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Title: Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE)

Abstract

Shear Assisted Processing and Extrusion (ShAPE) -a novel processing route that combines high shear and extrusion conditions- was evaluated as a processing method to densify melt spun magnesium alloy (AZ91E) flake materials. This study illustrates the microstructural regimes and transitions in crystallographic texture that occur as a result of applying simultaneous linear and rotational shear during extrusion. Characterization of the flake precursor and extruded tube was performed using scanning and transmission electron microscopy, x-ray diffraction and microindentation techniques. Results show a unique transition in the orientation of basal texture development. Despite the high temperatures involved during processing, uniform grain refinement and material homogenization are observed. These results forecast the ability to implement the ShAPE processing approach for a broader range of materials with novel microstructures and high performance.

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1368121
Report Number(s):
PNNL-SA-122981
Journal ID: ISSN 0921-5093; 49427
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing; Journal Volume: 701; Journal Issue: C
Country of Publication:
United States
Language:
English
Subject:
Rapid Solidification; Magnesium Alloy; Microstructure; Friction Consolidation Extrusion; EBSD; ShAPE; Environmental Molecular Sciences Laboratory

Citation Formats

Overman, N. R., Whalen, S. A., Bowden, M. E., Olszta, M. J., Kruska, K., Clark, T., Stevens, E. L., Darsell, J. T., Joshi, V. V., Jiang, X., Mattlin, K. F., and Mathaudhu, S. N. Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE). United States: N. p., 2017. Web. doi:10.1016/j.msea.2017.06.062.
Overman, N. R., Whalen, S. A., Bowden, M. E., Olszta, M. J., Kruska, K., Clark, T., Stevens, E. L., Darsell, J. T., Joshi, V. V., Jiang, X., Mattlin, K. F., & Mathaudhu, S. N. Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE). United States. doi:10.1016/j.msea.2017.06.062.
Overman, N. R., Whalen, S. A., Bowden, M. E., Olszta, M. J., Kruska, K., Clark, T., Stevens, E. L., Darsell, J. T., Joshi, V. V., Jiang, X., Mattlin, K. F., and Mathaudhu, S. N. Sat . "Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE)". United States. doi:10.1016/j.msea.2017.06.062.
@article{osti_1368121,
title = {Homogenization and texture development in rapidly solidified AZ91E consolidated by Shear Assisted Processing and Extrusion (ShAPE)},
author = {Overman, N. R. and Whalen, S. A. and Bowden, M. E. and Olszta, M. J. and Kruska, K. and Clark, T. and Stevens, E. L. and Darsell, J. T. and Joshi, V. V. and Jiang, X. and Mattlin, K. F. and Mathaudhu, S. N.},
abstractNote = {Shear Assisted Processing and Extrusion (ShAPE) -a novel processing route that combines high shear and extrusion conditions- was evaluated as a processing method to densify melt spun magnesium alloy (AZ91E) flake materials. This study illustrates the microstructural regimes and transitions in crystallographic texture that occur as a result of applying simultaneous linear and rotational shear during extrusion. Characterization of the flake precursor and extruded tube was performed using scanning and transmission electron microscopy, x-ray diffraction and microindentation techniques. Results show a unique transition in the orientation of basal texture development. Despite the high temperatures involved during processing, uniform grain refinement and material homogenization are observed. These results forecast the ability to implement the ShAPE processing approach for a broader range of materials with novel microstructures and high performance.},
doi = {10.1016/j.msea.2017.06.062},
journal = {Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing},
number = C,
volume = 701,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}
  • The rapid solidification of powder results in a high cooling rate which leads to microstructural refinement and extended solid solubility of alloying elements and thereby precipitation of fine dispersive phases during powder solidification and consolidation. During the last decade considerable research work has been done in the development of high temperature powder metallurgy aluminum alloys capable of competing with titanium alloys on a specific strength basis with the use of rapid solidification processes. The Al-Fe-V-Si family of alloys are one of the most promising on a basis of elevated temperature strength, stiffness and thermal stability. In previous studies, the Al-Fe-V-Simore » alloys were usually produced by melt spinning (both jet casting and planar flow casting) followed by consolidation of the resulting ribbons. The aim of the present study was to investigate the microstructural development of atomized Al-Fe-V-Si alloy powder during consolidation by vacuum hot pressing (VHP), extrusion and rolling.« less
  • Shear Assisted Processing and Extrusion (ShAPE) has been scaled-up and applied to direct extrusion of thin-walled magnesium tubing. Using ShAPE, billets of ZK60A-T5 were directly extruded into round tubes having an outer diameter of 50.8 mm and wall thickness of 1.52 mm. The severe shearing conditions inherent to ShAPE resulted in microstructural refinement with an average grain size of 3.8μm measured at the midpoint of the tube wall. Tensile testing per ATSM E-8 on specimens oriented parallel to the extrusion direction gave an ultimate tensile strength of 254.4 MPa and elongation of 20.1%. Specimens tested perpendicular to the extrusion directionmore » had an ultimate tensile strength of 297.2 MPa and elongation of 25.0%. Due to material flow effects resulting from the simultaneous linear and rotational shear intrinsic to ShAPE, ram force and electrical power consumption during extrusion were just 40 kN and 11.5 kW respectively. This represents a significant reduction in ram force and power consumption compared to conventional extrusion. As such, there is potential for ShAPE to offer a scalable, lower cost extrusion option with potentially improved bulk mechanical properties.« less
  • In the present investigation, the mechanical properties of an elevated temperature aluminum alloy exhibiting two different size distributions was evaluated after extrusion processing at 400 C. The alloy powder with a target composition of Al-8 wt.% Fe-4 wt.% Ce was produced under different atomizing conditions. The consolidation process using extrusion was found to be more beneficial for finer powder size distribution in terms of elevated temperature mechanical properties because of the retention of a more desirable metastable phase.
  • In the present investigation a potential aerospace aluminum alloy made from atomized powder was subjected to microstructural investigation. Samples exhibiting varied powder size distribution, due to differences in atomizing conditions employed in powder production, were studied. The alloy having a target composition of Al-8 wt.% Fe-4wt.%Ce was characterized using transmission electron microscopy and X-ray diffractometry. The fine powder size distribution was found to be more desirable from the mechanical properties point of view due to the retention of metastable phases.
  • No abstract prepared.