Presentation given at a local MRS Chapter meeting on Rare Earth Technology; April 2011.

1. ETREMA Products, Inc.
Giant Magnetostrictive
Material Technologies
Symposium on Rare Earth Materials
Iowa State University
Eric Summers, ETREMA Products

2. ETREMA Products, Inc.
Outline
Intro to ETREMA Products
Terfenol-D Technology
Terfenol-D Applications
Impact of Rare Earth Environment on T-D
Galfenol Technology – non REE Substitute
Permanent Magnets
Summary & Conclusions
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

3. ETREMA Products, Inc.
ETREMA Products, Inc.
Primary business: smart material sales, smart
material enabled devices, and engineering services
based on magnetostriction
• Small business – Ames, IA
• Started in 1987 as a foundry for
Terfenol-D
• Developed engineering capability
in early 90’s to grow the market
• World leader in products and
systems based on magnetostrictive
technology
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

4. ETREMA Products, Inc.
Products & Applications
Low frequency Mid frequency High frequency
applications applications applications
(DC – 200 Hz) (200 Hz – 10 kHz) (10 kHz – 30 kHz)
Standard actuator line Ultrasonic CU18
AMS active
machining
systems
Integrated systems
(transducer, amplifier,
radio)
Oil & Gas Tools
SONAR transducers
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

5. ETREMA Products, Inc.
Magnetostriction
• Magnetostriction converts electrical energy into mechanical
energy and vice versa
• Anisotropic property – crystal orientation dependence
• Change in shape is completely elastic - no fatigue
Magnetostriction is a reversible effect
Actuator - Joule Effect
Magnetic Mechanical
Field Strain
Sensor – Villari Effect
“energy harvesting”
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

6. ETREMA Products, Inc.
Giant Magnetostriction
Discovered in the 1960’s for heavy rare earth metals
– Legvold, Clark, and Rhyne
At cryo temps or lower, ~1% strain, Tb & Dy
1970’s search for room temperature giant
magnetostrictive alloys
RE-Ni, RE-Co, RE-Fe alloys investigated
TbFe2 and SmFe2; (+2000 ppm, -2000 ppm at RT)
Magnetic anisotropy still very large
Work completed at Ames Lab and Naval Ordnance
Labs (NOL)
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

7. ETREMA Products, Inc.
Terfenol-D
Terfenol-D is an intermetallic compound:
Terbium Tb
Dysprosium Dy
Iron Fe
Nominal composition is Tb0.3Dy0.7Fe1.92
Tb:Dy ratio tailored to fit application
Tb generates the majority of the magnetostriction
Dy reduces magnetic anisotropy
Fe stabilizes magnetic ordering to ambient
temperatures (raises Tc)
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

8. Terfenol-D Microstructure
ETREMA Products, Inc. Dy – Fe Phase Diagram
RFe2
Eutectic
Fe2Dy
Fe3Dy
• R (Tb, Dy) Fe2 dendrites aligned parallel
• Eutectic phase (Tb, Dy) sets spacing
between dendrites
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

9. ETREMA Products, Inc.
• Excessive (Tb, Dy) losses can lead
to RFe3 phase and/or Widmanstatten
precipitates
• Symmetry disruption and domain
wall pinning
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

10. ETREMA Products, Inc.
Terfenol-D Mfg. Techniques
Method Advantage Disadvantage
Bridgman (ECG) Production method Smallest diameter - 10mm
Low cost, Diameters up
to 65mm diameter
FSZM Highest strain Largest diameter - 9mm
Full <112> orientation Research method
Highest Cost
Powder Metallurgy Near Net Shape Performance issues
Production method for
small pieces
Terfenol-D ECG located at
ETREMA
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

11. Magnetostriction in
Terfenol-D
ETREMA Products, Inc.
1600
1400
1200
Magnetostriction (ppm)
1000
800
FSZM
ECG
600
400
200
0
-2000 -1500 -1000 -500 0 500 1000 1500 2000
Applied Field (Oe)
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

12. ETREMA Products, Inc.
AMS Technology
Enables production of tight
tolerance, non-round
components
• Target market – small engine
pistons
• Readily adapted to standard
CNC lathes
• Spindle speed up to 6000
RPM
• 1 piston every 10 seconds
• Multiple systems in
AMS actuator integrated onto a
production – first system
conventional lathe
online in 2001
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

13. ETREMA Products, Inc.
Actuator Video
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

14. ETREMA Products, Inc.
AMS Details
AMS is a T-D actuator working in
a micro-positioning application
Robust nature, positioning speed
(bandwidth), and accuracy
(repeatability) are what make AMS
unique.
We move the actuator 5000 times
every second and hold it to within
1 micron of desired position.
Compensating for the natural
ferromagnetic hysteresis in the T-
D was the major technological
leap that occurred during AMS
development.
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

15. ETREMA Products, Inc.
CU18A Ultrasonic Actuator
15-20 kHz horn bandwidth
Maximum output power at 18
kHz
Peak output displacement = 10
microns
High dynamic force = 3250 N
Magnetic flux leakage free
• Dimensions: 2” dia. X 5.2” length
• Multiple mounting options and horn
configurations
• Active cooling option
• www.etrema.com
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

16. ETREMA Products, Inc.
CU18A + Horn
CU18 with 20.5 kHz horn attached
Applications
Ultrasonic source
Micro positioning
Sono-Chemistry
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

17. ETREMA Products, Inc.
Sono-Chemistry
High intensity acoustic fields
create cavitation
Cavitation bubbles are
essentially micro scale
combustion chambers
reaching temperatures of
9,000 °F
Extremely high mechanical
forces:
15,000 psi
250 mph jet streams
Particle dispersion,
emulsification, degassing
Photos by K.S. Suslick, University of Illinois.
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

18. ETREMA Products, Inc.
Cavitation
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

19. ETREMA Products, Inc.
Navy Sonar Transducers
• Terfenol-D was invented by the
U.S. Navy for its next
generation sonar systems
• SEA TALON is a program with
Lockheed-Martin for an active
source towed by an unmanned
underwater vehicle
• Multiple other programs
• Either performance data is
classified, designs are
proprietary, or NDA’s exist
between parties
Sea Talon Program
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

20. ETREMA Products, Inc.
Small Synthetic Aperture Sonar*
Work done out of NSWC – Panama City with Penn
State ARL and Woods Hole Oceanographic Inst.
Terfenol-D is utilized as one of the active sources
High resolution imagery at low frequencies – Small
Synthetic Aperture Minehunter (SSAM)
SSAM is a dual frequency band system; high and
low frequency bands
Imaging resolutions at high frequency: 1 in x 1 in
Imaging resolutions at low frequency: 3 in x 3 in
Detect and classify proud and shallow buried targets
located on ocean floor
* Daniel Brown, Daniel Cook, Jose Fernandez, Naval Surface Warfare Center - Panama City, Code HS11, 110
Vernon Avenue, Panama City, FL 32407-7001
* Proceedings of the MTS/IEEE OCEANS 2006 Boston Conference and Exhibition
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

21. ETREMA Products, Inc. SSAM on REMUS 600 AUV
- Image taken from Woods Hole
Oceanographic Institute website
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

22. ETREMA Products, Inc.
- Image taken from Woods Hole Oceanographic - Image taken from Proceedings of the MTS/IEEE
Institute website OCEANS 2006 Boston Conference and Exhibition
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

23. Impact of Current Rare Earth
ETREMA Products, Inc.
Environment on Applications
Terfenol-D is an alloy of Heavy Rare Earth Elements
(HREE’s)
60% Terbium (Tb) and Dysprosium (Dy) by weight
High purity metals required
Sublimed quality Tb and Dy not distilled
Tb and Dy sublimed metal supply currently available
High value product for Chinese market
Pricing increased dramatically over last 1-2 years
Increases impacting at alloy level not yet significant at
device or system level
Alternative sources and substitutes under investigation
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

24. Galfenol
ETREMA Products, Inc.
a REE Technology Substitute
• Discovered in 1999-2000 by: Clark et al., NSWC, Ames Lab (Lograsso et. al)
Fe-Ga: 200 – 400 ppm, structural
Ni: 50 ppm Terfenol-D: 1000 ppm
Low Magnetostriction High Magnetostriction
Structural (strong) Brittle
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

25. ETREMA Products, Inc.
Projected Supply Risk
Supply of Terbium and Dysprosium potentially
a problem in the foreseeable future
Gallium does not have the same supply risk
Figures copied from US Dept. of Energy, “Critical Materials Strategy – December 2010”, p. 8
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

26. Magnetostriction vs.
ETREMA Products, Inc.
Composition (single crystal)
450
400
Fe100-xGax
H = 15 kOe
Fe1-xGa(0.15 ≤ x ≤ 0.20)
350
3/2 λ100 (x 10-6)
300 • All single crystal data taken from
Magnetic Materials Group –
250 Carderock Division, Naval Surface
Warfare Center (NSWC)
200
• Etrema’s efforts have focused on
150 the first magnetostrictive peak
between 15 at% Ga and 20 at% Ga
100 • Nominal Ga content in Etrema
Furnace Cooled
50 Quenched produced Galfenol is 18.4 at%
Directionally Solidified (Unannealed)
Quenched in Brine • Etrema produces polycrystalline
0 Furnace Cooled, Multi-phase samples
0 5 10 15 20 25 30 35 40
x
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

27. Galfenol – Terfenol-D
Comparison
ETREMA Products, Inc.
Galfenol vs. Terfenol-D
1200
Galfenol - 18.4R - 7ksi
Magnetostrictive Response, ppm
1000
FSZM T-D - 2ksi
800
600
400
200
0
0 200 400 600 800 1000
Magnetic Field, Oe
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

28. Galfenol – Terfenol-D
ETREMA Products, Inc.
Comparison
Galfenol vs Terfenol-D
16000
14000
Magnetic Flux Density, B, Gauss
12000
10000
8000
6000
4000
Galfenol, FSZM18.4-R, 5ksi
2000
Terfenol-D, FSZM, 1ksi
0
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Magnetic Field, Oe
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

29. ETREMA Products, Inc.
Galfenol Processing Methods
Galfenol nano-wires produced by
Dr. Beth Stadler’s group, U. of
Minnesota
Oriented Sheet
2.5 inches
RD
(110)<100>
10 inches
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

30. Galfenol Components
ETREMA Products, Inc.
Laminated and machined threads
Forged and machined shapes
Laminated and milled stack
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

31. ETREMA Products, Inc.
Galfenol for Micro Devices
Images and video courtesy of Dr.
Toshiyuki Ueno, Kanazawa U., Japan
Galfenol produced by ETREMA
Illustrates Galfenol micro-components
can be fabricated using conventional
machining techniques
Micro-milling of Galfenol laminate
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

32. ETREMA Products, Inc.
Micro Spherical Motor
Device courtesy of Dr. Ueno,
Kanazawa U.
Galfenol supplied by ETREMA
Multi-DOF in 1 motor
• 1 kHz, 0.2 A
• Angel range = 360°
• Angle velocity = 50°/sec
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

33. Role of Permanent Magnets in
ETREMA Products, Inc.
Magnetostrictive Technologies
Magnetic biasing via PM’s:
NdFeB or SmCo used, high
strength (grade 38+ for
Neo’s, typical)
Necessary to prevent
frequency doubling and
operate in a “linear” region
DC biasing effective but
inefficient
Stable supply of PM’s
critical for future
magnetostrictive Optimum bias point for a piece of Galfenol
technologies (Terfenol-D or
Galfenol)
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University

34. ETREMA Products, Inc.
Summary & Future Direction
Terfenol-D is a mature technology integrated
into multiple fields-of-use
Applications development is dynamic
High HREE content poses short- and mid-
term risks
Galfenol is a non-REE substitute under
development
Galfenol technology is transitioning into the
Applications stage
Symposium on Rare Earth Materials
April 7, 2011 Iowa State University