Abstract—

Liquid-assisted processes that occur in iridium–silicon carbide diffusion couples have been studied in the temperature range 1500–1800°C at different heat treatment times. We have examined the microstructure and determined the elemental and phase compositions of the diffusion zone forming above eutectic temperatures and/or the melting points of individual reaction products: iridium silicides. The microstructure of the diffusion zone forming under liquid formation conditions has been shown to differ from that forming under the conditions of solid-state reaction between iridium and silicon carbide. At temperatures above 1700°C, the silicon content of the Ir–Si melt exceeds 50 mol %, which leads to crystallization of the Ir₃Si₄ and Ir₃Si₅ phases during cooling. The carbon resulting from reaction between iridium and SiC undergoes graphitization with increasing heat treatment temperature and time.

中文翻译：

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铱与碳化硅陶瓷的液体辅助相互作用

摘要-

在 1500-1800°C 的温度范围内，在不同的热处理时间下，研究了铱-碳化硅扩散偶中发生的液体辅助过程。我们检查了微观结构，并确定了在共晶温度和/或单个反应产物（硅化铱）熔点以上形成的扩散区的元素和相组成。已经表明，在液态形成条件下形成的扩散区的微观结构与在铱和碳化硅之间的固态反应条件下形成的扩散区的微观结构不同。在1700°C以上的温度下，Ir-Si熔体的硅含量超过50 mol%，这导致Ir ₃ Si ₄和Ir ₃ Si ₅相在冷却过程中结晶。随着热处理温度和时间的增加，铱和碳化硅之间反应产生的碳会发生石墨化。