@article{TENG2026, 
author = {Jiachen TENG and Qiaolei LI and Liang XIAO and Xinyan YUE and Yuxiang QIU and Xuan ZHOU and Fulin ZHU and Tao XU and Xiaofeng ZENG and Jingjing LIANG and Yizhou ZHOU and Jinguo LI},
title = {Effect of extreme service temperatures on microstructure and strength of additively manufactured silicon nitride},
year = {2026},
journal = {Journal of Aeronautical Materials},
volume = {46},
number = {1},
pages = {109-120},
keywords = {additive manufacturing, silicon nitride, extreme service temperature, microstructure, flexural strength},
url = {https://www.sciopen.com/article/10.11868/j.issn.1005-5053.2025.000135},
doi = {10.11868/j.issn.1005-5053.2025.000135},
abstract = {Additive manufacturing technology provides a novel approach for the production of complex-structured silicon nitride ceramics. In this study, the microstructural and strength evolution of additively manufactured silicon nitride after continuous thermal exposure for 24 hours in an oxygen-containing atmosphere at 1200-1500 ℃ are investigated. The morphology, phase compositions and element distribution are characterized by SEM, XRD, EBSD and EPMA. The results show that with increasing exposure temperature, α→β phase transformation occurs, and the volume fraction of β-Si3N4 increases from 63.02% to 74.15%. Meanwhile, the grain size of silicon nitride grows from 1.33 μm at 1200 ℃ to 1.97 μm at 1500 ℃. The flexural strength exhibits a rise-then-fall trend with increasing temperature, reaching a peak value of 722.67 MPa at 1200 ℃ and dropping to a minimum of 242.67 MPa at 1500 ℃, which represents a reduction of approximately 66.00% compared to the unexposed condition. Grain coarsening, as well as the formation of pores and microcracks during thermal exposure, are the primary causes of strength degradation. In addition, high-temperature oxidation reactions lead to the formation of mechanically weak SiO2 phases and introduce dimensional inaccuracies, further compromising the mechanical performance of the additively manufactured silicon nitride. As a result, flexural strength continues to decrease with increasing exposure temperature. This study reveals the microstructural and mechanical evolution mechanisms of additively manufactured silicon nitride ceramics under extreme high-temperature service conditions, providing a theoretical foundation for improving their service reliability and process optimization.}
}