The turbine inlet temperature (TIT) of an engine is a critical factor affecting the thrust-to-weight ratio. With the upgrade and replacement of fighter jets, the TIT increases significantly. Therefore, there is an urgent need to develop advanced structural materials that can maintain excellent mechanical properties and corrosion resistance in ultra-high temperature extreme environments, and explore efficient and controllable preparation processes to meet the service requirements of future engines. Among numerous materials, oxide composite ceramics possess outstanding high-temperature corrosion resistance and oxidation resistance, and exhibit excellent high-temperature mechanical properties and remarkable microstructural stability. They become one of the most promising candidates for ultra-high temperature structural materials. So far, oxide composite ceramics have been successfully prepared through a variety of technologies. However, these solidification technologies have obvious limitations in preparing large-sized complex-shaped or hollow components.

The emergence of laser additive manufacturing (LAM) technology provides a possibility to solve these problems. The application of LAM technology in the preparation of oxide composite ceramics is expected to break through the bottleneck in the preparation of large-sized complex components. However, compared with metal materials, ceramic materials have characteristics such as high melting point, high brittleness, and high melt viscosity, which easily lead to defects like cracks and pores during the LAM process, greatly restricting their engineering application. The molten pool, as the basic unit in the LAM forming process, directly affects the forming quality, microstructure, and mechanical properties of the obtained samples through its internal flow state, grain growth mechanism, and the distribution and evolution of the temperature and stress fields.

This review first compares the working principles and process characteristics of two mainstream LAM technologies for preparing oxide composite ceramics, and analyzes the temperature distribution laws and flow characteristics of the molten pool in LAM ultra-high temperature oxide ceramics. Subsequently, it systematically summarizes the research progress on visual and temperature monitoring technologies in the molten pool monitoring of LAM oxide ceramics, and discusses the improvement of the molten pool through process parameter regulation and doping, as well as the application progress of numerical simulation in this field. Finally, the future development and directions of LAM ultra-high temperature oxide eutectic ceramics are prospected.

The main research results obtained are as follows: 1) The processes of preparing oxide composite ceramics by two technologies, i.e., laser directed energy deposition (LDED) and laser powder bed fusion (LPBF), are compared. The differences between the two processes in key parameters such as powder delivery, spot size, and scanning speed are clarified, and the preparation of oxide composite ceramic components with wall-like, angular, and irregular complex shapes is realized; 2) The temperature distribution and flow characteristics of the molten pool of oxide composite ceramics during the LAM process are deeply revealed. The molten pool temperature characteristics and the resulting residual stress and crack formation mechanism are clarified. The influence of the molten pool flow mode dominated by the Marangoni convection on the pore formation and the microstructure evolution law caused by differences in undercooling is also analyzed; and 3) A numerical simulation technology for the molten pool of LAM oxide composite ceramics is established, the heat source model is optimized, and the influence of process parameters on the molten pool behavior is clarified. The microstructure evolution and defect formation mechanism of oxide composite ceramics are revealed through multi-field coupling, providing a theoretical support for defect suppression.