Abstract
Scalmalloy® is an Al-Mg-Sc-Zr-Based Alloy Specifically Developed for Additive Manufacturing (AM). This Alloy is Designed for Use with a Direct Aging Treatment, as Recommended by the Manufacturer, Rather Than with a Multistep Treatment, as Often Seen in Conventional Manufacturing. Most Work with Scalmalloy® is Conducted using Powder Bed Rather Than Powder-Fed Processes. This Investigation Seeks to Fill This Knowledge Gap and Expand Beyond Single-Step Aging to Promote an overall Balanced AM-Fabricated Component. for This Study, Directed Energy Deposition (DED)-Fabricated Scalmalloy® Components Were Subjected to Low-Temperature Treatments to Minimize Residual Stresses Inherent in the Material Due to the Layer-By-Layer Build Process. X-Ray Diffraction (XRD) Indicated the Possibility of Stress Minimization While Reducing the Detriment to Mechanical Strength through Lower Temperature Treatments. Microstructural Analyses Consisting of Energy Dispersion Spectroscopy (EDS) and Electron Backscatter Diffraction (EBSD) Revealed the Presence of Grain Growth Detrimentally Affecting the Strength and Elongation Made Possible by Very Small Grains Inherent to AM and Rapid Solidification. Tensile Testing Determined that Treatment at 175 °C for 1 H Provides the Best Relief from the Existing Residual Stresses; However, This is Accompanied by a Diminishment in the Yield and Tensile Strength of 19 and 9.5%, Respectively. It is Noted that Treatment at 175 °C for 2 H Did Not Provide as Great of a Decrease in Residual Stresses, Theorized to Be the Result of Grain Growth and Other Strengthening Mechanisms Further Stressing the Structure; However, the Residual Stresses Are Still Significantly Diminished Compared with the As-Built Condition. Furthermore, a Minimal Reduction of the Tensile Strengths Indicates the Possibility of Finding a Balance between Property Diminishment and Stress State through the Work Proposed Here.
Recommended Citation
R. Boillat-Newport et al., "Heat Treatments for Minimization of Residual Stresses and Maximization of Tensile Strengths of Scalmalloy® Processed Via Directed Energy Deposition," Materials, vol. 17, no. 6, article no. 1333, MDPI, Mar 2024.
The definitive version is available at https://doi.org/10.3390/ma17061333
Department(s)
Mechanical and Aerospace Engineering
Publication Status
Open Access
Keywords and Phrases
additive manufacturing; aluminum; directed energy deposition; laser-based process; residual stresses; Scalmalloy ®; stress relief
International Standard Serial Number (ISSN)
1996-1944
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Mar 2024
Comments
Intelligent Systems Center, Grant CMMI 1625736