the spherical pin (austenitic stainless steel 316L(N)-IG) at elevated temperatures of $T$ = 250 °C in vacuum $p_{v}$ = 10⁻²–10⁻³ Pa. Friction data for “humid” and “dry” rectangular specimens with MoS₂ coating were obtained and compared. With an increase in the thickness of the coating from 6.4 μm to 21 μm, we obtained a distinct stabilization the friction coefficient of the low friction coating for each given regime of wear that diminished from 0.09 ± 0.010 to 0.05 ± 0.005. The wear mechanism of the “layered MoS₂ coating/metal substrate” tribosystem resulted in significant plastic deformation along the sliding direction of the MoS₂ solid lubricant as well as microgrooving and microploughing of the coating by the asperities of the flat contact spot of the spherical pin. Regardless of the type of bolted pair alloys used, we concluded that it is necessary to deposit a low friction coating on both the internal and external threads of the ITER blanket module bolted joints that use the Spiralock technology.

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在高温 T =250 °C 的高真空条件下，热核聚变实验堆毯子模块螺栓连接处磁控溅射 MoS2 涂层的抗摩擦特性

通过使用干涂层润滑剂（如磁控溅射膜 MoS2 或 WS2），ITER 远程处理系统可以获得很高的螺栓预紧力 Fa = 90-1200 kN。根据使用 Spiralock 技术的紧固组件的螺纹圈数和螺纹接触区宽度，确定了估算接触压力的表达式。本研究调查了不同厚度 hc = 6.4-21 μm、接触压力 pa = 20-1200 MPa 的磁控溅射 MoS2 涂层与球形销钉（奥氏体不锈钢 316L(N)-IG）在真空 pv = 10-2-10-3 Pa 的高温（T = 250 °C）条件下的摩擦学问题。随着涂层厚度从 6.4 μm 增加到 21 μm，我们发现低摩擦涂层的摩擦系数在每种特定磨损状态下都明显趋于稳定，从 0.09 ± 0.010 减小到 0.05 ± 0.005。层状 MoS2 涂层/金属基体 "摩擦系统的磨损机制导致了沿 MoS2 固体润滑剂滑动方向的显著塑性变形，以及球形销钉平面接触点表面对涂层的微切和微犁。无论使用哪种螺栓对合金，我们都得出结论，有必要在使用螺旋锁技术的热核实验堆毯子模块螺栓连接的内外螺纹上沉积一层低摩擦涂层。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Vacuum 工程技术-材料科学：综合

CiteScore

6.80

自引率

17.50%

发文量

审稿时长

34 days

期刊介绍： Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences. A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below. The scope of the journal includes: 1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes). 2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis. 3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification. 4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.