Development of a 7XXX-series master alloy for cold spray deposited solid state structural repairs
Abstract
This project will provide a comprehensive investigation of the effect of composition on behavior of cold gas dynamic spray (cold spray) deposited material to develop a performance-driven Al-Zn-Cu-Mg master alloy for solid state structural repair (S3R) of Navy-relevant 7XXX-series Al alloys. Cold spray is an emerging technology capable of producing fully dense deposits at high rates in ambientatmospheres for in situ dimensional and structural repair. However, much of the current work on S3R cold spray involves deposition of material that is chemically matched to the target substrate for repair. Recent, previous work by the PIs on cold spray repair of Naval Al-Mg alloys showed that alloy composition could effectively tune deposition efficiency, deposit hardness, and susceptibility to localized corrosion, all while maintaining densities of greater than 99.97%. In this project we will explore the effect of alloy chemistry on deposition characteristics, microstructure, and properties for Al-Zn-Mg-Cu feedstock intended for repair of multiple 7XXX-series substrates, such as AA7075, AA7050, AA7085, etc. A design of experiments approach will generate an optimization model based on high-throughput testing of fourteen alloy compositions. Down-selected alloys will be further tested to determine the processing-structure-property relationships of larger-scale cold spray deposits to further refine the optimization model. Properties of interest include quasi-static tensile and fatigue mechanical behavior, bond strength, and corrosion performance. Since the goal of an S3R master alloy would be broad application to multiple substrates and repair scenarios, a final down-selected alloy will be tested in simulated repair geometries on a range of AA7XXX substrates to assess performance and to identify compatible and incompatible substrates for repair. Additionally, the effect of non-essential and impurity elements, such as Fe and Si, on cold spray deposit propertieswill be assessed and fed into the optimization model. Ultimately, this project will assess the process-structure-property-performance relationships of more than nineteen feedstock compositions and will propose an S3R master alloy applicable to repair of an assortment of Navy-relevant AA7XXX alloy structures.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 13, 2023
- Source ID
- N000142312889
Entities
People
- Gregory Kubacki
Organizations
- Office of Naval Research
- United States Navy
- University of Alabama