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Title: Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy

Abstract

Rapid solidification (RS) processing, as a production method, offers a variety of unique properties based on far-from-equilibrium microstructures obtained through rapid cooling rates. In this study, we seek to investigate the microstructures and properties of a novel Al-alloy specifically designed for high temperature mechanical stability. Synthesis of, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} (wt.%), was performed by two approaches: rotating cup atomization (“shot”) and melt spinning (“flake”). These methods were chosen because of their ability to produce alloys with tailored microstructures due to their inherent differences in cooling rate. The as-solidified precursor materials were microstructurally characterized with electron microscopy. The results show that the higher cooling rate flake material exhibited the formation of nanocrystalline regions as well additional phase morphologies not seen in the shot material. Secondary dendritic branching in the flake material was on the order of 0.1–0.25 μm whereas branching in the shot material was 0.5–1.0 μm. Consolidated and extruded material from both precursor materials was mechanically evaluated at both ambient and high (300 °C) temperature. The consolidated RS flake material is shown to exhibit higher strengths than the shot material. The ultimate tensile strength of the melt spun flake was reported as 544.2 MPa at room temperature andmore » 298.0 MPa at 300 °C. These results forecast the ability to design alloys and processing approaches with unique non-equilibrium microstructures with robust mechanical properties at elevated temperatures. - Highlights: • A novel alloy, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} was fabricated by rapid solidification. • Room temperature yield strength exceeded 500 MPa. • Elevated temperature (300 °C) yield strength exceeded 275 MPa. • Forging, after extrusion of the alloy resulted in microstructural coarsening. • Decreased strength and ductility was identified as a result of forging.« less

Authors:
 [1];  [1];  [2]; ; ;  [1]
  1. Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22587100
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 112; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM ALLOYS; DUCTILITY; ELECTRON MICROSCOPY; MICROSTRUCTURE; MORPHOLOGY; NANOSTRUCTURES; PRESSURE RANGE MEGA PA; SOLIDIFICATION; YIELD STRENGTH

Citation Formats

Overman, N.R., E-mail: Nicole.Overman@pnnl.gov, Mathaudhu, S.N., University of California, Riverside, 3401 Watkins Dr., Riverside, CA 92521, Choi, J.P., Roosendaal, T.J., and Pitman, S. Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy. United States: N. p., 2016. Web. doi:10.1016/J.MATCHAR.2015.12.015.
Overman, N.R., E-mail: Nicole.Overman@pnnl.gov, Mathaudhu, S.N., University of California, Riverside, 3401 Watkins Dr., Riverside, CA 92521, Choi, J.P., Roosendaal, T.J., & Pitman, S. Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy. United States. doi:10.1016/J.MATCHAR.2015.12.015.
Overman, N.R., E-mail: Nicole.Overman@pnnl.gov, Mathaudhu, S.N., University of California, Riverside, 3401 Watkins Dr., Riverside, CA 92521, Choi, J.P., Roosendaal, T.J., and Pitman, S. Mon . "Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy". United States. doi:10.1016/J.MATCHAR.2015.12.015.
@article{osti_22587100,
title = {Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy},
author = {Overman, N.R., E-mail: Nicole.Overman@pnnl.gov and Mathaudhu, S.N. and University of California, Riverside, 3401 Watkins Dr., Riverside, CA 92521 and Choi, J.P. and Roosendaal, T.J. and Pitman, S.},
abstractNote = {Rapid solidification (RS) processing, as a production method, offers a variety of unique properties based on far-from-equilibrium microstructures obtained through rapid cooling rates. In this study, we seek to investigate the microstructures and properties of a novel Al-alloy specifically designed for high temperature mechanical stability. Synthesis of, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} (wt.%), was performed by two approaches: rotating cup atomization (“shot”) and melt spinning (“flake”). These methods were chosen because of their ability to produce alloys with tailored microstructures due to their inherent differences in cooling rate. The as-solidified precursor materials were microstructurally characterized with electron microscopy. The results show that the higher cooling rate flake material exhibited the formation of nanocrystalline regions as well additional phase morphologies not seen in the shot material. Secondary dendritic branching in the flake material was on the order of 0.1–0.25 μm whereas branching in the shot material was 0.5–1.0 μm. Consolidated and extruded material from both precursor materials was mechanically evaluated at both ambient and high (300 °C) temperature. The consolidated RS flake material is shown to exhibit higher strengths than the shot material. The ultimate tensile strength of the melt spun flake was reported as 544.2 MPa at room temperature and 298.0 MPa at 300 °C. These results forecast the ability to design alloys and processing approaches with unique non-equilibrium microstructures with robust mechanical properties at elevated temperatures. - Highlights: • A novel alloy, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} was fabricated by rapid solidification. • Room temperature yield strength exceeded 500 MPa. • Elevated temperature (300 °C) yield strength exceeded 275 MPa. • Forging, after extrusion of the alloy resulted in microstructural coarsening. • Decreased strength and ductility was identified as a result of forging.},
doi = {10.1016/J.MATCHAR.2015.12.015},
journal = {Materials Characterization},
number = ,
volume = 112,
place = {United States},
year = {Mon Feb 15 00:00:00 EST 2016},
month = {Mon Feb 15 00:00:00 EST 2016}
}