基于超音速激光沉积的金属增材制造技术基础研究

High-end equipment manufacturing is an important development direction in the future of Zhejiang province and our country. However, there are some issues which restrict the development of high-end equipment manufacturing industry in China, such as weak fundamental research, lack of advanced manufacturing techniques, tremendous energy/resource consumption, and so on. Additive manufacturing (3D printing) has become a key technology to achieve this breakthrough. However, low efficiency, high cost and difficult quality control are the main bottleneck at this stage for 3D printing to be wide industrial application..Supersonic laser deposition technology is a coating preparation method which combines the advantages of cold spraying and laser such as high deposition efficiency, low heat input, low cost and high performance, having great potential in metal additive manufacturing. On the basis of our previous research and together with foreign research group, this project aims to reveal the coupling relationship between supersonic momentum field and high energy laser beam temperature field, to elucidate the bonding mechanism between solid particles and interlayer, and to obtain process quality control method for additive manufacturing. The implementing of this project is expected to break the technical bottleneck of existing metal additive manufacturing technologies and realize high efficiency, high quality, low cost intelligent metal additive manufacturing of the key parts of high-end equipment by supersonic laser deposition, finally providing key technical support for Zhejiang province and China’s manufacturing industry upgrading and new economic development.

高端装备制造是浙江省和国家未来发展的重要方向，但目前我国存在基础研究薄弱、先进制造手段缺乏、制造过程能耗大等问题，严重制约了该产业的发展。增材制造(3D)打印成为实现这一突破的关键技术，然而由于存在着效率低、成本高及质量难于控制三大难题，成为现阶段实现工业化应用的主要瓶颈。.超音速激光沉积技术结合冷喷涂和激光熔覆的各自优势，具有沉积效率高、温度低、成本低、性能高等优点，是一种极具潜力的新型金属增材制造技术。本项目拟在前期研究基础上，联合国内外优势力量，通过对超音速动量场与高能激光束温度场等多能量场耦合关系、沉积涂层颗粒及沉积层固态结合机理以及增材成形过程中缺陷及应力的产生机制等科学问题的研究，获得实现增材制造必需的工艺及质量控制方法，打破现有金属零部件增材制造技术瓶颈，最终利用该技术实现高端装备关键零部件的高效率、高品质、低成本智能化增材制造，为浙江省乃至全国制造业转型升级提供关键技术支撑

本项目针对高端装备关键部件增材制造的需求，开发了一种基于激光与冷喷涂复合的超音速激光沉积增材制造新技术。项目围绕超音速激光沉积过程中能场耦合机制、增材制造结合机理以及沉积层控形控性等方面开展基础研究。利用Johnson-Cook材料模型以数值模拟和试验相结合的方式揭示了不同材料在不同颗粒撞击速度下和激光辐照温度下的沉积行为和微观结合机制；通过对金属材料以及复合材料沉积表面形貌、成形形貌、微观组织、相组成、裂纹等进行表征，获得了激光辐照温度对材料增材沉积成形形状的调控规律；通过对复合材料中颗粒尺寸以及比例的调控，揭示了复合材料在激光辐照作用下的沉积行为；通过对沉积层耐磨、耐蚀、弯曲等性能的分析，揭示了超音速激光沉积层性能提升的机制，获得了超音速激光沉积增材制造性能调控的理论依据；在形貌、性能以及工艺研究的基础上，利用该技术实现了Cu、Al、Ti6Al4V、Inconel 718等金属材料增材制造试样的制备。项目技术已初步应用于工业汽轮机核心部件(如叶片、转子、阀杆、飞锤等)的增材改性与再制造，还可继续推广至航空航天、化工、电力、冶金等领域。