ZrO2增韧β″-Al2O3陶瓷中ZrO2的长大机制和韧化机制

殷声

ZrO₂增韧β″-Al₂O₃陶瓷中ZrO₂的长大机制和韧化机制

殷声

北京科技大学

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ZrO₂ PARTICLE GROWTH MECHANISM AND TOUGHENING MECHANISM OF ZrO₂/β″-Al₂O₃

Yin Sheng

University of Science and Technology Beijing

摘要

摘要: 本文讨论t-ZrO₂/β″-Al₂O₃陶瓷中晶界ZrO₂粒子的长大机制和c-ZrO₂/β″-Al₂O₃、t-ZrO₂/β″-Al₂O₃陶瓷中ZrO₂的韧化机制。“直接合并”是ZrO₂粒子长大的主要机制,Ostwald粗化机制也起作用。粒子的合并包括“相遇”和球化两个过程。在c-ZrO₂/β″-Al₂O₃和t-ZrO₂/β″-Al₂O₃陶瓷中,强度的提高是由于断裂韧性提高的结果。c-ZrO₂的韧化机制是弥散韧化。应力诱发相变韧化是t-ZrO₂的主要韧化机制,弥散韧化对t-ZrO₂/β″-Al₂O₃的断裂韧性的提高也起作用。
- ZrO₂ /
- 相变增韧 /
- β"-Al₂O₃ /
- 弥散韧化 /
- 直接合并 /
- ostwald粗化
Abstract: This paper discusses the particle growth mechanism of intergranular ZrO₂ particles of t-ZrO₂/β″-Al₂O₃ and the toughening mechanism of ZrO₂ of c-ZrO₂/β″-Al₂O₃ composites and of t-ZrO₂/β″-Al₂O₃ composites.Direct particle coalescence was identified as magor growth mechanism but ostwald ripering was also observed to contribute. The coalescence of ZrO₂ particles progressed via encounter and spheroidization processes. The increase of fracture toughness leads to an increased strength of c-ZrO₂/β″-Al₂O₃ and t-ZrO₂/β″-Al₂O₃. Dispersion toughening is the toughening mechanism of c-ZrO₂.
Stress-induced transformation toughening is the predominant toughening mechanism of t-ZrO₂. Dispersion toughening also contributes to the increase of fracture toughness of the t-ZrO/β″-Al₂O₃.