熔融生长的Al₂O₃-ZrO₂共晶陶瓷具有优异的高温性能。采用激光粉末床熔融（LPBF）直接制备Al₂O₃-ZrO₂共晶陶瓷，研究了不同激光功率下的单道形貌特征及块体表面质量、物相组成、微观组织结构的演变规律和力学性能。结果表明，激光功率的提升将增加熔池的长度和单沉积道的宽度。Al₂O₃-ZrO₂共晶陶瓷的表面粗糙度（R_a）和气孔率均随着激光功率的增加先降低后升高。在没有添加Y₂O₃等稳定剂的条件下，Al₂O₃-ZrO₂共晶陶瓷的物相主要包括α-Al₂O₃、m-ZrO₂和亚稳相t-ZrO₂。随着激光功率的增加，m-ZrO₂逐渐减少，这是由于LPBF的快速冷却过程抑制了马氏体相变。样件的晶粒尺寸随着激光功率的增加呈增大趋势，晶界密度减小，因此测量的显微硬度和断裂韧性呈现下降的趋势。当激光功率为60 W时，得到硬度为H_v=17.19 GPa和断裂韧性为K_IC=6.67 MPa·m^1/2的最优力学性能样品。

The solid solutions of the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system were produced by the conventional ceramic technology using mechanical activation of the synthesized product. It was found that in the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system at room temperature, a number of morphotropic phase transitions occur: rhombohedral → cubic → tetragonal → monoclinic phases. The introduction of a small amount of Na0.5K0.5NbO₃ leads to an increase in the temperature stability of the dielectric properties of ceramics. A change in the relaxor properties of the solid solutions of the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system was shown. The increase in energy density and energy efficiency was found at additive 10mol.% of Na0.5K0.5NbO₃.

Ferroelectric ceramics have the potential to be widely applied in the modern industry and military power systems due to their ultrafast charging/discharging speed and high energy density. Considering the structural design and electrical properties of ferroelectric capacitor, it is still a challenge to find out the optimal energy storage of ferroelectric ceramics during the phase-transition process of amorphous/nanocrystalline and polycrystalline. In this work, a finite element model suitable for the multiphase ceramic system is constructed based on the phase field breakdown theory. The nonlinear coupling relationship of multiple physical fields between multiphase ceramics was taken into account in this model. The basic structures of multiphase ceramics are generated by using the Voronoi diagram construction method. The specified structure of multiphase ceramics in the phase-transition process of amorphous/nanocrystalline and polycrystalline was further obtained through the grain boundary diffusion equation. The simulation results show that the multiphase ceramics have an optimal energy storage in the process of amorphous polycrystalline transformation, and the energy storage density reaches the maximum when the crystallinity is 13.96% and the volume fraction of grain is 2.08%. It provides a research plan and idea for revealing the correlation between microstructure and breakdown characteristics of multiphase ceramics. This simulation model realizes the nonlinear coupling of the multiphase ceramic mesoscopic structure and the phase field breakdown. It provides a reference scheme for the structural design and performance optimization of ferroelectric ceramics.

新型高温热障涂层材料已成为新一代航空发动机发展的关键材料。本工作通过固相反应法合成了一种单斜结构的高熵稀土钽酸盐材料(Y0.2Gd0.2Dy0.2Ce0.2La0.2)TaO4[(5RE0.2)TaO4]，研究了其热、力学性能及抗熔融硅酸盐环境沉积物(CMAS)侵蚀性能。结果表明：(5RE0.2)TaO4具有极低的热导率(1.22 W·m-1·K-1，600 ℃)和较高的热膨胀系数(10.3×10-6 K-1，1 200 ℃)，与YSZ材料相比(2.1～2.7 W·m-1·K-1，100～900 ℃)热导率下降了近42%。由于独特的铁弹增韧效应，其断裂韧性达2.8 MPa·m1/2，优于多数新型热障涂层材料。1 350 ℃不同时间及CMAS侵蚀后，(5RE0.2)TaO4反应层厚度和渗透深度均显著小于YSZ材料，是一种极具应用潜力的新型热障涂层材料。