Laser surface treatment of WSC coatings for selective crystallization of the TMD phase

IF 5.3 2区材料科学 Q1 MATERIALS SCIENCE, COATINGS & FILMS

Surface & Coatings Technology Pub Date : 2025-06-16 DOI:10.1016/j.surfcoat.2025.132403

Jorge Caessa , Albano Cavaleiro , E.L. Silva , Todor Vuchkov

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引用次数: 0

Abstract

Low friction in WSC coatings—comprising a WS₂ phase embedded within an amorphous carbon matrix—relies on sliding-induced WS₂ crystallization, process that typically requires prolonged running-in periods.

Laser treatments can alternatively induce WS₂ crystallization prior to sliding, without compromising the structural integrity of the amorphous carbon matrix. However, current laser processing approaches are often imprecise and lack systematic optimization of the process parameters, as most research focuses on material ablation and topography modification, rather than structural transformations.

This study systematically optimized the laser treatment of WSC coatings (∼50 at. % C) under near-ideal conditions (WSCIR1-WSCIR3) to identify key variables and thresholds governing WS₂ phase crystallization and amorphous carbon graphitization. We adjusted laser parameters—average power, pulse duration, and repetition rate—and refined derived quantities such as energy per pulse, fluence, and power density.

Geometrical, structural, and mechanical changes to the WSC coatings were then analyzed using optical microscopy, profilometry, ball cratering, Raman spectroscopy, X-ray diffraction, and nanoindentation. Increased laser exposure darkened and expanded the dimensions (diameter, height, depth) of the treated zones, and enhanced WS₂ crystallization—while maintaining coating hardness and elastic modulus due to minimal amorphous carbon graphitization.

Our findings establish critical thresholds and present a precise, scalable pathway for engineering WSC coatings, potentially eliminating the need for extended running-in periods.

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激光表面处理WSC涂层的TMD相选择性结晶

WSC涂层（包括嵌入在无定形碳基体中的WS2相）的低摩擦依赖于滑动诱导的WS2结晶，这一过程通常需要长时间的磨合期。激光处理可以在滑动之前诱导WS2结晶，而不影响非晶碳基体的结构完整性。然而，目前的激光加工方法往往不精确，缺乏系统的工艺参数优化，因为大多数研究都集中在材料烧蚀和形貌改变上，而不是结构转变。本研究系统地优化了WSC涂层的激光处理（~ 50 at）。% C)在近理想条件下（WSCIR1-WSCIR3），以确定控制WS2相结晶和非晶碳石墨化的关键变量和阈值。我们调整了激光参数——平均功率、脉冲持续时间和重复率——并改进了衍生量，如每脉冲能量、影响和功率密度。然后使用光学显微镜、轮廓术、球孔、拉曼光谱、x射线衍射和纳米压痕分析了WSC涂层的几何、结构和力学变化。增加激光曝光会使处理区域变暗并扩大尺寸（直径、高度、深度），并增强WS2结晶，同时由于最小的非晶碳石墨化，保持涂层硬度和弹性模量。我们的研究结果建立了临界阈值，并为工程WSC涂层提供了精确、可扩展的途径，有可能消除延长磨合期的需要。

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

Surface & Coatings Technology 工程技术-材料科学：膜

CiteScore

10.00

自引率

11.10%

发文量

921

审稿时长

19 days

期刊介绍： Surface and Coatings Technology is an international archival journal publishing scientific papers on significant developments in surface and interface engineering to modify and improve the surface properties of materials for protection in demanding contact conditions or aggressive environments, or for enhanced functional performance. Contributions range from original scientific articles concerned with fundamental and applied aspects of research or direct applications of metallic, inorganic, organic and composite coatings, to invited reviews of current technology in specific areas. Papers submitted to this journal are expected to be in line with the following aspects in processes, and properties/performance: A. Processes: Physical and chemical vapour deposition techniques, thermal and plasma spraying, surface modification by directed energy techniques such as ion, electron and laser beams, thermo-chemical treatment, wet chemical and electrochemical processes such as plating, sol-gel coating, anodization, plasma electrolytic oxidation, etc., but excluding painting. B. Properties/performance: friction performance, wear resistance (e.g., abrasion, erosion, fretting, etc), corrosion and oxidation resistance, thermal protection, diffusion resistance, hydrophilicity/hydrophobicity, and properties relevant to smart materials behaviour and enhanced multifunctional performance for environmental, energy and medical applications, but excluding device aspects.