Influence of the Y2O3 content and temperature on the mechanical properties of melt-grown Al2O3-ZrO2 eutectics
Influence of the Y2O3 content and temperature on the mechanical properties of melt-grown Al2O3-ZrO2 eutectics
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DOI：
10.1111/j.1551-2916.2004.00633.x
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发表时间：
2004-04-01
影响因子：
3.9
通讯作者：
Orera, VM
中科院分区：
文献类型：
--
作者：
LLorca, J;Pastor, JY;Orera, VM
在25 ℃ ~ 1427 ℃温度范围内研究了Y_2O_3含量对熔体生长Al_2O_3-ZrO_2共晶抗弯强度的影响。仔细控制处理条件以获得独立于Y2 O3含量的恒定显微结构。棒的微观结构是由交替带的细和粗分散的不规则的ZrO 2片晶取向沿着生长轴和嵌入在连续的Al 2 O 3基质。最高的弯曲强度在环境温度下被发现在材料与3摩尔%的Y2 O3相对于ZrO 2（Y2 O3）。较高的Y2 O3含量没有实质性地修改的机械响应，然而，材料与0.5摩尔%的弯曲强度呈现出显着的退化，因为存在大的缺陷。它们在冷却时ZrO 2的马氏体相变过程中在Al 2 O3-ZrO 2界面处形核，并在相变产生的拉伸残余应力的驱动下传播到Al 2 O3基体中。与3摩尔%的Y2 O3的材料保留80%的抗弯强度在1427 degreesC，而与0.5摩尔%的Y2 O3的共晶的机械性能随温度迅速下降，作为广泛的微裂纹的结果。
The effect of Y2O3 content on the flexure strength of melt-grown Al2O3-ZrO2 eutectics was studied in a temperature range of 25degrees-1427degreesC. The processing conditions were carefully controlled to obtain a constant microstructure independent of Y2O3 content. The rod microstructure was made up of alternating bands of fine and coarse dispersions of irregular ZrO2 platelets oriented along the growth axis and embedded in the continuous Al2O3 matrix. The highest flexure strength at ambient temperature was found in the material with 3 mol% Y2O3 in relation to ZrO2(Y2O3). Higher Y2O3 content did not substantially modify the mechanical response; however, materials with 0.5 mol% presented a significant degradation in the flexure strength because of the presence of large defects. They were nucleated at the Al2O3-ZrO2 interface during the martensitic transformation of ZrO2 on cooling and propagated into the Al2O3 matrix driven by the tensile residual stresses generated by the transformation. The material with 3 mol% Y2O3 retained 80% of the flexure strength at 1427degreesC, whereas the mechanical properties of the eutectic with 0.5 mol% Y2O3 dropped rapidly with temperature as a result of extensive microcracking.