Structure and Properties of Titanium Tantalum Alloys for Biocompatibility Dissertation Presented in

143 Pages·2016·5.25 MB·English

by  Daniel Huber

Structure and Properties of Titanium Tantalum Alloys for Biocompatibility

Dissertation

Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy
in the Graduate School of The Ohio State University

By
Daniel E. Huber
Graduate Program in Materials Science and Engineering

The Ohio State University
2016

Committee:
Dr. Hamish L. Fraser, Advisor
Dr. David McComb
Dr. Stephen Niezgoda
Copyrighted by
Daniel E. Huber
2016
Abstract

In this thesis, the phase stability and elastic modulus of Ti–Ta simple binary
alloys as well as alloys with small additions of ternary elements have been studied. The
binary alloy from a nominal 8 to 28 wt.% Ta was first explored using a combinatorial
approach. This approach included Laser Engineered Net Shape (LENS™) processing of
materials and subsequent characterization by instrumented indentation and site specific
Transmission Electron Microscopy (TEM). The composition range of 15 to 75 wt.% Ta
was further explored by more traditional methods that included vacuum arc melting high
purity elements, X-Ray Diffraction (XRD) and modulus measurements made by
ultrasonic methods. Beyond the simple binary, alloys with low levels of ternary
elements, oxygen, aluminum, zirconium and small additions of rare earth oxides were
investigated.
The crystal structure with space group Cmcm was chosen for it applicability with
P6 /mmc and !"3! sub group / super group symmetry. This provides a consistent
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crystal structure framework for the purpose of studying the α to β transformation pathway
and associated α’ and α’’ martensitic phases. In this case, the pathway is defined by both
the lattice parameters and the value of the parameter “y”, where the parameter “y”
describes the atomic positions of the [002] plane. It was found that the lattice
α’’
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parameter changes in the Ti–Ta binary alloys are similar to structures reported for
compositions in the Ti–Nb system of similar atomic percentages.
Although samples produced by the LENS™ process and characterized by
instrumented indentation demonstrated the correct trends in modulus behavior, absolute
agreement was not seen with modulus values published in literature. Alloys of the binary
Ti–Ta system produced from high purity materials do indeed show close agreement with
literature where there exist two minima of modulus near the compositions of Ti–28Ta
wt.% and Ti–68Ta wt.%. These two minima occur at the discreet boundary between α’ /
α’’ and α’’/ β respectively.
The role of oxygen as an alloying addition was studied as it relates to the stability
of α’ and α’’ martensite, here it was found that oxygen will stabilize α’ yet cause an
increase in the Young’s modulus. Rare earth additions to getter interstitial oxygen in the
high purity materials show no further reduction in modulus. Conversely, additions of
another α stabilizer, Al, proved to lower the α’ stability, with one composition exhibiting
a modulus as low as 53 GPa. Zirconium being a neutral element regarding α and β
stability slightly changed the structure and lattice parameter, while making a little or no
difference in the observed modulus.
Observations by TEM of quenched specimens indicate the rise in modulus
observed between the two minima is not caused the appearance of ω. Rather weak ω
reflections were observed in Ti–65Ta wt.% in the as arc-melted condition and on
annealing for 450°C for 24 hours. Precipitates of ω were not clearly identified by dark-
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field TEM imaging. High Resolution Scanning Transmission Electron Microscopy
(HRSTEM) of the aged specimen indicated that ω might exist as 3-5nm particles.

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Dedication
This document is dedicated to my family and especially my younger brother Dennis.

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Acknowledgments

I would like to sincerely thank my advisor Dr. Hamish L. Fraser for his encouragement,
patience and tireless support of my academic efforts. I would also like to thank all the
members of the Fraser research group past and present for their support and mentorship.

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Vita

June 1996 ....................................................... Centerville High School
June 2003 ....................................................... B.S. Materials Science and Engineering,
Ohio State University
June 2007 ....................................................... M.S. Materials Science and Engineering,
Ohio State University
June 2007 to June 2013 ................................ Research Engineer, Department of Materials
Science, The Ohio State University
June 2013 to present ..................................... Lead Instrumentation Scientist, Center for
Electron Microscopy and Analysis, The
Ohio State University

Publications

J.K. Jensen, B.A. Welk, R.E.A. Williams, J.M. Sosa, D.E. Huber, O.N. Senkov, G.B.
Viswanathan, H.L. Fraser: Characterization of the microstructure of the compositionally
complex alloy Al1Mo0.5Nb1Ta0.5Ti1Zr1.
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J. M. Sosa, J. K. Jensen, D. E. Huber, M. A. Gibson, H. L. Fraser: Three-dimensional
characterization of microstructure of high entropy alloy using STEM/HAADF
tomography. Materials Science and Technology 04/2015; 31(10).
DOI:10.1179/1743284715Y.0000000049

Y. Liu, P. Samimi, I. Ghamarian, D. A. Brice, D. E. Huber, Z. Wang, V. Dixit, S. Koduri,
H. L. Fraser, P. C. Collins: Discovery via Integration of Experimentation and Modeling:
Three Examples for Titanium Alloys. JOM: the journal of the Minerals, Metals &
Materials Society 12/2014; 67(1). DOI:10.1007/s11837-014-1197-3

R. E. A Williams, D. Huber, J. Sosa, H. L. Fraser: 15 Years of Characterizing Titanium
Alloys' Microstructure by DBFIB. Microscopy and Microanalysis 08/2014; 20(S3).
DOI:10.1017/S143192761400333X

J.M. Sosa, D.E. Huber, B. Welk, J.K. Jensen, R.E.A. Williams, S. Lambert, H.L. Fraser:
3D ChemiSTEM™ Tomography of Nano-scale Precipitates in High Entropy Alloys.
Microscopy and Microanalysis 08/2014; 20(S3). DOI:10.1017/S1431927614005546

Binbin Deng, Camila M. Freria, Robert E.A. Williams, Daniel Huber, John Sosa, Philip
G. Popovich, David W. McComb: 3D Visualization of Motor-Neurons in Mice Spinal
Cord Using FIB\SEM Tomography. Microscopy and Microanalysis 08/2014; 20(S3).
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DOI:10.1017/S1431927614008733

John M Sosa, Daniel E Huber, Brian Welk, Hamish L Fraser: Development and
application of MIPAR: A novel software package for two- and three-dimensional
microstructural characterization. 04/2014; 3(1). DOI:10.1186/2193-9772-3-10

R. A. Causey, D. F. Cowgill, R. Doerner, R. Kolasinski, B. Mills, D. Morse, J.
Smugeresky, W. R. Wampler, R. Williams, D. Huber: Deuterium retention in tungsten at
elevated temperatures. Journal of Nuclear Materials 08/2011; 415(1).
DOI:10.1016/j.jnucmat.2010.10.057

D Huber, H L Fraser, D O Klenov, H S Von Harrach, N J Zaluzec: Relative Sensitivity of
XEDS vs EELS in the AEM.

HO Colijn, DE Huber, PC Collins, HL Fraser: Practical Remote Microscopy Using KVM
over IP. Microscopy and Microanalysis 07/2010; 16. DOI:10.1017/S1431927610057843

A. Blankemeier, D. E. Huber, H. L. Fraser, W. Goodson, Rea Williams, H. O. Colijn:
Characterization of Pseudomonas Fluorescens Bacteria on Polyurethane Using DB-FIB,
SEM and STEM. Microscopy and Microanalysis 07/2010; 16(S2).
DOI:10.1017/S1431927610062045

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