Session: 04-12-02: Design of Materials and Discovery of Constitutive Models Linking Process-Structure-Property-Performance Relationships

Paper Number: 165472

Establishing Process-Structure-Property-Performance Relationships: Icme Modeling of Additive Friction Stir Deposition Repairs in Aluminum Alloy 7050-T7451 

Additive Friction Stir Deposition (AFSD) has emerged as an efficient solid-state repair methodology, gaining increasing interest, particularly for aluminum alloys used in aerospace applications. Traditional repair methods often introduce defects such as porosity, cracks, or undesirable residual stresses, which can degrade the structural integrity. AFSD enables localized deposition while maintaining a refined microstructure, making it a promising solution for repairing through-holes and localized damage in critical aerospace components. Despite its advantages, understanding the microstructural evolution and mechanical behavior of AFSD repairs remains a challenge, requiring integrated modeling approaches to establish process–structure–property–performance (PSPP) relationships. This study systematically investigates different processing strategies for AFSD hole repairs and develops an Integrated Computational Materials Engineering (ICME) framework to predict the resulting microstructural transformations and mechanical performance in AA7050-T7451. The work focuses on two common AFSD repair techniques: the Stationary Tool Head (STH) and Moving Tool Head (MTH) approaches, assessing their effects on precipitation evolution and different strengthening mechanisms. To model the repair process, COMSOL thermal simulations were conducted to capture in-depth temperature profiles at various depths within the repair zone. These computational results were validated against in-situ time–temperature measurements obtained through embedded thermocouples. The validated thermal histories served as direct input for precipitation modeling using the TC-Prisma module of Thermo-Calc software. This approach enabled the prediction of phase transformations, particularly the dissolution and reprecipitation of strengthening phases such as η and η' during and after deposition. Finally, a physics-based yield strength model was developed to correlate the evolving precipitation characteristics with mechanical properties. The model, based on dislocation-particle interaction, incorporates strengthening contributions from bypassing mechanism and shearing mechanisms, providing insights into how AFSD process parameters influence the final strength of the repaired region. A comparative analysis between the STH and MTH techniques revealed variations in the volume fraction and size distribution of precipitates, directly influencing the mechanical properties. Notably, the MTH approach exhibited a lower yield strength due to a reduced volume fraction of strengthening precipitates, whereas the STH approach comparatively retained a higher volume fraction, resulting in superior yield strength. The findings of this study establish a direct linkage between AFSD process parameters and the resulting mechanical properties, providing a predictive pathway for optimizing repair strategies in aerospace alloys. Integration of process, microstructural, and property modeling within an ICME framework allows for advancements in the understanding of PSPP relationships in AFSD-repaired components, contributing to the broader goal of enabling reliable, high-performance repairs for structural applications exceeding the traditional fusion-based repair methods.

Presenting Author: Hamza Jabbar The University of Alabama

Presenting Author Biography: Hamza Jabbar is a Graduate Research Assistant in the Materials Modeling, Design, and Informatics (MDI) Lab at The University of Alabama. As a PhD student, his research focuses on developing ICME models to establish process-structure-property relationships in materials using CALPHAD-based microstructural modeling and physics-based property predictions, with an emphasis on solid-state additive manufacturing.

Authors:

Hamza Jabbar The University of Alabama
Abigail Taylor Triton Systems, Inc
Farid Biniyazan The University of Alabama
Jack Grubbs Triton Systems, Inc
Bryer Sousa Triton Systems, Inc
Sadie Beck The University of Alabama
Qiaofu Zhang The University of Alabama