摘要
本文讨论t-ZrO_2/β″-A1_2O_3陶瓷中晶界ZrO_2粒子的长大机制和c-ZrO_2/β″-A1_2O_3、t-ZrO_2/β″-A1_2O_3陶瓷中ZrO_2的韧化机制。“直接合并”是ZrO_2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-ZrO_2/β″-A1_2O_3和t-ZrO_2/β″-Al_2O_3陶瓷中,强度的提高是由于断裂韧性提高的结果。c-ZrO_2的韧化机制是弥散韧化。应力诱发相变韧化是t-ZrO_2的主要韧化机制,弥散韧化对t-ZrO_2/β″-A1_2O_3的断裂韧性的提高也起作用。
This paper discusses the particle growth mechanism of intergranular ZrO_2 particles of t-ZrO_2/β″-Al_2O_3 and the toughening mechanism of ZrO_2 of c-ZrO_2/β″-Al_2O_3 composites and of t-ZrO_2/β″-Al_2O_3 composites.Direct particle coalescence was identified as magor growth mechanism but ostwald ripering was also observed to contribute. The coalescence of ZrO_2 particles progressed via encounter and spheroidization processes. The increase of fracture toughness leads to an increased strength of c-ZrO_2/β″-Al_2O_3 and t-ZrO_2/β″-Al_2O_3. Dispersion toughening is the toughening mechanism of c-ZrO_2.Stress-induced transformation toughening is the predominant toughening mechanism of t-ZrO_2. Dispersion toughening also contributes to the increase of fracture toughness of the t-ZrO/β″-Al_2O_3.
出处
《粉末冶金技术》
CAS
CSCD
北大核心
1990年第2期66-74,共9页
Powder Metallurgy Technology
