摘要
在１３５０～１５５０℃下，对３ｍｏｌ％Ｙ２Ｏ３稳定的四方ＺｒＯ２多晶陶瓷（Ｙ－ＴＺＰ）进行了超塑性拉伸试验，最大延伸率达２８５％。研究了拉伸变形特性，测定了１４６０℃下的应变速率敏感性指数ｍ＝０．３７。扫描电镜、透射电镜和Ｘ射线衍射仪研究表明；Ｙ元素在晶界处偏析；超塑变形时晶粒明显长大；变形促进了四方相（ｔ）→单斜相（ｍ）ＺｒＯ２的马氏体转变，其相位关系为（１００）ｍ∥（１００）ｔ；，［００１］ｍ∥［００１］ｔ，αｍ＾αｔ＝９．３°，ｍ－ＺｒＯ２呈板条状。Ｘ射线光电子谱（ＸＰＳ）结果说明：晶界玻璃相不是陶瓷超塑性变形的先决条件。
The tensile characteristics and microstructure of superplastic Y-TZP ceramics have been investigated at 1 350～1 550℃. Under optimum conditions, an elongation of 285 % has been obtained. The strain rate sensitivity, m = 0. 37 at 1 450 ℃ and with an initial strain rate of 10(-3)～10(-5) s(-1). Microstructure examination did not reveal the presence of a glassy phase at grain boundaries. However,yttrium was found to segregate to the grain boundaries.The microstructure of Y-TZP was thermally unstable and appreciable grain growth was observed during tensile deformation. The tetragonal to monoclinic zirconia martensite transformation was enhanced by tensile defomation.The phase orientation relationship between m-ZrO2 and tZrO2 matrix was found to be (100)m
出处
《南京航空航天大学学报》
CAS
CSCD
1996年第2期187-192,共6页
Journal of Nanjing University of Aeronautics & Astronautics
基金
国家"863"计划和教委博士点专项基金
