Thomas A Berfield

Dr. Thomas A Berfield

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2021 in Journal of Sound and Vibration
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Journal Article
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MDMasoud Derakhshani
Masoud Derakhshani
NMNiknam Momenzadeh
Niknam Momenzadeh
TBThomas A Berfield
Thomas A Berfield

1 January 2016 in Thin Solid Films
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Journal Article
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TBThomas A Berfield
Thomas A Berfield
RKRajesh Kitey
Rajesh Kitey
SKSoma S. Kandula
Soma S. Kandula

15 December 2009 in Journal of Applied Physics
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Journal Article
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TBThomas A Berfield
Thomas A Berfield
JCJ. F. Carroll
J. F. Carroll
DPD. A. Payne
D. A. Payne
NSN. R. Sottos
N. R. Sottos
A fluorescence-based digital image correlation (DIC) technique is used to characterize the in-plane strain development of blanket sol-gel derived lead zirconate titanate thin films deposited on platinized silicon substrates. The in-plane strain is also measured within film line features patterned via a mediated octadecyltrichlorosilane (ODS) monolayer. The results indicate that the selective film failure induced by the mediated ODS layer succeeds in slightly reducing the in-plane strain transverse to the line feature direction (∼25% lower), while remaining nearly the same as the blanket film case in the direction parallel to the line direction. Additional in-plane stress estimates from wafer curvature measurements for the two film configurations (blanket and ODS patterned) were consistent with the DIC measured strain results.

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SNSuyash Niraula
Suyash Niraula
BDBrendon Dodge
Brendon Dodge
JGJustin D. Gillham
Justin D. Gillham
TBThomas A Berfield
Thomas A Berfield
Creating complex structures using multiple materials in additive manufacturing comes with a unique set of challenges, particularly when it comes to how the materials transition and bond together. This research looks at a new powder binning method for combining metal powders to create multi-material components in a single build, all produced on a standard Laser Powder Bed Fusion EOS M 290 machine. The study focuses on the size and quality of the resulting multi-material interfaces and how different scan strategies used affect the interface strength. The strength of the interface between different material pairings is evaluated for combinations of 316 stainless steel bonded to Inconel 718, Inconel 718 bonded to Inconel 625, and Inconel 625 bonded to 316 stainless steel. The Ultimate Tensile Strength (UTS) and interface region lengths were calculated to be 675 MPa and 1250 µm for 316L–IN718, 1004 MPa and 2500 µm for IN718–IN625, and 687 MPa and 2000 µm for IN625–316L, respectively. The findings show that the laser powder bed fusion material binning method is comparable to traditional methods, such as welding or directed energy deposition. This suggests that the new material binning method offers clear advantages when it comes to enabling complex geometry multi-material components while maintaining the strength and durability of the bonds between different metal materials found in traditional means. Further, optimization of scan strategies in the interface zones could play a significant role in improving the overall performance of these multi-material components, which is particularly important for industries such as aerospace, automotive, and energy production.

10 June 2025 in Materials Letters
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Journal Article
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NDNicholas Derimow
Nicholas Derimow
TBThomas A Berfield
Thomas A Berfield
KHKeenan Hanson
Keenan Hanson
JBJake T. Benzing
Jake T. Benzing
NHNik Hrabe
Nik Hrabe

16 July 2026 in Powders
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BDBrendon Dodge
Brendon Dodge
SNSuyash Niraula
Suyash Niraula
NSNaiyer Shokri
Naiyer Shokri
JGJustin D. Gillham
Justin D. Gillham
TBThomas A Berfield
Thomas A Berfield
Growing attention in additive manufacturing (AM) of high-entropy alloys has intensified the demand for techniques in creating high-quality powder for AM. This study characterizes the effectiveness of a multifunctional vacuum arc melting (VAM) and ultrasonic-plasma atomization (UPA) system for creating TiZrNbHfTa powder. The focus is to evaluate the morphology, microstructural homogeneity, and phase composition of ultrasonically atomized powder to assess process capability for preparing powder feedstock for AM. Atomized powder was sieved into three size ranges, 15–63 µm, 63–125 µm, and 125–250 µm for characterization by scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and micro-computed tomography (micro-CT). SEM, EDS, and XRD results show that the powder is highly homogenous with an elemental distribution independent of powder size range and a microstructure comprising a BCC solid solution and minor monoclinic Ti oxide. Micro-CT scans indicate low porosity (0.24%, 0.08%, 0.24%) and high sphericity (0.93, 0.90, 0.93) for the 15–63 µm, 63–125 µm, and 125–250 µm distributions, respectively. Overall, the key innovation of this study is the successful application of ultrasonic atomization to produce high-quality TiZrNbHfTa refractory high-entropy alloy powder for additive manufacturing, a technique that has a limited scope of research. Specifically, this work demonstrates that ultrasonic atomization can produce highly homogeneous powder with high sphericity, low porosity, and a particle size distribution suitable for laser powder bed fusion and powder directed energy deposition, establishing ultrasonic atomization as a viable route for producing refractory high-entropy alloy powder for AM.