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

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.