BRIGE: "Smart" Toughness Enhancement in Metal-Matrix Composites: Linking Structure, Properties and Design

该奖项的研究目标是确定形状记忆合金增强金属基复合材料变形过程中发生的相变与断裂韧性之间的组织-性能关系。金属镁基复合材料将制备两种断裂韧性试样，一种是用假弹性丝增强，另一种是用形状记忆合金丝增强。通过使用电阻率测量，在j积分测试期间将连续监测导线中的相变。同时，对改性单纤维拉拔试样进行试验，建立基体/增强体界面强度与复合韧性之间的关系。如果成功，本研究结果将导致金属基复合材料断裂韧性的提高，特别是自修复合金复合材料。设计和开发一种能够在结构损坏时自我修复的轻质自愈合金复合材料，对于目前无法在服役中修复的系统至关重要。这项工作的主要目标是利用一种机械方法来识别和模拟自适应微结构在智能材料中的增强作用。金属基复合材料。这提供了一个机会和一种方法来提高金属的机械性能，目前表现出有限的断裂韧性，通过加工和增强这些材料的自适应元素。所提出的工作为高比强度自愈结构金属的发展提供了重大贡献，这种结构金属可以使用形状记忆合金线增强韧化。该计划的一个组成部分是通过针对所有年级学生的几项教育举措来增强和促进多样性。

The research objective of this award is to identify the structure-property relationship between the phase transformations occurring during the deformation of a metal-matrix composite reinforced with shape memory alloys and fracture toughness. Magnesium metal-matrix composites will be fabricated into two types of fracture toughness specimens, one reinforced with pseudoelastic wires and the other with shape memory alloy wires. The phase transformations in the wires will be continuously monitored during J-integral testing through the use of electrical resistivity measurements. Concurrently, modified single fiber pullout specimens will be tested to establish a relationship between the matrix/reinforcement interfacial strength and composite toughness.If successful, the results of this research will lead to improvements in the fracture toughness of metal-matrix composites, specifically self-healing alloy composites. The design and development of a light-weight self-healing alloy composite that can repair itself in response to structural damage is critical in systems that are at present impractical to repair in service. The primary goal of this work is to utilize a mechanistic approach to identify and model the role of adaptive microstructures as reinforcements in ?smart? metal-matrix composites. This provides the opportunity and a methodology to enhance the mechanical properties of metals that currently demonstrate limited fracture toughness by processing and reinforcing these materials with adaptive elements. The proposed work provides a significant contribution towards the development of high specific strength self-healing structural metals that can be toughened using shape memory alloy wire reinforcements. An integral part of this program is the enhancement and promotion of diversity using several education initiatives targeted to students at all grade levels.