Effect of Integral High-Temperature Assist on Microstructure and Mechanical Properties of Al2O3/ZrO2 Eutectic Ceramics Prepared by Laser Directed Energy Deposition
YU Xuexin1, 2, LI Chengxin3, MENG Chaoxin1, 2, GAO Jiali2, 4, MA Guangyi1, 2, WU Dongjiang1, 2, NIU Fangyong1, 2
1. State Key Laboratory of High-Performance Precision Manufacturing, Dalian University of Technology, Dalian 116024, China;
2. Key Laboratory for Precision /Non-Traditional Machining Technology and Microfabrication Technology of Ministry of Education (B), Dalian 116024, China;
3. Xi’an Aerospace Power Machinery Co., Ltd., Xi’an 710025, China;
4. University of Shanghai for Science and Technology, Shanghai 200093, China
Al2O3/ZrO2 eutectic ceramics, with excellent high-temperature mechanical properties and structural stability, ave become potential materials for hot-end components in aero-engines and gas turbines. Laser directed energy deposition (LDED) technology overcomes the limitations of traditional fabrication methods, such as sintering deformation, by directly melting powders to enable the one-step fabrication of complex ceramic components. The application of integral hightemperature assistance can effectively suppress cracking during the fabricating process. However, the effect of high-temperature assistance on the microstructure and properties of the fabricated components remains unclear. This work systematically investigates the evolution of the microstructure and mechanical properties of Al2O3/ZrO2 eutectic ceramics fabricated by LDED with integral high-temperature assistance as a function of the assistance temperature. The results show that the integral hightemperature assistance significantly influences the microstructure and mechanical properties of Al2O3/ZrO2 eutectic ceramics. At an assistance temperature of 1273 K, the grain size of the fabricated sample increases by approximately 32.16% compared to samples manufactured at room temperature. The average fracture toughness is (4.9±0.3) MPa·m1/2, which represents a 17.2% improvement over room-temperature samples. The flexural strength and compressive strength reach their maximum at an assistance temperature of 773 K, with values of (324.27±18.23) MPa and (354.19±37.53) MPa, respectively.