【摘要】 氧化物陶瓷具有优异的性能和广阔的应用前景.由于陶瓷的本征脆性,超塑性成形是陶瓷塑性加工的首选途径.但应变速率较低是制约氧化物陶瓷超塑性加工进一步应用的主要因素.本文综述了氧化物陶瓷高应变速率超塑性的最新研究进展,围绕影响超塑性变形的主要因素,如晶粒尺寸、晶粒长大、晶界扩散、化学键结构、晶界形态及空洞的形核与长大等,综述了提高超塑性应变速率的方法途径,并分析其变形行为及影响机制.更多还原

【Abstract】 Oxide ceramic is a structural material with excellent mechanical properties and wide applications. Due to its inbeing brittleness, superplastic forming provides a feasible approach to process the structural oxide ceramics. However, low strain rate is a serious limitation on superplasticity applications of the oxide ceramics in the future. This paper reviewed experimental results and superplastic models in some recent reports, and focused on the major factors limiting the deformation strain rate, such as: Grain size, dynamic grain growth, grain boundary diffusivity, chemical bonding state, grain boundary state, cavity nucleation and growth. Some existing basic and new approaches to achieving high strain rate superplasticity in oxide ceramics were summarized. The superplastic behaviors and enhancement mechanisms were also discussed.更多还原