增材制造技术发展和在先进轨道交通装备中的应用展望

从增材制造技术的应用现状出发，概述了几种增材制造技术的特点和应用范围；介绍了典型的金属增材制造最新研究进展；考虑现有增材制件存在的固有缺陷、残余应力和裂纹等问题，总结了能有效改善成形增材制件质量的后处理工序；梳理了增材制件疲劳性能的影响因素，重点阐述了缺陷与增材制件疲劳损伤的关联性；探讨了增材制造技术广泛应用所涉及的关键技术；系统总结了金属增材制造技术在国内外轨道交通装备领域的应用现状。研究结果表明:由于热源和工艺参数不同，增材制造技术制备材料的组织特性和力学性能存在差异；增材制造的钛合金、铝合金以及其他前沿金属材料在轨道交通装备领域具有较好的应用前景；合理的后处理工艺可以有效控制缺陷的形成，消除残余应力，减少微裂纹；缺陷作为制约增材制造技术在制造行业应用的关键因素，研究其分布规律和探究其与疲劳性能的关系，对增材制件的疲劳性能评估有重要作用；从材料规范、成形精度、质量控制、生产效率、生产链以及无损检测技术等方面，综合增强增材制造关键技术自主创新性研发，有助于提升中国制造行业在国际上的竞争力；增材制造技术受到轨道交通行业的重视，并开始应用这种新型技术成形了金属结构件，但该技术的成熟应用仍面临许多问题，需要国内外学者进一步开展深入研究。 

Development of additive manufacturing technology and its application prospect in advanced rail transit equipment

Based on the application status of additive manufacturing technology, the characteristics and application ranges of several additive manufacturing technologies were summarized. The latest research progress of typical metal additive manufacturing was introduced. Considering the inherent defects, residual stresses and cracks of the existing additive manufactured parts, the post processes which can effectively improve the quality of the formed additive manufactured parts were summarized. The influencing factors of fatigue performance of additive manufactured parts were sorted out, and the correlation between defect and fatigue damage of additive manufactured parts was emphasized. The key technologies involved in the wide application of additive manufacturing technology were discussed. The application status of metal additive manufacturing technology in the field of rail transit equipment at home and abroad was systematically summarized. Analysis result shows that the texture characteristic and mechanical properties of materials prepared by the additive manufacturing technology are different due to different heat sources and process parameters. Additive manufacturing titanium alloy, aluminum alloy and other advanced metal materials have a good application prospect in the field of rail transit equipment. Reasonable post processes can effectively control the formation of defects, eliminate residual stresses and reduce micro cracks. Defects are the key factors to restrict the application of additive manufacturing technology in the manufacturing industry, it is important to study the distribution law of defects and explore the relationship between defects and fatigue performance for the evaluation of fatigue performance of additive manufactured parts. From the aspects of material specification, forming accuracy, quality control, production efficiency, production chain and nondestructive testing technology, comprehensively improving the independent and innovative research and development of key technologies of additive manufacturing is conducive to enhancing the competitiveness of Chinese manufacturing industry in the world. The additive manufacturing technology has attracted the attention of rail transit industry, and begin to adopt this new technology to form metal structural parts, but the wide application of this technology still faces many problems, which need to carry out in-depth research by the scholars at home and abroad. 2 tabs, 21 figs, 111 refs.