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，片状增强陶瓷复合材料已成为许多结构应用中晶须和纤维增强材料的可行替代品。 人们认识到，增强相和基质/片层界面的某些特征将有利于改善韧性行为，例如，片层/基质界面处易于脱粘、高片层体积分数，然而详细的系统研究是有限的。 根据里哈伊大学最近开展的工作，人们相信，一种由涂有六铝酸钙（CA6）的氧化铝片组成的新型复合材料系统有可能超越传统片状复合材料的性能。 CA6 具有多种特性，使其非常适合所提出的应用。 其中包括采用外延关系，使 CA6 的弱基底解​​理面与 (0001) α-氧化铝片晶面平行排列，有利于脱粘的热膨胀系数值，以及与氧化铝的热力学稳定性。 提出了块状复合材料和界面结构的机械表征。 加工和机械测试将通过使用 TEM 对脱粘界面进行高分辨率研究来补充。该计划的目标有多个。 目标之一是确定复合材料系统的加工和微观结构参数，以优化机械性能。然而，在更基本的层面上，所提出的程序将实现界面结构、界面的韧性和强度以及块体复合材料的机械行为之间的直接关联。 %%%% 近年来，片状增强陶瓷复合材料已成为许多结构应用中晶须和纤维增强材料的可行替代品。 人们认识到，增强相和基体/片状界面的某些特征将有利于改善韧性行为，但详细的系统研究有限。 根据里哈伊大学最近开展的工作，人们相信，一种由涂有六铝酸钙（CA6）的氧化铝片组成的新型复合材料系统有可能超越传统片状复合材料的性能。 该计划的目标有多个。 目标之一是确定复合材料系统的加工和微观结构参数，以优化机械性能。 然而，在更基本的层面上，所提出的程序将实现界面结构、界面的韧性和强度以及块体复合材料的机械行为之间的直接关联。 ***