水环境下金属基激光熔覆涂层的成形机理及摩擦学性能研究

The laser cladding technology in water environment is the indispensable method to secure the reliability and safety of key components of ocean engineering equipment and it is also a important way to improve integral level of national ocean engineering equipment.However, present study of the forming mechanism and tribological properties of metal laser cladding coating is at a standstill and there are limited foreign literatures that could be used as guidance. Therefore, this project focus on the urgent demand of online maintenance of vulnerable underwater components of ocean engineering equipment and carries out the study of laser cladding formation and tribological mechanism under water environment. This study is to reveal the cladding coating’s mass transfer mechanism between laser, water and materials, confirming the diffusion mechanism of H, O, Cl, S etc. detrimental impurities in cladding coating. Moreover, it also reveals the formation and evolution mechanism of residual stress in laser cladding process, illustrating the evolution regular of organization and forming mechanism of pores and crack etc. defects under multi-physics coupling underwater circumstance, revealing key controlling factors of wear failure mechanism and trobological properties under underwater multifactor coupling environment. Establishing theory system of forming mechanism and tribological behaviors of underwater metal laser cladding, supply the theoretical guidance of on-line maintenance of ocean engineering equipment.

水环境下的激光熔覆技术是保证海洋工程装备水下关键部件服役可靠性及安全性不可或缺的技术手段，也是提高我国海洋工程装备整体水平的重要途径。然而，目前水环境下金属基激光熔覆涂层的成形机理及摩擦学性能的研究一直停滞不前，国内外可供参考的研究成果非常少。因此，本项目拟针对海洋工程装备水下易损部件在线维修的迫切需求，开展水环境下金属材料激光熔覆成形及熔覆层摩擦学的机理研究。重点分析激光/水/材料之间相互作用下的熔覆层传质过程，明确氢、氧、氯、硫等有害杂质在熔覆层中的扩散机制，分析水下激光熔覆过程中残余应力产生及演变机制，阐明水环境中多物理场耦合下的组织演变规律和气孔、裂纹等缺陷形成机理，揭示水环境中多因素耦合作用下的熔覆层磨损失效机理及摩擦学性能关键控性因素，构建较为完善的水下金属材料激光熔覆成形机理及熔覆层摩擦学行为理论体系，为海洋工程关键装备的水下在线维修提供理论指导。

水环境下的激光熔覆技术是保证海洋工程装备水下关键部件服役可靠性及安全性不可或缺的技术手段，也是提高我国海洋工程装备整体水平的重要途径。本项目针对海洋工程装备水下易损零部件在线维修的迫切需求，对水环境下金属基激光熔覆涂层的成形机理及摩擦学性能开展了深入研究，以期为海洋工程关键装备水下在线维修提供理论指导。项目按照预期研究计划执行，研究过程顺利，已经完成的主要研究内容有：搭建了水环境下激光熔覆试验平台，采用FLUENT模拟软件对熔池近表层的溶液相变行为进行模拟分析，结合水下激光熔覆层表面状态检测，分析了水下激光熔覆过程中近固壁面的空化泡的溃灭过程及高速射流的产生及防护机制，明确了水环境下激光熔覆层内部缺陷分布规律及高速空化射流诱导缺陷形成机理，分析了熔覆层内部杂质元素分布状态及传质规律；通过气幕覆层营造、材料表面修饰、超声辅助等方式优化水下激光熔覆层的成形质量，明确了在水环境中激光熔覆层的成形调控机理及工艺优化原则；通过探究高盐海水环境下熔覆层的组织演变、硬度及应力分布状态，揭示了超快冷速环境下水下熔覆层的组织淬硬化行为、界面结合特性及应力分布规律；通过活性元素、稀土元素及氟化物多元添加的方式调控水下熔覆层海水环境下的腐蚀及摩擦学性能，揭示了海水环境下激光熔覆层组织演变及表面腐蚀及摩擦性能调控机理。本项目深入揭示了水环境下金属基激光熔覆的成形机理、组织演变及其与摩擦学性能的相互作用关系，构建较为完善的水下金属基激光熔覆涂层成形和摩擦学性能调控理论体系，为海洋工程装备金属部件水下在线维修提供具有重要的指导意义。基于上述研究，申请国家发明专利15项，授权8项；完成相关学术论文37篇，其中已发表SCI论文33篇、EI论文4篇；获得黑龙江省科学技术奖二等奖1项，黑龙江省高校科学技术奖三等奖1项。