BRITTLENESS,TOUGHNESS AND DUCTILITY OF CERAMICS -THE MICROSCOPIC PROCESSES AND CHARACTERIZATION.

陶瓷的脆性、韧性和延展性 - 微观过程和表征。

• 批准号: 07555194
• 负责人: SAKAI Mototsugu
• 金额: $ 8万
• 依托单位: TOYOHASHI UNIVERSITY OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555194/
• 关键词: CERAMICS; BRITTLENESS; TOUGHNESS; DOUCTILIGY; CHARACTERIZATION,ANALYSIS; 靱性; 圧子力学; 高温変形; クリープ; 応力緩和

1) The brittleness and the ductility as characteristic material parameters were defind and derived based on an energry principle of indentation contact mechanics. The brittleness/ductility parameter gives a quantitative measure for characterizing the machinability of brittle materials.2) An apparatus was designed for characterizing the brittleness/ductility parameter and the degree of indentation-induced damage in a wide range of temperatures ranging from room temperature to 1,400ﾟC.3) Conducted were the theoretical consideration and experimental work of viscoelatic indentation contact deformation of brittle materials at elevated temperatures. The indentation hysteresis energy was successfully utilized to characterize the viscoelastic behavior of surface deformation.4) An acoustic microscopy was applied to the surface damage introduced by indentation contact. An analytical method for characterizing the damage evolution has been established.5) A nonlinear rheological constitutive equation was proposed based on considerations of the grain-boundary sliding and grain interlocking of polycrystalline ceramics with grain-boundary melt at elevated temperatures.6) An experimental apparatus was designed for examining viscoelastic behavior of polycrystalline materials at elevated temperatures up to 1600ﾟC.A novel test specimen geometry (double shear geometry) under compressive loading mode makes possible to conduct rheological testing under simple shear deformation. An experimental scrutiny confirmed that the constituteve equation proposed in Item 5) quantitatively predicts the nonlinear viscoelastic behavior associated with grain-boundary sliding and grain interlocking.7) Toughening processes and mechanisms have been examined via experimental as well as theoretical studies on the mixed-mode fracture and R-curve behavior of several types of ceramics. A novel test technique and a fracture mechanics-based size-effect law were proposed to estimate process zone/wake zone sizes.

1)根据压痕接触力学的能量原理，定义并推导了脆性和延性这两个材料特征参数。脆性/延性参数为脆性材料的可加工性提供了一个定量的表征手段。2）设计了一套脆性/延性参数和压痕损伤程度的表征装置，400立方厘米.3）对高温下脆性材料的粘弹性压痕接触变形进行了理论分析和实验研究。温度利用压痕滞后能表征了材料表面变形的粘弹性行为。4）利用声显微镜研究了压痕接触引起的材料表面损伤。5）考虑高温下晶界熔融多晶陶瓷的晶界滑移和晶粒互锁，建立了非线性流变本构方程设计了一种实验装置，用于在高达1600 ℃的高温下检查多晶材料的粘弹性行为。在压缩加载模式下的双剪切几何形状（双剪切几何形状）使得在简单剪切变形下进行流变测试成为可能。实验研究证实，第5项中提出的本构方程定量地预测了与晶界滑动和晶粒互锁相关的非线性粘弹性行为。7）通过对几种陶瓷的混合型断裂和R曲线行为的实验和理论研究，研究了增韧过程和机理。提出了一种新的测试技术和基于断裂力学的尺寸效应定律来估计过程区/尾流区尺寸。

项目成果

M.Suganuma: "Scanning Acoustic Microscopy of Indentation Damage in Y_2O_3-Stabilized Tetragonal Zirconia" J.Am.Ceram.Soc.78 [11]. 2889-2896 (1995)

M.Suganuma：“Y_2O_3 稳定的四方氧化锆中压痕损伤的扫描声学显微镜”J.Am.Ceram.Soc.78 [11]。

Motohiro Suganuma: "Scanning Acoustic Microscopy of Indentation Damage in Y_2O_3Stabilized Tetragonal Zirconia" J. American Ceramic Society. 78. 2889-2896 (1995)

Motohiro Suganuma：“Y_2O_3稳定四方氧化锆中压痕损伤的扫描声学显微镜”J.美国陶瓷学会。

Ming Li: "Mixed-Mode Fracture of Ceramics in Asymmetric Four-Point Bending" J.American Ceramic Society. 79・10. 2718-2726 (1996)

李明：“不对称四点弯曲陶瓷的混合模式断裂”，美国陶瓷学会 79・10（1996）。

M.Li: "Mixed-Mode Fracture of Ceramics in Asymmetric Four-Point Bending : Effect of Crack-Face Grain Interlocking/Bridging" J.Am.Ceram.Soc.79 [10]. 2718-2726 (1996)

M.Li：“不对称四点弯曲陶瓷的混合模式断裂：裂纹面晶粒互锁/桥接的影响”J.Am.Ceram.Soc.79 [10]。

Motohiro Suganuma: "Scanning Acoustic Microscopy of Indentation Damage in Y_2O_3-Stabilized Tetragonal Zirconia" J.American Ceramic Society. 78・11. 2889-2896 (1995)

Motohiro Suganuma：“Y_2O_3 稳定的四方氧化锆中压痕损伤的扫描声学显微镜”，美国陶瓷学会 78・11（1995 年）。