摘要
在304不锈钢基体上使用冷喷涂法和电镀法制备Cr涂层,通过分析冷喷涂Cr涂层表面微观形貌、截面显微组织及纳米力学性能,阐明Cr粉末颗粒的碰撞沉积行为及Cr涂层沉积机制。结果表明:电镀Cr涂层存在大量纵向裂纹,冷喷涂Cr涂层与基体之间的结合界面呈现不规则形态,但界面结合紧密且无明显缺陷。同时,Cr涂层表面存在大量凹坑,且近表面区域表现为细小的等轴晶。该区域的纳米硬度较未变形Cr粉末颗粒提升了41.37%~62.17%,表明后续粉末颗粒在已沉积Cr涂层上产生由喷丸作用引起的加工硬化效应,使后续粉末颗粒与已沉积涂层之间难以发生协同塑性变形,从而降低了进一步沉积的可行性。基于Cr涂层微观形貌及梯度纳米硬度分布特征,提出Cr涂层在304不锈钢上的沉积机制为基体氧化膜的破碎、首层涂层的形成及其在喷丸强化作用下表面微观形貌的演变过程。
The Cr coatings are fabricated on 304 stainless steel substrates using cold spray and electroplating methods.The particle deposition behavior and coating formation mechanism of Cr are clarified by analyzing the surface morphology,cross-sectional microstructure,and nanomechanical properties of the cold-sprayed Cr coatings.The results show that the electroplated Cr coating contains numerous vertical cracks,while the cold-sprayed Cr coating exhibits an irregular but compact and defect-free interface with the substrate.In addition,the surface of the cold-sprayed coating presents a large number of craters,and the near-surface region consists of fine equiaxed grains.The nanohardness in the region increases by 41.37%-62.17%compared with that of undeformed Cr particles,indicating that subsequent particles produce work hardening due to shot-peening effects upon impacting the pre-deposited coating.The hardening hinders cooperative plastic deformation between incoming particles and the existing coating,thereby reducing the feasibility of further deposition.Based on the surface morphology and the gradient distribution of nanohardness,the deposition mechanism for Cr coatings on 304 stainless steel is proposed,involving the disruption of the substrate’s oxide film,the formation of the initial coating layer,and the surface morphological evolution induced by shot-peening strengthening.
作者
万文鹏
黄春杰
许爱军
罗杰
王罗
傅硕
徐雅欣
李文亚
WAN Wenpeng;HUANG Chunjie;XU Aijun;LUO Jie;WANG Luo;FU Shuo;XU Yaxin;LI Wenya(State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Shaanxi Key Laboratory of Friction Welding Technologies,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Changsha 5712 Aircraft Industry Co.,Ltd.,Changsha 410114,China;Suzhou Tianhe China Power International Engineering Technology Co.,Ltd.,Suzhou 215027,Jiangsu,China;State Key Laboratory of Nuclear Power Safety Technology and Equipment,China Nuclear Power Engineering Co.,Ltd.,Shenzhen 518172,Guangdong,China)
出处
《材料工程》
北大核心
2026年第3期229-235,共7页
Journal of Materials Engineering
基金
核电安全技术与装备全国重点实验室开放基金资助(SKL-2024-TS-01)
西北工业大学凝固技术全国重点实验室课题资助(2025-DXZX-ZC-02)
中央高校基本科研业务费专项(G2024KY05107)。
关键词
冷喷涂
Cr涂层
涂层成形机制
微观组织
纳米硬度
cold spraying
Cr coating
coating forming mechanism
microstructure
nanohardness
