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。

基本信息

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

项目摘要

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得出了勃彩和延展性作为特征材料参数。脆性/延展性参数给出了一种定量度量，以表征脆性材料的加工。2）设计用于表征勃起/延性参数的特征和凹痕诱导的损害程度，在室内温度范围从室温到1,400 c.3的范围内的广泛温度范围内，是概述的概述，是概述的概述的概述，可视意的构图，可视线范围的范围。温度。压痕磁滞能成功地用于表征表面变形的粘弹性行为。4）将声学显微镜应用于压痕接触引入的表面损伤。 5）基于对多晶陶瓷的晶粒结构滑动和晶粒互锁的考虑，提出了一种非线性流变组成方程，并在升高的气候下进行了晶粒式熔体。在压缩载荷模式下，在简单剪切变形下进行流变学测试，标本几何形状（双剪切几何形状）可能会进行。实验审查证实，在第5项中提出的构成等效性，定量预测与晶粒 - 边界滑动和谷物互锁相关的非线性粘弹性行为。提出了一种新型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/唤醒区的大小。