additive manufacturing for x- band applications alexej grudiev 5/02/2014 clic14 workshop
TRANSCRIPT
Additive Manufacturing for X-band applications
Alexej Grudiev5/02/2014
CLIC14 workshop
Acknowledgements• BE-RF• Miriam Colling• Alexej Grudiev
• EN-MME• Said Atieh • Ofelia Capatina• Floriane Leaux• Raphael Leuxe• Thomas Sahner• Ignacio Santillana
• TE-VSC• Sergio Calatroni• Ivo Wevers
Additive manufacturingProcess1. Model designed in CAD
2. CAD file sent to additive manufacturing system
3. Model divided into slices
4. 3D product sculpted from powdered material layer by layer using the specified technique
EOS – SLS, http://www.eos.info/additive_manufacturing/for_technology_interested
Number of good reasons to try
Typical materials
Technical data Ti64
Ti64 DC electrical conductivity: 600000 S/m, two times lower than stainless steel
• Relatively low accuracy• Big roughness (much larger than skin depth)• Low DC conductivity
Obvious RF application is a broad-band all-metal dry RF load
High power/E-field performance of TiDC breakdown thresholds 30 GHz high power performance, PAC2007
1. Low power prototype for material and fabrication characterization
1. DC conductivity and RF losses2. UHV compatibility: leak tightness and outgassing3. Shape accuracy and Roughness 4. Mechanical strength and Metallurgy
2. Prototypes for high power tests1. Integration of cooling2. High power performance
3. Design of the RF load4. RF load prototype
Three stages of the project
We are here
Prototype Design Prototype modelled in HFSS
WR90 end tapered to 13mm by 2mm middle
200mm
5
Waveguide manufacturing methods
Waveguide 1:EOS – Selective laser sintering
Waveguide 2:Grenoble INP – Electron beam melting
Waveguides 3, 4 and 5:Concept – Selective laser melting
Length: 20cm Material: Titanium alloy
RF measurements using VNA
• Obtained data for S(1,1), S(1,2), S(2,1) and S(2,2) parameters for each of the five waveguides
• Measurements required careful handling - movement in cables cause readings to change
• Measurements repeated three times for each waveguide for reliable results
RF Results
11.4 11.6 11.8 12 12.2 12.4 12.6-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
HFSS simulation
Waveguide 1
Waveguide 2
Waveguide 3
Waveguide 4
Waveguide 5
Frequency/GHz
S(1,
1)/d
B
Comparison of S(1,1) parameter
11.4 11.6 11.8 12 12.2 12.4 12.6-35
-30
-25
-20
-15
-10
-5
0
HFSS simulation
Waveguide 1
Waveguide 2
Waveguide 3
Waveguide 4
Waveguide 5
Frequency/GHz
S(1,
2)/d
BRF Results
Comparison of S(1,2) parameter
DC conductivity measurementsTwo types of DC measurements:1. Four probes in contact with middle section
2. Two probes in contact with middle while clamps on flange provide voltage difference
6mm
62mm
Titanium alloy conductivity: 6E+5 S/m
DC Results
Waveguide No. Conductivity/ S/m
1 - EOS 641025
2 - INP Grenoble 368595
3 - Concept laser 496771
4 - Concept laser 500000
5 - Concept laser 522739
Waveguide No. Conductivity [S/m]
1 - EOS 716093
2 - INP Grenoble 480179
3 - Concept laser 571880
4 - Concept laser 557176
5 - Concept laser 580343
Method 1 Method 2
aaqw
Apply all DC cond. to HFSS waveguide and obtain values for
all 3 parameters in each case
Nominal HFSS values:‘aqw’=14.2mm ‘a’=13mm Roughness=0µm
Titanium alloy conductivity: 6E+5 S/m
Determining parameters
11.4 11.6 11.8 12 12.2 12.4 12.6-35
-30
-25
-20
-15
-10
-5
0
Determining 'aqw' of waveguide 1 (cond=641025 S/m)
HFSS Nominal: aqw='14.2mm'
Measured: Waveguide 1
Matched: aqw='13.9mm'
Frequency/GHz
S(1,
1)/d
B
Determining parameters
11.4 11.6 11.8 12 12.2 12.4 12.6-25
-20
-15
-10
-5
0
Determining 'a' and roughness of waveguide 1 (cond=641025 S/m)
HFSS Nominal: a='13mm' aqw='14.2mm' rough='0um'
Measured: Waveguide 1
Matched: a='12.91mm' aqw='13.9mm' rough='50um'
Frequency/GHz
S(1,
2)/d
B
Table of parameters
Tables show:• Values for each modified parameter: ‘a’ , ‘aqw’ and HFSS roughness
• 100-300 micron differences • Change in parameters required to provide HFSS results which agree with
those produced by the VNA for each waveguide
Waveguide No. DC cond. (S/m) (method 1)
‘a’ (mm) ‘aqw’ (mm) HFSS roughness (µm)
dB % difference at 12 GHz
1-EOS 641025 12.91 13.9 >50 -13.122-Grenoble 368595 12.74 14.0 >50 -2.783-Concept 496771 12.75 14.0 >50 -33.904-Concept 500000 12.79 14.0 >50 -19.715-Concept 522739 12.80 14.1 >50 -88.03
Waveguide No. DC cond. (S/m) (method 2)
‘a’ (mm) ‘aqw’ (mm) HFSS roughness (µm)
dB % difference at 12 GHz
1-EOS 716093 12.90 14.0 >50 -20.29
2-Grenoble 480179 12.74 14.0 >50 -15.56
3-Concept 571880 12.74 14.0 >50 -40.02
4-Concept 557176 12.79 14.0 >50 -25.79
5-Concept 580343 12.80 14.1 >50 -95.53
HFSS Nominal: a=‘13mm’ aqw=‘14.2mm’ rough=‘0um’
MetrologyMicrotomography – X-ray non destructive testing
Radioscopic image acquisition 1
2 3D reconstruction
3Post processing
Images: RX solutions gallery http://www.rxsolutions.fr/#!untitled/zoom/cjjm/i47og1
Metrology Results Blue lines show lack of material Red lines show excess material
Metrology Results First three waveguides were measured using microtomography to determine dimensions ‘a’ and
‘aqw’
Measured ‘a’ at 3 points and ‘aqw’ and 2 points and an average was found
Waveguide 1 and 3 < 100micron difference from nominal
Waveguide No. DC cond. (S/m) (method 1)
‘a’ (mm) ‘aqw’ (mm) HFSS roughness (µm)
dB % difference at 12 GHz
1-EOS 641025 12.91 13.9 >50 -13.122-Grenoble 368595 12.74 14.0 >50 -2.783-Concept 496771 12.75 14.0 >50 -33.90
RF+DC measurements:
Vacuum
Waveguide 1, 3,4 and 5 are leak tight, OK for UHV
Waveguide 2 was not be able to pump down due to presence of small holes
Mechanical testing and metallographic observations
Waveguide 2 Waveguide 3Waveguide 1
Befo
re e
tchi
ngAft
er e
tchi
ng
W1 shows least porosity W2 shows large porosity W3 shows different microstructure
Summary of the results obtained after tensile tests of the samples
WG # Company Emod (GPa) Rp0.2 (MPa) A % UTS (MPa)
1 3T 112 ± 1 1097 ± 8 2 ± 0 1139.8 ± 3.0
2 IPN 51 ± 0 830 ± 36 11 ± 2 904.8 ± 20.4
3 Concept Laser 108 ± 1 825 ± 11 12 ± 3 893.4 ± 10.7
Table value for standard material (www.matweb.com)
120 910 - 958 12-16 972 - 1030
OK
OK
Summary• Laser melting fabrication is validated for two
manufacturers• EBM fabrication requires some improvements• Next step: