Synthesis and Mechanical Properties of Microlaminates Using Ion Beam Assisted Deposition

9411141本工作的目的是探索利用离子束辅助沉积(IBAD)来控制微层压板的微观结构和界面性能。这些结果应该会提供对这些系统中控制强度和韧性的因素的更基本的理解。以Nb/Al_2O_3为模型高温体系，研究了IBAD对延性层的晶粒度、形貌、织构和强度的影响。可以通过控制界面上的取向关系和杂质成分来控制金属-氧化物界面的强度。虽然沉积是在高温(600摄氏度)下进行的，并进行了更高的温度热处理以评估微观结构的稳定性，但力学性能研究的重点是微层压板在常温下的韧性。%该科学方法基于这样一种理念，即离子束辅助沉积改进了对微层压板中单个薄片和界面的结构的控制，从而提高了这些材料作为结构材料和涂层材料的高温应用的韧性和强度。***

9411141 Was The objective of this work is to explore the use of ion beam assisted deposition (IBAD) to control the microstructure and interface properties of microlaminates. The results should provide a more fundamental understanding of factors controlling strength and toughness in these systems. Niobium/alumina is selected as the model, high temperature system to explore IBAD's effect on grain size, morphology, texture and ensuing strength of the ductile layer. It may be possible to control the metal-oxide interface strength by controlling the orientation relationship and the impurity composition at the interface. Although the depositions are done at high temperature (600 degrees C) and still higher temperature annealing is conducted to assess microstructural stability, the focus of the mechanical properties study is the toughness of the microlaminate at ambient temperature. %%% The scientific approach is based on the idea that ion beam assisted deposition provides improved control over the structure of individual lamellae and interfaces in microlaminates, thereby improving the toughness and strength of these materials for high temperature applications as structural and coating materials. ***