Small-Scale Additive Friction Stir Deposition of Aerospace Grade Aluminum
Abstract
The proposed program will explore the process fundamentals underlying small-scale additive friction stir deposition of aerospace grade aluminum, AA7050, onto flat AA7050 substrates. By integrating in-situ thermal and mechanical monitoring with interface and material characterization, the main research objective is to develop an in-depth, quantitative understanding of the linkages between the processing condition and resulting quality/properties of the as-deposited AA7050. Using the unique miniaturized additive friction stir deposition facility built in the PIs laboratory, the thermomechanical processing condition can be controlled using the tool rotation rate, feed rate, tool travel velocity, and tilting angle, in which in-situ monitoring will provide insights into the deposition temperature, material flow, pressure, and shear stress at the tool/material interface. Given the strong potential for portable structural repair applications, the key quality metrics and properties include (i) the interface bonding and flash width; (ii) the impurity retention and accumulation caused by lubricant; (iii) the dynamic precipitate evolution in AA7050 deposit/AA7050 substrate and the resulting local mechanical properties.The project is organized into five major tasks and a number of interrelated subtasks, including (Task 1) Control and characterize the thermomechanical processing condition via in-situ monitoring; (Task 2) Understand the process influences on the non-bonded interface width; (Task 3) Understand the lubricant retention and accumulation; (Task 4) Understand the precipitate evolution and local mechanical properties in the as-deposited AA7050 and substrate; (Task 5). Establish the process - thermomechanical condition- quality/ properties linkages. The composition, phase, microstructure, and mechanical properties of theas-deposited AA7050 and substrate will be characterized accordingly.The proposed fundamental program is motivated by the perspective of using portable,small-scale additive friction stir deposition to enable high-performance structural repair of airframes and other platforms for NAVAIR in the future. The knowledge gained from this program will allow for process optimization and can be leveraged to explore depositions for a wide variety of repair geometries, such as deposition onto dissimilar substrates, curved substrates, and substrates with divots or holes. The program serves as a crucial milestone in ensuring superior post-repair quality and performance, laying the foundation for NAVAIR to substantially save the time and cost on repairs, while increasing the lifespan of aircraft.The abstract is Approved for Public Release by the applicant.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 08, 2024
- Source ID
- N000142412181
Entities
People
- Hang Yu
Organizations
- Office of Naval Research
- United States Navy
- Virginia Tech