Papers

Peer-reviewed Last author
Feb 23, 2021

Managing both high strength and thermal conductivity of a laser powder bed fused Al–2.5Fe binary alloy: Effect of annealing on microstructure

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
  • Xing Qi
  • ,
  • Naoki Takata
  • ,
  • Asuka Suzuki
  • ,
  • Makoto Kobashi
  • ,
  • Masaki Kato

Volume
805
Number
First page
140591
Last page
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.1016/j.msea.2020.140591
Publisher
ELSEVIER SCIENCE SA

The microstructure of Al-2.5Fe (wt%) binary alloy samples additively manufactured by laser powder bed fusion (L-PBF) was systematically characterized, and its change due to subsequent annealing at 300 degrees C and 500 degrees C was examined. The as-fabricated samples featured homogeneous distribution of numerous fine particles of the metastable Al6Fe phase in the solidification microstructure where melt pools formed, and a relatively coarsened cellular structure was observed around the boundaries between the melt pools formed at different locations (melt pool boundaries). After the annealing at 300 degrees C, a slight growth of the nano-sized Al6Fe phase occurred, and coarsened plate-like.-Al13Fe4 phases were locally formed in the cellular structure at melt pool boundaries. Annealing at 500 degrees C induced a pronounced transformation of the metastable Al6Fe phase to the stable.-Al13Fe4 phase in the microstructure where melt pools formed, although no significant change in the microstructure of the a-Al matrix was detected. The thermal conductivity and tensile properties of as-fabricated and subsequently annealed specimens were measured. The as-fabricated specimens exhibited a high tensile strength of similar to 320 MPa and a thermal conductivity of similar to 150 W m(-1) K-1. Annealing at 300 degrees C improved the thermal conductivity to similar to 185 W m(-1) K-1 without a loss of tensile strength, whereas annealing at 500 degrees C significantly decreased the tensile strength. These results are utilized to discuss a balance between mechanical properties and thermal conductivity, which provided novel insights for managing both high strength and thermal conductivity of L-PBFbuilt Al-Fe binary alloys by controlling microstructure.

Link information
DOI
https://doi.org/10.1016/j.msea.2020.140591
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000667276200014&DestApp=WOS_CPL
ID information
  • DOI : 10.1016/j.msea.2020.140591
  • ISSN : 0921-5093
  • eISSN : 1873-4936
  • Web of Science ID : WOS:000667276200014

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