【摘要】 利用透射电镜对莫来石陶瓷中位错的组态进行观察,结果表明,莫来石陶瓷中的位错易被第二相钉扎,两列位错相遇易发生反应,全位错易分解成偏位错,并扩展形成层错。这说明,即使是脆性材料,其位错在一定条件下仍然是可动的。本文认为,位错在常温和高温条件下对莫来石陶瓷力学性能影响不同,并从位错的角度解释了莫来石陶瓷力学性能的特点,提出改进材料制备工艺的途径。更多还原

【Abstract】 The behaviors of dislocation in Mullite ceramics have been investigated by Transmission Electron Microscope. The experimental results show that the dislocations can be pinned by the second phase such as glassy phase and t-ZrO2 particles. Two dislocation arrays of different direction can react each other and result in the formation of stacking faults. This phenomenon indicates that the dislocations are mobile at certain condition even in brittle materials. It is assumed that the effects of dislocation on the mechanical properties are different at room and high temperatures. The effects of dislocation on the mechanical properties have been discussed and the measures for optimizing the material preparation have been proposed.更多还原