Fundamentals of Bonding in Kinetic Consolidation Processes

这笔赠款提供资金，用于探索和阐明在动态固结过程中颗粒之间发生的基本结合机制，如超声波制造和冷喷射沉积。所开发的模型将描述影响固结材料的结构、性能和性能的颗粒相互作用的物理方面。此外，将在一系列材料系统中追求特定的结合标准，以改进当前的技术以及使用新材料的关键设计工具。对冷喷涂过程中颗粒碰撞的计算模拟将确定应力和温度的分布。这些数据将与在相同条件下实验撞击的粒子的高分辨率金相观察结果相关联。此外，对超声固结产生的样品进行的平行显微研究将提供数据，以探索这两种技术之间的相似性，并用更可控的颗粒应力状态测试建模预测。将探索所有试件的力学特性，以建立界面结构-性能关系，并探索这些材料的变形和破坏标准。如果成功，这项研究的结果将有助于改进目前使用的材料，如铝、镁和铜合金的动力学固结过程的设计，并建立工艺条件，使新材料系统得以生产。这项工作的主要目标是确定当受到超音速冲击或超声波振动条件下，接触的颗粒如何发展强大的键。然后，结果可以在输入参数、工具设计、材料选择和前/后处理技术方面指导工业实践。反过来，这可以提高制造效率和机械性能，或者加速将这些材料插入新的应用。拟议的工作还将扩大对高塑性应变率下的冶金热力学和动力学的理解。

This grant provides funding to explore and elucidate fundamental bonding mechanisms that occur between particles in kinetic consolidation processes, such as ultrasonic fabrication and cold spray deposition. The developed models will describe physical aspects of particle interaction affecting structure, properties and performance of consolidated materials. In addition, specific bonding criteria will be pursued in a range of materials systems to improve current techniques as well as critical design tools for usage of new materials. Computational simulations of particle impact during cold spray will identify distributions of stress and temperature. These data will be correlated with high-resolution metallographic observations on particles experimentally impacted under identical conditions. Further, parallel microscopic studies on specimens produced via ultrasonic consolidation will provide data to explore similarities between the two techniques as well as test modeling predictions with a more controllable particle stress state. Mechanical characterization will be explored on all specimens to develop interfacial structure-property relationships and explore deformation and failure criteria in these materials.If successful, the results of this research will lead to improvements in the design of kinetic consolidation processes for currently-used materials such as aluminum, magnesium and copper alloys as well as establish process conditions to enable new materials systems to be produced. The primary goal of this work is to determine how contacting particles develop strong bonds when subjected to supersonic impact or ultrasonic vibratory conditions. Results may then guide industrial practice in input parameters, tool design, material selection, and pre-/post-processing techniques. In turn, this could improve fabrication efficiency and mechanical behavior, or accelerate insertion of these materials into new applications. The proposed work will also expand understanding of metallurgical thermodynamics and kinetics under high plastic strain rates.