EFFECT OF GRAIN SIZE ON THE MARTENSITIC TRANSFORMATION AND NUCLEATION MECHANISM IN CERIA-DOPED TETRAGONAL ZIRCONIA POLYCRYSTALS

晶粒尺寸对二氧化铈四方氧化锆多晶马氏体相变及成核机制的影响

• 批准号: 03650528
• 负责人: HAYAKAWA Motozo
• 金额: $ 1.34万
• 依托单位: TOTTORI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650528/
• 关键词: Partially Stabilized Zirconia; Tetragonal Zirconia Polycrystals; Martensitic Transformation; Grain Size; Hardness; Powder Specimen; Isothermal Transformation; Grain Growth; 粒末試料; セリア-正方晶ジルコニア多結晶体; 結晶粒径依存; 曲げ強度; 変態温度

Effect of grain size/particle size was studied on the martensitic transformation temperature(Ms) using both bulk and pulverized specimens of ceria-doped TZP(tetragonal Zirconia Polycrystals). In bulk specimens, the Ms markedly decreased with grain refinement with concurrent hardening of the matrix. In powder specimens, the Ms varied only moderately with the particles size independently of the grain size. The Ms of the bulk specimen was lower than that of powders of the same grain size.From these results, it was suggested that the constraining stress in a bulk specimen was an essential factor for the grain size dependence of Ms. Although the exact nature of the constraining stress could not be known, the increase of the average yield stress resulting from the grain refinement was conjectured. This would naturally suppress the nucleation of martensite since the large transformation strain associated with the nucleation must be elastically and plastically accommodated by the surrounding matrix. This model successfully explains the present experimental observations. On the other hand, the existing theory in which stress concentration at the grain boundary owing to the anisotropic thermal expansion coefficient would fail to account for the lower Ms for a bulk than powders.

使用二氧化铈掺杂 TZP（四方氧化锆多晶）的块状和粉碎样品研究了晶粒尺寸/颗粒尺寸对马氏体转变温度（Ms）的影响。在大块样品中，随着晶粒细化和基体同时硬化，Ms 显着降低。在粉末样品中，Ms 仅随颗粒尺寸适度变化，与晶粒尺寸无关。大块样品的 Ms 低于相同晶粒尺寸的粉末。从这些结果可以看出，大块样品中的约束应力是影响 Ms 晶粒尺寸依赖性的重要因素。由于约束应力无法得知，推测晶粒细化导致平均屈服应力增加。这自然会抑制马氏体的成核，因为与成核相关的大转变应变必须由周围的基体弹性和塑性地适应。该模型成功地解释了目前的实验观察结果。另一方面，现有的理论认为，由于各向异性热膨胀系数而导致晶界处的应力集中，无法解释块体比粉末的更低的Ms。

项目成果

早川 元造: "Effect of Grain Size on the Martensitic Transformation in CeO_2-Tetragonarl Zirconia Polycrystals" 鳥取大学工学部研究報告. 22. 1-14 (1991)

早川元三：“晶粒尺寸对 CeO_2-四方氧化锆多晶中马氏体转变的影响”鸟取大学工学部研究报告 22. 1-14 (1991)。

早川 元造: "Effect of Grain Size on the Martensitic Transformation in CeO_2-TZP" Proc.International Conference on Martensitic Transformation,92. (1993)

Motozo Hayakawa：“晶粒尺寸对 CeO_2-TZP 中马氏体转变的影响”Proc.国际马氏体转变会议，92（1993）。

早川 元造: "Effect of Grain Siqe on the Martensitic Transfornation in Ceo_2-Teragonal Zirconia Polycrystals" 鳥取大学工学部研究報告. 22. 1-14 (1991)

早川元三：“晶粒 Siqe 对 Ceo_2-四方氧化锆多晶中马氏体相变的影响”鸟取大学工学部研究报告 22. 1-14 (1991)。

早川 元造: "Effect of Grain Size on the Martensitic Transformation in CeO_2ーTetragonal Zirconia Polycrystals" 鳥取大学工学部研究報告. 22. 1-14 (1991)

早川元三：“晶粒尺寸对 CeO_2-四方氧化锆多晶中马氏体转变的影响”鸟取大学工学部研究报告 22. 1-14 (1991)。

M.Hayakawa, H.Sinmen, and M.Oka: "Effect of Grain Size on the Martensitic Transformation in CeO_2-TZP" Proc. ICOMAT-92. (1993)

M.Hayakawa、H.Sinmen 和 M.Oka：“晶粒尺寸对 CeO_2-TZP 中马氏体转变的影响”Proc。