熔体自生陶瓷激光直接能量沉积增材制造研究进展

Research progress in additive manufacturing of melt growth ceramics by laser directed energy deposition

熔体自生陶瓷是一种原料经熔化凝固获得组织组成的新型陶瓷材料,原子共用的洁净高强度结合界面使其具有接近熔点的优异高温力学性能及组织稳定性,在未来高推重比航空发动机及重型燃气轮机热端部件领域展现了巨大的应用潜力。激光直接能量沉积技术能够有效克服熔体自生陶瓷传统制备方法在周期、能耗及结构复杂度等方面的局限,为直接增材制造熔体自生陶瓷构件提供了新的解决方案,成为国内外研究热点。本文在介绍激光直接能量沉积技术工艺原理的基础上,总结了国内外利用该技术制备的不同熔体自生陶瓷的微观组织特征及其主要力学性能,并综合论述了目前针对微观组织及开裂行为调控所开展的主要研究。基于现有研究进展,对该领域的发展趋势和需要进一步解决的关键科学问题进行了探讨,指出抑制开裂与改善组织性能是目前面临的首要问题,材料和新工艺的发展是突破现有瓶颈、推动熔体自生陶瓷激光直接能量沉积技术发展和应用的关键。

Melt growth ceramics(MGC)is a new type of ceramic material with microstructure obtained by melting and solidification of raw materials.The clean and high-strength bonding interface shared by atoms makes it have excellent high-temperature mechanical properties and microstructure stability close to the melting point.It shows great application potential in the field of high thrust weight ratio aero-engine and heavy gas turbine hot end components in the future.Laser directed energy deposition(LDED)technology can effectively overcome the limitations of traditional preparation methods of MGC in terms of cycle,energy consumption and structural complexity.It provides a new solution for direct additive manufacturing of MGC components,and has become a research hotspot at home and abroad.Based on the introduction of the process principle of LDED technology,the microstructure characteristics and properties of different MGCs prepared by this technology at home and abroad were summarized in this paper,and the main research on the control of microstructure and cracking behaviour was comprehensively discussed.Based on the existing research progress,the development trend and key scientific problems to be further solved in this field were discussed.It was pointed out that inhibiting cracking and improving microstructure and properties are the primary problems faced at present.The development of materials and new processes is the key to breaking through the existing bottleneck and promote the development and application of MGC-LDED.