rfbpm windows joining effort undulator system
DESCRIPTION
RFBPM Windows Joining Effort Undulator System. W. Toter, D. Bromberek, F. Depaola, L. Morrison, R. Lill, W. Berg, G. Pile, L. Erwin, J. Chen, C. Ferrari, J Bailey, D. Walters. Single Piece Transitions. Order of Joining. K1. Strongest Design. Order of Joining. K2. - PowerPoint PPT PresentationTRANSCRIPT
Jan. 22-23, 2008LCLS Undulator Week
1 Dean R. Walters
RFBPM Windows Joining EffortUndulator System
W. Toter, D. Bromberek, F. Depaola, L. Morrison, R. Lill, W. Berg, G. Pile, L.
Erwin, J. Chen, C. Ferrari, J Bailey, D. Walters
Jan. 22-23, 2008LCLS Undulator Week
2 Dean R. Walters
RFBPM Window-Transition AssemblyUnacceptable Yield
Problem: Broken and Leaking Windows
Designs
Joining
1. A successful joining process will be used to determine which design to select
2. Secondarily, joining methods that cannot be made to work will exclude a design.
Jan. 22-23, 2008LCLS Undulator Week
3 Dean R. Walters
K1 K2
Au-GeAu-Sn
Au-GE
Au-SnH2
Sn-Ag-Cu
K1
K2
Order of Joining
Order of Joining
Single Piece Transitions
K2 K1
Au-CuAu-Ge
Au-Sn
Au-GeAu-SnH2
Sn-Ag-Cu
Au-Sn H2
Sn-Ag-Cu
This allows windows to be jointed, tested, and selected before joining
to the cavity body.
Strongest Design
Jan. 22-23, 2008LCLS Undulator Week
4 Dean R. Walters
Designs
Designs
CPI Window-Transition Assembly
1 joint
1 Piece Transition2 Joints
2 Piece Transition3 Joints
2nd AlternatePrefer1st Alternate
Criteria of Success:1. Ability to make Window
Joint.2. Select brazements that are
leak tight3. Ability to make Body joint
compatible with Window Joint4. Ability to repair Body leaks
Join Window to Transition then to Body
Criteria of Success:1. Cu-Au Braze Transition to
Body2. Ability to make Window
Joint with transition on body.3. Ability to repair Windows
leaks
Join Transition to Body then join Window
Criteria of Success:1. Ability to make Window
Joint.2. Select brazements that are
leak tight4. Ability to repair Window
leaks
Join Window to Transition
Criteria of Success:1. Cu-Au Braze Transition to
Body2. Ability to repair joint
Join Transition to Body
Criteria of Success:1. Prove ability to make joint
while on the Body2. Ability to Repair leaks
3. Ability to disassemble and replace window
Mid Transition Joint
Criteria of Success:1. Ability to make Joint to
Body at less than 650 deg C2. Ability to repair leaks
3. Ability to remove Transition assembly from Body
Join Transition to Body
Jan. 22-23, 2008LCLS Undulator Week
5 Dean R. Walters
Two Piece Transition
J1 J2 J3
Au-Ge E-Beam Au-Cu
Au-Sn Laser Au-GeH2
Sn-Ag-CuOther
H2
Sn-Ag-Cu
J1
J3
J2
Jan. 22-23, 2008LCLS Undulator Week
6 Dean R. Walters
Alternative 2 Piece Joints
Internal Moly retaining ring Kovar Frame for E-Beam welding window
External Moly retaining ring
Jan. 22-23, 2008LCLS Undulator Week
7 Dean R. Walters
LogicSoldering without windows breakage
There are three cases: (1) zero or low yield like less than 50%, (2) some usable yield like 51% to 99%, or (3) 100 %. The results at this point is:
Sn-Ag-Cu soldering is 100%Orotin is ~50%Georo by itself is less than 50%Georo with a Moly ring is 100%
Repairing a solder or braze leakGeoro
Testing has shown that its re-melt temperature is higher that initial. This allows re-running the part with repair Georo to seal any leaks.
Sn-Ag-Cu Testing in hydrogen to repair leaks have been unsuccessful.
Removal & Replacement of WindowsNo matter what joining technique is chosen: Brazing, soldering, or welding; if the windows cannot be replaced due to gross mishandling than this is a concern.By choosing a de-mountable transition to body joint than this concern can be overcome.Additionally if the design uses some kind of two piece design and the attachment can be machined out (without getting chips into the cavity) then any technique is usable.
Can a window be soldered without breaking?
Can a solder joint having a vacuum leak be repaired?
Can a broken window be removed and replaced?
Any technique that cannot be repaired should be eliminated
If a technique having 100% yield cannot be determined then the only useful approach is to be able to select good units
The only useful technique is machining it out, chips falling into cavity a major
concern
NO
Yes
Yes
Yes
NO
NO
Jan. 22-23, 2008LCLS Undulator Week
8 Dean R. Walters
Good Georo Joint in December
This was done after increasing the dimensions of the opening and braze in
ANL’s furnace at 400 deg C
Jan. 22-23, 2008LCLS Undulator Week
9 Dean R. Walters
Large Moly Ring for Controlling Copper Expansion
External Moly Ring
Jan. 22-23, 2008LCLS Undulator Week
10 Dean R. Walters
Small Moly Ring for Controlling Copper Expansion
Internal Moly Ring
Jan. 22-23, 2008LCLS Undulator Week
13 Dean R. Walters
Results of SN-Au (Orotin) run at Altair
Jan. 22-23, 2008LCLS Undulator Week
14 Dean R. Walters
Orotin Samples Viewed from the Reverse Side
Jan. 22-23, 2008LCLS Undulator Week
15 Dean R. Walters
Status of EffortSelect ResultsWindow Joint
Larger dimensionsMeasured 30 windows and increased dimensions by .3 mmTest piece using Georo did not crack or leak in 1 of 1 pieceTest pieces using Orotin leaked in 3 of 3 pieces and only 1 cracked
Stress relief grooveIn test pieces a .8 mm wide land was includedTest piece using Georo leaked in 1 piece of 1.3 test pieces using Orotin did not leak and had 1 cracked frit.
Moly retaining rings added to limit copper expansion
2 Parts with internal Moly ring were soldered with Georo and there were no leaks2 Parts with external Moly ring were soldered with Georo and there were no leaks2 Parts with using external Moly ring (no relief groove) were soldered with Georo and there were no leaks
PlatingNickel Only
Windows fired at 450 C in H2, found 3 parts in 8 with blistersCPI will fire parts at 600 deg C before shipping to ANL
Gold/NickelWilliams suggests using gold as a oxygen barrier for nickel.Gold is very useful for soldering below 300 deg C
2 Piece Transition Microwave transmission
Test of prototype parts show that small mismatch will not degrade performance
Sn-Ag-CuLiquid Flux RGA tests
First test used windows and copper parts, after 24 hours of baking at 150 deg C a residue of the flux is present
Liquid Flux heated with a Hot PlateA fluxed part made leak tight joint without cracking the window
Hydrogen Gas as a fluxTest with gold plating at 220 deg C had leaks but did not crack the window.A tests at 230 deg C showed good wetting of the copper by the solder materialReran windows with vacuum leak at 250 deg C and was not able make it leak tight.
Jan. 22-23, 2008LCLS Undulator Week
16 Dean R. Walters
RGA Analysis of the GAH Flux Solder Samples
-Here are the peaks (30,36,46,60, & 78)
MW=78MW=60
MW=46
MW=36
MW=30
Jan. 22-23, 2008LCLS Undulator Week
17 Dean R. Walters
Results at AltairS/N Test
LocationMaterial Leak Glass Frit Filler Thk Joint
PrepPlating
2a-68 Altair Sn-Au 355 C Yes OK OK Single Std Au
2a-69 Altair Sn-Au 355 C No OK OK Single Grv Au
2a-90 Altair Sn-Au 355 C Yes Crk OK Single Std Ni
2b-61 Altair Sn-Au 355 C No OK OK Single Grv Au
2b-67 Altair Sn-Au 355 C Yes OK OK Single Std Au
2b-89 Altair Sn-Au 355 C No OK Crk Single Grv Ni
91 Altair Sn-Au 320 C No OK OK Double Std Ni
92 Altair Sn-Au 320 C Yes Crk Crk Double Grv Ni
93 Altair Sn-Au 320 C No OK OK Single Std Ni
94 Altair Sn-Au 320 C No ?- OK Crk Single Grv Ni
95 Altair Sn-Au 320 C Yes Crk Crk Single Std Ni
96 Altair Sn-Au 320 C Yes Crk Crk Single Grv Ni
Jan. 22-23, 2008LCLS Undulator Week
18 Dean R. Walters
Results at ANLDate or S/N
Test Location
Material Leak Glass Frit Filler Thk Joint Prep
Plating
72 ANL Sn-Ag-Cu 230 C Yes OK OK Single Grv Au
62 ANL Sn-Ag-Cu 230 C Yes OK OK Single Grv Au
1/18 ANL Rflw Sn-Ag-Cu 250 C Yes OK OK Single Grv Au
1/18 ANL Sn-Ag-Cu 230 C Yes OK OK Double Grv Au
184S ANL Georo 400 C Lg Mo No OK Spl Double Grv Ni
185S ANL Georo 400 C Lg Mo No OK Spl Double Grv Ni
1/22 ANL -2 Georo 400 C Lg Mo No OK OK Double Lg Std Ni
1/22 ANL -2 Georo 400 C Lg Mo No OK OK Triple Lg Std Ni
Jan. 22-23, 2008LCLS Undulator Week
19 Dean R. Walters
ScheduleWeek ending Jan 18
Large Moly Ring Sn/Ag/Cu solder at 230 C in hydrogen furnace First attempt of Laser weldingTest using Orotin at Altair
Week ending Jan 25Fab test parts for 2nd round of Laser weldingSn/Ag/Cu solder at 250 C in hydrogen furnaceResults of FEA analysis on Moly rings Initial results from Induction Heating vendorSection parts from Altair test
Week ending Feb 1Moly retainer using Orotin at 320-350 CLaser weld test partsSend additional parts to Induction Heating vendorDesign and fab Laser test parts with improved weld prep
Week ending Feb 8Run tests using induction heating
Week ending Feb 15Meeting on Window soldering
Jan. 22-23, 2008LCLS Undulator Week
20 Dean R. Walters
Pro/Con of Designs
Design Pro Con
1 Piece Design
Faster to bring into production More difficult to replace Window
Plan uses pre-tested window Modification to parts required
Can use existing parts Need low temperature joint to attach transition to body
2 Piece Design
Ability to pre-test window joint Must make new transitions
Easiest to replace window Longer Lead Time
Potential to have interchangeable parts
Need to develop weld process
CPI Window Assy
CPI will deliver leak tight Window assemblies
Copper plating unknown
Hard braze expected to be highly reliable
CPI parts will be costly and take the longest to produce
CPI responsible for quality Have seen evidence of questionable CPI quality
Jan. 22-23, 2008LCLS Undulator Week
21 Dean R. Walters
Details to the 1 Piece Transition Plan
Braze at ANL 10 transitions using Georo with the Large Moly Ring
After thermal cycling and leak checking select 5 units for shipment to the braze vendor.
Braze vendor will use [Georo or Sn-Au] braze to attach transitions to body.
Back up is to use the 5 steel transition from CPI and prep them in case they are needed.
Jan. 22-23, 2008LCLS Undulator Week
22 Dean R. Walters
Issues with this plan
1. While good yield has been seen with the Moly ring and Georo the question of re-running the part to seal a leak has been not shown.1. Can Georo be used to reseal a leak or something else.2. Is there a technique for windows removal from the
transition for the purpose of rework. 2. The joint material for joining the transition to the
body needs to determined. 1. Is the removal of the transition from the body, in the
event of breakage, better suited to either Georo or Sn-Au.
3. A plan for determining these issues is ongoing.
