1. Additive Manufacturing for X- band applications Alexej Grudiev 5/02/2014 CLIC14 workshop

2. 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

3. Additive manufacturing Process 1.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

4. Number of good reasons to try

5. Typical materials

6. 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

7. High power/E-field performance of Ti DC breakdown thresholds 30 GHz high power performance, PAC2007

8. 1.Low power prototype for material and fabrication characterization 1.DC conductivity and RF losses 2.UHV compatibility: leak tightness and outgassing 3.Shape accuracy and Roughness 4.Mechanical strength and Metallurgy 2.Prototypes for high power tests 1.Integration of cooling 2.High power performance 3.Design of the RF load 4.RF load prototype Three stages of the project We are here

9. Prototype Design  Prototype modelled in HFSS  WR90 end tapered to 13mm by 2mm middle 200mm

10. 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

11. 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

12. RF Results Comparison of S(1,1) parameter

13. RF Results Comparison of S(1,2) parameter

14. DC conductivity measurements Two 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

15. DC Results Waveguide No.Conductivity/ S/m 1 - EOS641025 2 - INP Grenoble368595 3 - Concept laser496771 4 - Concept laser500000 5 - Concept laser522739 Waveguide No.Conductivity [S/m] 1 - EOS716093 2 - INP Grenoble480179 3 - Concept laser571880 4 - Concept laser557176 5 - Concept laser580343 Method 1Method 2 a aqw 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

16. Determining parameters

18. 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-EOS64102512.9113.9>50-13.12 2-Grenoble36859512.7414.0>50-2.78 3-Concept49677112.7514.0>50-33.90 4-Concept50000012.7914.0>50-19.71 5-Concept52273912.8014.1>50-88.03 Waveguide No. DC cond. (S/m) (method 2) ‘a’ (mm)‘aqw’ (mm) HFSS roughness (µm) dB % difference at 12 GHz 1-EOS71609312.9014.0>50-20.29 2-Grenoble48017912.7414.0>50-15.56 3-Concept57188012.7414.0>50-40.02 4-Concept55717612.7914.0>50-25.79 5-Concept58034312.8014.1>50-95.53 HFSS Nominal: a=‘13mm’ aqw=‘14.2mm’ rough=‘0um’

19. Metrology Microtomography – X-ray non destructive testing Radioscopic image acquisition 1 2 3D reconstruction 3 Post processing Images: RX solutions gallery http://www.rxsolutions.fr/#!untitled/zoom/cjjm/i47og1

20. Metrology Results  Blue lines show lack of material  Red lines show excess material

22. 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-EOS641025 12.9113.9 >50-13.12 2-Grenoble368595 12.7414.0 >50-2.78 3-Concept496771 12.7514.0 >50-33.90 RF+DC measurements:

23. 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

24. Mechanical testing and metallographic observations Waveguide 2 Waveguide 3 Waveguide 1 Before etching After etching W1 shows least porosity W2 shows large porosity W3 shows different microstructure

25. Summary of the results obtained after tensile tests of the samples WG # CompanyE mod (GPa)Rp 0.2 (MPa)A %UTS (MPa) 1 3T112 ± 11097 ± 82 ± 01139.8 ± 3.0 2 IPN51 ± 0830 ± 3611 ± 2904.8 ± 20.4 3 Concept Laser108 ± 1825 ± 1112 ± 3893.4 ± 10.7 Table value for standard material (www.matweb.com) 120910 - 95812-16972 - 1030 OK

26. Summary Laser melting fabrication is validated for two manufacturers EBM fabrication requires some improvements Next step: