Campus Units

Materials Science and Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

2017

Journal or Book Title

Metallurgical and Materials Transactions A

Volume

48

Issue

7

First Page

3594

Last Page

3605

DOI

10.1007/s11661-017-4117-7

Abstract

It is necessary to better understand the composition–processing–microstructure relationships that exist for materials produced by additive manufacturing. To this end, Laser Engineered Net Shaping (LENS™), a type of additive manufacturing, was used to produce a compositionally graded titanium binary model alloy system (Ti-xW specimen (0 ≤ x ≤ 30 wt pct), so that relationships could be made between composition, processing, and the prior beta grain size. Importantly, the thermophysical properties of the Ti-xW, specifically its supercooling parameter (P) and growth restriction factor (Q), are such that grain refinement is expected and was observed. The systematic, combinatorial study of this binary system provides an opportunity to assess the mechanisms by which grain refinement occurs in Ti-based alloys in general, and for additive manufacturing in particular. The operating mechanisms that govern the relationship between composition and grain size are interpreted using a model originally developed for aluminum and magnesium alloys and subsequently applied for titanium alloys. The prior beta grain factor observed and the interpretations of their correlations indicate that tungsten is a good grain refiner and such models are valid to explain the grain-refinement process. By extension, other binary elements or higher order alloy systems with similar thermophysical properties should exhibit similar grain refinement.

Comments

This article is published as Mendoza, Michael Y., Peyman Samimi, David A. Brice, Brian W. Martin, Matt R. Rolchigo, Richard LeSar, and Peter C. Collins. "Microstructures and Grain Refinement of Additive-Manufactured Ti-xW Alloys." Metallurgical and Materials Transactions A (2017): 1-12. doi: 10.1007/s11661-017-4117-7. Posted with permission.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Copyright Owner

The Authors

Language

en

File Format

application/pdf

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