Publication Date

12-17-2020

Department

Ames Laboratory; Electrical and Computer Engineering; Materials Science and Engineering

Campus Units

Ames Laboratory, Electrical and Computer Engineering, Materials Science and Engineering

OSTI ID+

1756044

Report Number

IS-J 10391

DOI

10.1016/j.actamat.2020.116575

Journal Title

Acta Materialia

Volume Number

205

First Page

116575

Abstract

Compared to the widely used Fe-3.2wt%Si steel, Fe-6.5wt%Si has superior electric and magnetic properties, including higher electrical resistivity, lower iron loss, higher permeability, and near zero magnetostriction. However, Fe-6.5wt%Si sheet is difficult to produce using traditional manufacturing processes as the high silicon content favors the formation of ordered phases that embrittle the material. Fortunately, these ordered phases can be suppressed if the alloy is cooled fast enough from a high temperature kinetically trapping the disordered solid solution or amorphous state. Planar flow casting is known for its rapid solidification rate. In order to consider it as a viable method to manufacture ductile Fe-6.5wt%Si sheets, the effect of cooling rate on physical properties of Fe-6.5wt%Si alloy are systematically investigated. In this work, various cooling rates are achieved by changing melt-spin wheel speeds, which significantly affect the solidification temperature profile and have profound effects on ordering, microstructures, textures, hardness, and magnetic properties. High cooling rates result in refined grains, reduced ordering, enhanced <100> out of the plane texture, decreased hardness, and increased coercivity. This study shows a critical cooling rate at ~1.7 × 105 K/s, corresponding to a tangential wheel speed of 5-7 m/s, below which the hardness significantly increases in agreement with the sudden increase of the ordered phases that causes the material embrittlement.

DOE Contract Number(s)

AC02-07CH11358; EE0007794

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Friday, December 17, 2021

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