摘要
以不同Y2O3含量及晶粒大小的Y-TZP陶瓷为研究对象,揭示了掺杂剂含量及晶粒尺寸对Y-TZP陶瓷在低温下的相变过程及力学性能的影响规律。研究发现3Y-TZP陶瓷及晶粒大小为156nm的2Y-TZP陶瓷在温度从室温降低到77K的过程中,断裂韧性单调升高;而晶粒大小为595nm的2Y-TZP陶瓷在195K附近断裂韧性达到最大值10.34MPa·m1/2,随着温度继续降低至77K,其断裂韧性明显劣化。通过低温在线Raman测试,表明2Y-TZP(595nm)的马氏体相变开始温度(Ms温度)约为195K,在这一温度附近材料断裂韧性达到最大值,当温度低于Ms温度时,自发马氏体相变的发生导致材料性能的劣化。本研究表明可以通过控制掺杂剂含量和晶粒尺寸使其获得最优的低温断裂韧性。
The effect of Y2O3 contents and grain sizes on the tetragonal to monoclinic transformation and mechanical properties of Y-TZP ceramics with different Y2O3 contents and grain sizes at cryogenic temperatures has been investigated. Results show that the fracture toughness of 3Y-TZP and 2Y-TZP (grain size=156 nm) ceramics monotonously increases with decreasing temperature from 293 K to 77 K. During cooling, fracture toughness of 2Y-TZP (grain size=156 nm) ceramics firstly reaches the maximum of 10.34 MPa·m 1/2 at about 195 K and then decreases with decreasing temperatures to 77 K. This degradation of fracture toughness is attributed to the occurrence of spontaneous tetragonal to monoclinic transformation cooling from 195 K, which is demonstrated by in-situ Raman spectroscopy. Therefore, the optimum fracture toughness at cryogenic temperatures can be obtained by adjusting the doping contents and grain size.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2013年第S1期256-259,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51232004)
关键词
氧化锆陶瓷
力学性能
低温
相变
zirconia
mechanical properties
cryogenic temperatures
transformation
