Continuous silicon nitride (Si₃N₄) fibers are considered as one of the most promising high-temperature wave-transparent fibers, the high-temperature performance of which need to be investigated. The Si₃N₄ fibers were heat-treated at elevated temperatures for different duration times in air and N₂ atmosphere, respectively. The compositions, microstructures and mechanical properties were investigated by XRD, XPS, SEM and tensile strength analysis. The results show that the heat-treatment temperature, exposure time and atmosphere all have effects on the performance of the fibers. And the decrease in strength of the Si₃N₄ fibers annealed in N₂ is due to the thermal decomposition of Si_xN_yO and grain growth of Si₃N₄, while the degradation of the fibers annealed in air is mainly owing to the oxidation reactions.

连续的氮化硅（Si ₃ N ₄）纤维被认为是最有希望的高温波透明纤维之一，其高温性能需要研究。将Si ₃ N ₄纤维分别在空气和N ₂气氛中在升高的温度下热处理不同的持续时间。通过XRD，XPS，SEM和拉伸强度分析研究了组成，微观结构和力学性能。结果表明，热处理温度，暴露时间和气氛都对纤维的性能有影响。N _2中退火的Si ₃ N ₄纤维的强度下降这是由于Si _x N _y O的热分解和Si ₃ N _4的晶粒长大，而在空气中退火的纤维的降解主要是由于氧化反应。