WP4 cooling update RAL 6th Oct 2011 -

Welding – high repeatability statisticsBending – 2.275mm OD trials in Titanium with

comparison of 1.8” OD bend testsDatabase – how it is starting to shape upPlans for AUW

Plans for AUW

• Welding next to electronics– 2nd weld system purchased and delivered to RAL (still in boot of car but on site)– JM to run tests on FEI4 130nm structure – still waiting for readout. – May use simpler test on FEI4 but struggling to get test structures.– Still looks possible to get data and written up for presentation at AUW– Need representative test structure as still outstanding

• Welding of tube– Stainless stats – present at AUW– Ti stats should be done in 1/8” OD for AUW (same as SS but some of the

testing results may not be returned in ti me)– Will aim to get images on slides of 2mm bore Ti welds –

used flared end to bring extra material to joint but get bulbous weld bead

• I also will need to take a holiday this year so need to factor this in after AUW looks like most of Dec/early Jan.

Welding repeatability statistics 14/9Weld No. Electrode use Gas pressure Comments Action

3 ? 8.8 Ok -

4 ? 8.8 Concave weld bead Premeasured purge and reset

5 ? 8.9 Poor Weld holes blown – restarted and fixed Change electrode for new

12 6 8.8 Blow out & pin holes Checked and reset alignment of fixture block

31 25 8.8 Blow out – 14/9/11 9am first weld of day Run test weld round scrap tube for machine to warm

52 46 8.9 Weld fail warning Checked no reason for fail – restarted and weld ok

53 47 8.8 Weld fail warning Checked no reason for fail – restarted and weld ok, changed electrode

54 1 8.8 Perfect Run out of tube lunchtime 14.9.11

Alterations to process and conclusions:• Lab rats: Using 2x mech workshop techs I gave one demonstration of welding & zero instruction other than follow my

flow/process chart and press go. It took both 8 – 10 welds to get the hang of the alignment until we repositioned the fixture block collets. I then used tech 2 to press go with zero instruction , followed chart & perfect welds every time.

• Why the early failures? = Old electrode used for unknown number of welds.• Why does the machine bring up the weld fail warning consecutively – the machine senses the wear on the electrode and

fails to start- this can be repeated twice only before holes appear in the tube• The tubes were even lenghts to enable the setting of the gas pressure once only – this was not the case, the gas pressure

varied throughout the day. The flow meter was poor and replaced, the internal flow/pressure gauge is not so accurate. Borrowing a automatic pressure valve led to exact setting of the gas pressure at the joint – will now implement as may aid purge gas measurement in large volume systems.

Weld stats 26/9 to 03/10/11Weld No. Electrode use Gas pressure Comments Action

55 1 8.8 First of day with new electrode, weld perfect but slightly darker HAZ than before

64 9 8.8 Perfect 2 hour break needed to finish other jobs

66 11 8.8 Blow out - poor joint, electrode contaminated Changed electrode – gas purge re-measured at 7.0 so too low

67 1 8.8 Perfect Gas set up working fine and repeatable

80 13 8.8 Perfect Overnight break

100 33 8.8 Perfect Gas low so bottle change needed

105 38 8.8 Concave weld, gas pressure out again Flow meter sticking and repaired

106 39 8.8 Blow out Weld fail warning, flow meter & over pressure

118 51 8.8 Failed Electrode needed changing at 30 as sporadic results with multiple problems to push life to 50 cycles

119 1 8.8 Prefect Carry on!

129 30 8.8 Perfect Electrode change

159 30 8.8 Perfect Electrode change

189 30 8.8 Perfect Electrode change

459 30 8.8 Perfect Electrode Change, PKR is fed up of welding

• Electrode life understood – gas purge and pressure fixed , operators familiar with kit, • 360 perfect welds in a row, zero failures. Took 2 sessions to iron glitches out before highly repeatable process.• Repeat welds every time and now at 489welds without failure on 5 th Oct 2011. Going for 500.

Early weld statistics conclusions

• Early results so still a few to go.• Once glitches in system worked out, 2 people with minimal training have now

produced 360 consecutive welds in 316L stainless steel without a single failure. Will stop at 500 consecutive welds as only enough material for 511.

• It took 119 welds to fully refine the process to very high repeatability, roughly 2 sessions looking at the problems.

• Electrode life is now safely set at 30 uses. Each electrode is £6.05 so £0.20 per weld.

• Gas purge system– Accurate pressure measurement needs to be permanently implemented - borrowed automatic

pressure valve and sensor – delivers constant pressure to sensor at joint. Only problem is that have to disconnect tee piece for weld. Might try and work out pressure at end of x mm gives x pressure at joint. Not so easy as need to normalise with temperature.

• OUTSTANDING WORK ON 316L Tube– NDT results not returned yet. DT results not returned. Still struggling for a reliable tensile test due to

problematic mounting of the tube on the strain jigs – universal– Writing up – publication.

• Titanium– Will repeat for 3.175mm OD titanium. Have enough material for 700 welds.

Titanium Bend Tests

RAL. 6th October, 2011Ian Mercer & Richard French

Titanium1/8" Bend

Radius Min out of roundness% of dia % reduction

Max out of roundness %increase15 3.05 98.39 -1.61 3.12 100.65 14 3.03 97.74 -2.26 3.13 100.97 13 3.02 97.42 -2.58 3.14 101.29 12 2.99 96.45 -3.55 3.12 100.65 11 2.98 96.13 -3.87 3.11 100.32 10 2.98 96.13 -3.87 3.13 100.97 9 2.97 95.81 -4.19 3.15 101.61 8 2.91 93.87 -6.13 3.15 101.61 7 2.75 88.71 -11.29 3.15 101.61 6 2.38 76.77 -23.23 3.16 101.94 5 2.27 73.23 -26.77 3.17 102.26 3.1

Titanium2.275mm Bend

Radius Min out of roundness% of dia % reduction

Max out of roundness %increase15 2.19 70.65 -29.35 2.21 71.29 14 2.19 70.65 -29.35 2.21 71.29 13 2.19 70.65 -29.35 2.22 71.61 12 2.18 70.32 -29.68 2.23 71.94 11 2.17 70.00 -30.00 2.23 71.94 10 2.13 68.71 -31.29 2.24 72.26 9 2.11 68.06 -31.94 2.26 72.90 8 2.07 66.77 -33.23 2.26 72.90 7 1.98 63.87 -36.13 2.27 73.23 6 1.91 61.61 -38.39 2.27 73.23 5 1.84 59.35 -40.65 2.37 76.45 2.22

1/8” Titanium TubeThe Tube bent quite nicely with little spring back as you can see in the graph the min out of roundness gets better at 8mm radius the max out of roundness will not change much because it is captured in the radius of the tooling.On visual inspection the tube has creases and signs of flattening on the outside of the radius for the 5,6,and 7mm radius, and then at 8mm and above the bend looks fine.Summary Good tube to bend has little spring back which makes it easier to bend to dimensions, the smallest bend radius that we can bend without defects is 8mm.

2.275mm Titanium TubeThis tube is fairly difficult to bend due to the spring back, this makes it harder to bend to the radius and dimensions, in the graph the min out of roundness gets better at 9mm radius as with the other tube the max out of roundness will not change much as it is captured in the tooling radius.On visual inspection the tube has creases and flattening on the 5,6, and 7mm radius, on 8mm and above there are no visual defects.SummaryDifficult tube to bend with the large spring back, bending to the dimensions is a lot harder, but can be done with experience on how much to compensate for with the spring back, smallest radius we can bend without defects is 9mm.

Atlas Upgrade Construction DB● 3 sites:

– Development

– Test

– Production

● Progressing with the “admin” interface

● Test users have access to system

http://aucdbtest.ph.qmul.ac.uk/admin/

Alex Owen, Alex Martin, Martin Gibson