Novel Platelet Composites for Improved Mechanical Behavior

用于改善机械性能的新型血小板复合材料

• 批准号: 9616668
• 负责人: Helen Chan
• 金额: $ 33.74万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-15 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9616668&HistoricalAwards=false
• 关键词: Novel; Platelet; Composites; Improved; Mechanical

9616668 Chan In recent years, platelet reinforced ceramic composites have emerged as viable alternatives to whisker and fiber reinforced materials for many structural applications. It is recognized that there are certain characteristics of the reinforcement phase and the matrix/platelet interface which will favor improved toughness behavior, e.g., ease of debonding at the platelet/matrix interface, high platelet volume fraction, however detailed systematic study has been limited. Based on recent work carried out at Lehigh, it is believed that a novel composite system consisting of alumina platelets coated with calcium hexaluminate (CA6) has the potential to surpass the properties of conventional platelet composites. CA6 exhibits several characteristics which make it exceptionally well-suited for the proposed application. These include the adoption of an epitaxial relationship such that the weak basal cleavage planes of CA6 align parallel to the (0001) a-alumina platelet faces, values of thermal coefficients of expansion which favor debonding, and thermodynamic stability with alumina. Mechanical characterization of both the bulk composites and the interface structures is proposed. The processing and mechanical testing will be complemented by high resolution study of debonded interfaces using TEM. The goals of the program are several-fold. One aim will be to determine the processing and microstructural parameters of the composite system which optimize the mechanical properties. On a more fundamental level, however, the proposed program will enable the direct correlation between interfacial structure, the toughness, and strength of the interface, and the mechanical behavior of the bulk composite. %%%% In recent years, platelet reinforced ceramic composites have emerged as viable alternatives to whisker and fiber reinforced materials for many structural applications. It is recognized that there are certain characteristics of the reinforcement phase and the matrix/platelet interface which will favor improved toughness behavior, however detailed systematic study has been limited. Based on recent work carried out at Lehigh, it is believed that a novel composite system consisting of alumina platelets coated with calcium hexaluminate (CA6) has the potential to surpass the properties of conventional platelet composites. The goals of the program are several-fold. One aim will be to determine the processing and microstructural parameters of the composite system which optimize the mechanical properties. On a more fundamental level, however, the proposed program will enable the direct correlation between interfacial structure, the toughness, and strength of the interface, and the mechanical behavior of the bulk composite. ***

9616668 Chan近年来，血小板增强的陶瓷复合材料已成为许多结构应用的晶须和纤维增强材料的可行替代品。 人们认识到，加固阶段和基质/血小板界面具有某些特征，这将有利于改善韧性行为，例如，在血小板/基质界面上易于脱键，高血小板体积分数高，但是详细的系统研究受到限制。 根据在Lehigh进行的最新工作，据信，由涂有六钙钙钙酸钙（CA6）的氧化铝血小板组成的新型复合系统有可能超过常规血小板复合材料的特性。 CA6具有多种特征，使其非常适合拟议的应用。 其中包括采用外延关系，使CA6的弱基底裂解平面平行于（0001）A-氧化铝小血小板面，有利于脱膜的热系数的值，以及与铝的热力学稳定性。 提出了散装复合材料和界面结构的机械表征。 使用TEM对剥离界面的高分辨率研究将补充处理和机械测试。该计划的目标是多个。 一个目的是确定优化机械性能的复合系统的处理和微观结构参数。然而，从更基本的角度来看，所提出的程序将使界面结构，界面的韧性和强度与大量复合材料的机械行为之间的直接相关性。 %%%%近年来，血小板增强的陶瓷复合材料已成为许多结构应用的晶须和纤维增强材料的可行替代品。 人们认识到，增强阶段和基质/血小板界面的某些特征将有利于改善韧性行为，但是详细的系统研究受到限制。 根据在Lehigh进行的最新工作，据信，由涂有六钙钙钙酸钙（CA6）的氧化铝血小板组成的新型复合系统有可能超过常规血小板复合材料的特性。 该计划的目标是多个。 一个目的是确定优化机械性能的复合系统的处理和微观结构参数。 然而，从更基本的角度来看，所提出的程序将使界面结构，界面的韧性和强度与大量复合材料的机械行为之间的直接相关性。 ***