摘要
爆炸加工技术凭借其瞬时高温、高压及高能率特性,在金属、陶瓷等材料的成形、焊接及涂层制备领域展现出独特优势。本文聚焦于爆炸压焊,并结合扩散烧结技术,系统研究了碳化钨钴(WC-Co)涂层的制备机理与性能。通过机械合金化法制备WC-Co复合粉末(钴粉与碳化钨质量比19∶1),采用爆炸压焊—扩散烧结4步工艺(预压、还原烧结、爆炸压焊、扩散烧结),在不锈钢基体上成功制备出高致密度WC-Co涂层。利用扫描电子显微镜(SEM)、能谱(EDS)分析及电子背散射衍射(EBSD)等表征手段,揭示了涂层的微观结合机制与元素分布特性。实验结果表明,爆炸压焊过程中,颗粒间通过摩擦焊接、爆炸焊接及液相烧结实现结合,其中液相烧结占主导地位,其成因源于高压下颗粒摩擦生热。界面处Co、Fe与WC发生显著元素扩散,晶粒因高应变与再结晶行为显著细化。力学性能测试显示,涂层剪切强度大于35 MPa,断裂模式为脆性断裂,主要归因于钴颗粒界面结合面韧性不足。
Explosive processing technology exhibits unique advantages in the forming,welding,and coating preparation of metals,ceramics,and other materials due to its instantaneous high-temperature,high-pressure,and high-energy rate characteristics.This study focused on explosive compaction welding combined with diffusion sintering technology to systematically investigate the preparation mechanism and properties of tungsten carbide-cobalt(WC-Co)coatings.WC-Co composite powder(with a cobaltto-tungsten carbide mass ratio of 19∶1)was prepared via mechanical alloying.A four-step process,explosive compaction welding followed by diffusion sintering(pre-compaction,reduction sintering,explosive compaction welding,and diffusion sintering),was employed to successfully fabricate a high-density WC-Co coating on a stainless steel substrate.The coating's microstructural bonding mechanism and elemental distribution were revealed by characterization techniques such as scanning electron microscopy(SEM),energydispersive spectroscopy(EDS),and electron backscatter diffraction(EBSD).Experimental results indicated that during explosive compaction welding,particle bonding was achieved through friction welding,explosive welding,and liquid-phase sintering,with liquidphase sintering being the dominant mechanism due to frictional heating under high pressure.Significant elemental diffusion of Co,Fe,and WC occurred at the interface.Grain refinement was attributed to high strain and recrystallization behavior.Mechanical tests showed that the coating exhibited a shear strength exceeding 35 MPa,with a brittle fracture mode primarily caused by insufficient interfacial bonding strength between cobalt particles.
作者
刘中枢
朱桂春
曾翔宇
郭豪杰
孟令鹤
李雪交
陈翔
LIU Zhongshu;ZHU Guichun;ZENG Xiangyu;GUO Haojie;MENG Linghe;LI Xuejiao;CHEN Xiang(State Key Laboratory of Precision Blasting,Hubei(Wuhan)Institute of Explosion and Blasting Technology,School of Digital Construction and Blasting Engineering,Jianghan University,Wuhan 430056,Hubei,China;An-hui Provincial New-type Explosive Materials and Blasting Technology Engineering Research Center,Anhui Univer-sity of Science and Technology,Huainan 232000,Anhui,China)
出处
《江汉大学学报(自然科学版)》
2025年第6期30-38,共9页
Journal of Jianghan University(Natural Science Edition)
基金
国家自然科学基金青年科学基金项目(NSFC12302436)
安徽省新型爆炸材料与爆破技术工程研究中心开放课题项目(AHBP2023B-11)。
关键词
爆炸压焊
碳化钨钴涂层
电子显微镜
能谱分析
电子背散射衍射
剪切强度
explosion welding
tungsten carbide-cobalt coatings
electron microscopy
energy dispersive spectroscopy
electron backscatter diffraction
shear strength
