通过反应性和非反应性火花等离子烧结的高二氧化物-碳化复合材料:一项比较研究
Ekaterina Pakhomova1, Giacomo Cao1, Roberto Orrù1
1Unità di Ricerca del Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, 09123 Cagliari, Italy.
Materials (Basel, Switzerland)
|April 9, 2024
概括
两步自扩散的高温合成火花等离子烧结 (SHS-SPS) 路径优于反应火花等离子烧结 (R-SPS) 路径,用于制造密集的超高温陶. 这种方法为先进的材料应用提供了改进的微观结构和增强的特性.
科学领域:
- 材料科学 材料科学 材料科学
- 陶工程 陶工程
- 高温合成 高温合成
背景情况:
- 开发密集和均的超高温陶 (UHTC) 对极端环境应用至关重要.
- 传统的反应性火花等离子烧结 (R-SPS) 可以导致多相和不均的产品.
- 需要使用替代的制造途径来克服R-SPS对UHTC的局限性.
研究的目的:
- 为了比较反应性火花等离子烧结 (R-SPS) 的有效性与两步自传播的高温合成火花等离子烧结 (SHS-SPS) 路径.
- 为了制造密集的 (Hf0.2Mo0.2Ti0.2Ta0.2Nb0.2) B2-SiC和 (Hf0.2Mo0.2Ti0.2Ta0.2Zr0.2) B2-SiC的陶.
- 评估通过这两种方法生产的陶的微观结构,密度和机械性能.
主要方法:
- 使用反应性火花等离子烧结 (R-SPS) 在2000°C20分钟制造UHTC.
- 两步制造涉及自我传播的高温合成 (SHS),然后在最佳条件下 (1800°C20分钟) 进行火花等离子烧结 (SPS).
- 相对密度,微观结构,残留氧化物含量和断裂性的表征.
主要成果:
- R-SPS从过渡金属,B4C和Si.产生了多相和不均的产品.
- 在SHS-SPS路线成功地生产了密集的陶 (>97%的相对密度) 与均的微观结构 (<2.4%的残留氧化物).
- 加入SiC降低了150°C的烧结温度,提高了断裂性,同时也抑制了氧化物挥发.
结论:
- 与R-SPS相比,两步SHS-SPS路线是制造密集的UHTC的更有效的方法.
- 通过SHS-SPS方法,可以实现优越的微观结构统一性和增强的机械性能,包括断裂性.
- 在SHS-SPS中复合成分的并行合成促进了强大的接口,有助于提高材料性能.
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