The effects of processing condition and fatigue on ultra-large self thermal plastic deformation in NiTi shape memory alloy fiber actuated aluminum metal matrix composites

材料加工-实验测试-数学建模耦合程序将研究加工时间-温度条件的变化如何影响NiTi形状记忆合金纤维驱动铝金属基复合材料的自热塑性响应强度，并将研究如何发展材料中的很高内应力影响机械疲劳行为。 初步研究结果表明，经过适当加工和制备的NiTi形状记忆合金纤维致动铝基复合材料（SMA-MMC）在加热条件下将表现出非常大的自施加热塑性压缩变形。 不幸的是，目前对材料的加工敏感性和热机械疲劳行为知之甚少。 因此，我们提出了以下三个主要任务：任务1：系统地测量如何控制高温热压固结工艺条件的变化影响形状恢复的SMA-MMC，并确定的机制（S）负责的材料性能变化。 任务2：执行拉伸循环疲劳耐久性研究，确定材料中的疲劳损伤发展过程。 任务三：对材料的自热塑性响应进行数学建模，以适应基体强度、基体流动特性、纤维体积分数、纤维转变特性和温度历史的一般变化。 该计划的总体目标是为安全和成本关键的商业和军事应用的科学发展提供定量设计工具。

A coupled materials processing - experimental testing - mathematical modeling program will study how variations in processing time-temperature conditions effect the strength of the self thermal-plastic response of NiTi shape memory alloy fiber actuated aluminum metal matrix composites, and will investigate how the development of very high internal stresses in the material influence mechanical fatigue behavior. Preliminary results have shown that a properly processed and prepared NiTi shape memory alloy fiber actuated aluminum metal matrix composite (SMA-MMC) will exhibit very large, self imposed thermal-plastic compressive deformation under heating. Unfortunately, very little is presently known about the processing sensitivity and thermo-mechanical-fatigue behavior of the material. We therefore propose the following three major tasks: Task 1: Systematically measure how controlled variations in high temperature hot press consolidation processing conditions effect the shape recovery of the resulting SMA-MMC, and determine the mechanism(s) responsible for the material performance changes. Task 2: Perform a tensile cycle fatigue endurance study, identifying the fatigue damage development process in the material. Task 3: Mathematically model the self thermal plastic response of the material accommodating general variations in matrix strength, matrix flow properties, fiber volume fraction, fiber transformation properties, and temperature histories. The overall goal of the program is to provide a quantitative design tool for the scientific development of safety and cost critical commercial and military applications.