permanent magnets produced by cold spray additive ... · pdf filepermanent magnets produced by...
TRANSCRIPT
Magnetics 2017 Orlando January 19th 2017
Permanent Magnets Produced by Cold Spray Additive Manufacturing
Funded by: Vehicle Propulsion Technologies PERD - Natural Resources Canada
Jean-Michel Lamarre & Fabrice Bernier Research Officers
Proposed Approach: Cold Spray Additive Manufacturing
Advantages vs powder pressing : • Very good control of the microstructure (process vs feedstock) • Ease to modify geometry • Reduce costly machining steps • No assembly
vs Current magnets are... 1) Complicated to install (glue, screws,
grooves) → expensive to install and low design flexibility
2) Brittle and difficult to machine → low design flexibility
Proposed Approach: Cold Spray Additive Manufacturing
Key features: • High deposition rate (several kg per hour is possible) • Complex patterns are possible • Thicknesses from microns to centimeters
M-NdFeB
M: metal • Increase deposition efficiency • Good thermal conductivity • Corrosion/oxidation protection
NdFeB: hard magnetic phase • Strongest magnets • Provide coercivity and
saturation
Objectives
• Reduce rare earth quantity • Improve heat management • Allow new motor topologies by
increasing fabrication geometrical flexibility
• Reduce part number • Reduce fabrication steps
• Automate fabrication • Protect magnets from the
environment
DOE Vehicle Technologies Program
Objectives
Producing a low cost M-NdFeB composite permanent magnet using cold spray
5
Spray Parameters
Spray parameters: Plasma Giken 800 3 to 4.9 MPa 20 to 300 mm/s 400 to 800°C
Coating Adhesion/ cohesion: > 9000 psi Dense: negligible porosity. Thick: > millimeters deposited. Fv NdFeB: 30-65%
Magnetic powder: MQFP-B, 15 µm, irregular MQFP 14-12, 15 µm, irregular MQP-S-11-9, 25-75 µm, spherical Aluminum powder: Valimet 5 µm, 15 µm, spherical
6
On the Improvement of Magnetic Loading
Fall 2013 Base powder and parameters
Winter 2017 Improved metallic binder granulometry and improved process parameters
Spring 2015 Improved process parameters
Fall 2015 Optimized magnetic powder granulometry and optimized magnet/binder ratio
Magnetic Characterization
7
Powder type
Composition Size d50, μm
Morphology Br, mT Hc, kA/m
MQP-S-11-9
Nd-Pr-Fe-Co-TiZr-B
49.8 Spherical 745 710
MQFP-B Nd-Pr-Fe-B 10.2 Angular 880 752
MQFP-1412
Nd-Fe-Nb-B 10.7 Angular 817 961
H15 Aluminium 15 Spherical - -
Content of FeNdB: SEM image analysis to determine volume fraction of FeNdB in coating
Magnetic Characterization: Hysterisigraph Permagraph L from Magnet Physics Specimen: 10-25 mm diameter and 4 mm thickness, Provide: Br, Hc and BH
Effect of Powder Composition
8
0
50
100
150
200
250
300
-1000 -800 -600 -400 -200 0
Ind
uct
ion
B, m
TDemagnetization field H, kA/m
75%MQFP B + 25%Al-H15
75%MQFP 14-12 + 25%Al-H15
920 952
715 709
0100200300400500600700800900
1000
75% MQFP 14-12 - 25% Al
MQP 14-12powder
75% MQFP B -25% Al
MQFP Bpowder
Hc
(kA/
m)
0.25 0.28 0.276 0.29
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
75% MQFP14-12 - 25% Al
MQP 14-12powder
75% MQFP B -25% Al
MQFP Bpowder
Br (
T)
* *
Coercivity
Remanence
* Normalized to coating volume fraction.
The process does not significantly degrade the magnetic properties!
• Coating remanence is 5 to 10 % lower than the calculated value.
• Coating coercivity is 3 to 5% lower than the reference value.
Effect of Magnetic Loading Mélange Carrier gas (°C) Hc (kA/m) Br (T) Brcoating/Brdata Fv*
90%MQFP 14-12 - 10%Al H15
400 917 0.337 39.8 43.1
600 898 0.364 43.0 47.3 75%MQFP 14-12 - 25%Al H15
600 930 0.257 30.3 33.1
MQP 14-12 - Data 952 0.847 * Measured by image analysis
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
-1000 -800 -600 -400 -200 0
J (T
)
H (kA/m)
90% MQFP 14-12 - 600°C
75% MQFP 14-12 - 600°C
Increasing the NdFeB content in the starting mixes from 75% to 90% 1) Increases volumetric fraction and hence
remanence by 40%. 2) Does not significantly decreases Hc (3%).
Effect of Temperature Mélange Carrier gas (°C) Hc (kA/m) Br (T) Brcoating/Brdata Fv*
75%MQFP 14-12 - 25%Al H15
400 + cooling 937 0.233 27.5 28.5 500 930 0.238 28.1 30.7
600 920 0.25 29.5 33.5 600 + cooling 924 0.255 30.1 32.9
600 + cooling and wait 924 0.253 29.9 32.9
MQP 14-12 - Data 952 0.847 * Measured by image analysis
Confidential
Increasing gas temperature from 400°C to 600°C 1) Increases volumetric fraction and hence remanence by
10%. 2) Does not significantly decreases Hc (2%). 3) Cooling of substrate and waiting period between passes
had no significant effect.
0
50
100
150
200
250
300
350
400
-1000 -800 -600 -400 -200 0
Ind
uct
ion
B, m
T
Demagnetization field H, kA/m
400°C+Cooling 500°C
600°C 600°C+Cooling
600°C+Cooling+Wait
Effect of Temperature
0
0.1
0.2
0.3
0.4
0.5
-800 -600 -400 -200 0
Indu
ctio
n B
, T
Demagnetization field H, kA/m
1608111, 90 MQFP, 10 H5, 600C
1609192, 90 MQFP, 10 H5, 800C
1609201, 90 MQFP, 10 H5, 700C
Increasing gas temperature from 600°C to 700°C Does not alter the magnetic content hence magnetic properties are unchanged.
Increasing gas temperature from 700°C to 800°C Does not alter the magnetic content but magnetic properties are slightly decreased.
Demagnetization Temperature
Coating: 90%MQFP-B - 10%Al H5
Powder datasheet
0
0.1
0.2
0.3
0.4
0.5
-800 -600 -400 -200 0
Indu
ctio
n B
, T
Demagnetization field H, kA/m
25°C 50°C
75°C 100°C
125°C 150°C
175°C 200°C
0 100 200 300 4000.20
0.22
0.24
0.26
0.28
Diff
usiv
ity (c
m2 /s
)
Temperature (oC)
Others Characterization Techniques
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
-800 -700 -600 -500 -400 -300 -200 -100 0
J (T
)
H (kA/m)
Original
300°C - 100h
500°C - 15 min
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
-900 -800 -700 -600 -500 -400 -300 -200 -100 0
J (T
)
H (kA/m)
Original
300°C - 100h
500°C - 15 min
Aging: Effect of aging treatment on magnetic performance for a) MQP-S-11-9 and b) MQFP-14-12 NdFeB powder.
Protective layer: SEM image showing a 2 layer-structure. Bottom layer is a composite NdFeB-Al while top layer is Al.
Laser flash diffusivity: 75% MQFP, 25% aluminium powder
Demonstrator Magnetization Testing
Validate magnetization and performance of an industrial component
Demonstrate machinability
Magnetization and measurement by Magnet-Physics
-100
-80
-60
-40
-20
0
20
40
60
80
100
0 50 100 150 200 250 300 350 400
B r
ad [
mT]
Rotational angle [°]
B radial - distance 1 mm from surface
Upper Line
Middle Line
Lower Line
-80
-60
-40
-20
0
20
40
60
80
0 50 100 150 200 250 300 350 400
B r
ad [
mT]
Rotational angle [°]
B radial - distance 3 mm from surface
Upper Line
Middle Line
Lower Line
Magnetic mapping for 90% NdFeB
magnet on steel
Magnetic mapping for 90% NdFeB
magnet on aluminium
15
Outer Diameter
Key objectives: • Deposit thick and wide
magnet.
• Optimize spray parameters for fast deposition.
• Evaluate time and cost.
Outer diameter prototype with four strips design, diameter ≈ 17 cm
16
Complex Inner Diameter
Key objective: • Use complex robot programming
to achieve complex design on inner diameter.
• Develop ability to spray at an angle with high deposition efficiency
• Adapt the spray geometry (gun size, spray distance and angle) to an inner diameter
17
Vertical Walls
Key objectives: • Optimize robot programming and
process parameters to achieve vertical walls.
Cross-section optimization
Conclusions
• High density coating with high NdFeB content. Magnetic properties follow mixture law.
• High deposition efficiency. • Increase heat diffusivity.
• Interface adhesion exceeding industrial standard (> 65 MPa).
• Environmental sealing via appropriate top-coat use.
• Improved high temperature resistance.
250°C – 10h
Conclusions
1) Assembled rare earth permanent magnets were fabricated by cold spray 2) Complex shape rotor can be readily fabricated without assembly
Technology Development 2017-2020
Next steps • Integrate coating permanent
magnet technology to actual motor design.
• Explore design possibilities offered by the added manufacturing flexibility.
Project Team
Automotive and Surface Transportation Portfolio - Thermal Spray and Powder Forming groups. • Jean-Michel Lamarre, Project leader. • Fabrice Bernier, Task leader characterization. • Thermal spray: J.-F. Alarie, F. Belval, J. Sykes, J.-C.
Tremblay. • Characterization: S. Mercier, D. de Lagrave, D. Simard,
K. Théberge. • Robot toolpath programming: M. Martin.
22
Questions?
Acknowledgment
The authors gratefully acknowledge financial support for this
project from Natural Resources Canada through its Energy
Research and Development Program and the National
Research Council through its Vehicle Propulsion
Technologies Program
23
Thank you Jean-Michel Lamarre Research Officer Tel: 450-641-5386 [email protected] www.nrc-cnrc.gc.ca
24