金属增材制造技术的关键因素及发展方向

Key factors and developmental directions with regard to metal additive manufacturing

金属增材制造技术是一种短流程、近终形的新型材料成形技术.在金属增材制造技术中,设备是载体,材料是关键,工艺是基础,三者是影响金属增材制造技术发展的关键因素.本文通过对具有代表性的金属增材制造技术的特点进行总结,分析了设备、材料和工艺之间的关系以及三者在金属增材制造技术中的重要作用;综述了金属增材制造设备的原料供给系统、成形系统和控制系统的研究现状;总结了金属增材制造材料中钛合金、镍合金、铝合金和钢铁材料的典型组织特点和力学性能;论述了金属增材制造工艺参数对残余应力、孔洞、精度和组织的影响;指出了目前金属增材制造技术在设备方面存在设备成本高、产品成形尺寸受限、成形效率低等问题,在材料方面存在生产成本高、适用性差等问题,在工艺方面存在参数匹配困难、热积累严重等问题;从降低设备和材料成本、扩大产品成形尺寸范围、提高产品精度和成形效率、拓展材料种类和适用范围、减少工艺参数匹配难度、提升产品质量及综合性能、开发金属增材制造新技术方面展望了金属增材制造技术的发展方向.

Metal additive manufacturing is a new type of material-forming technology characterized by its short process and near net shape. Equipment,material and process are critical factors which serve as the supporter,key,and foundation respectively in terms of the development of this technology. In this paper,the characteristics of the equipment,material,and process of the different representative technologies were summarized. The relations among metal additive manufacturing equipment,manufacturing material,and manufacturing process as well as their roles in the metal additive manufacturing technology were analyzed. The research status of the raw material supply system,forming system,and control system were reviewed. The typical microstructure and mechanical properties of metal additive manufacturing materials,such as titanium alloy,nickel alloy,aluminum alloy,and steel,were summarized. The effects of the manufacturing process parameters on residual stress,porosity,accuracy,and microstructure were discussed. Problems associated with the manufacturing equipment,such as high cost,limited forming size,and low forming efficiency were discussed along with the problems associated with the material,such as high production cost and poor applicability. Furthermore,problems associated with the metal additive manufacturing process,such as difficult matching of process parameters and severe thermal accumulation,were elaborated as well. Future developmental goals in metal additive manufacturing include:( a) reducing the cost of manufacturing equipment and mate-rial,( b) expanding the range of product forming size,( c) improving the product printing accuracy and forming efficiency,( d) expanding the types and application scope of metal additive manufacturing material,( e) reducing the difficulty in the matching of process parameters,( f) improving product quality and comprehensive performance,and( g) developing new types of metal additive manufacturing technologies.