CLIC Meeting 21/08/2001

G. Arnau Izquierdo EST/SM

1

W single crystal W single crystal advancement. advancement.

1) Manufacturing.

2) Images after EDM.

3) Images after grinding.

3) Images after electropolishing.

4) Conclusions.

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

2

Manufacturing of discs.Manufacturing of discs.W single crystal

EDM: Electrical Discharge Machining = Electro-erosionEP: Electropolishing

EDM cutting

Grinding

EP: -12.6µm

EDM conditions are similar than for the CERN Workshop irises. They can be optimised for better finishing.

Grinding was feasible: all three were accidentally banged only one broke.

Only a first EP step.

?

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

3

As Electrical Discharge As Electrical Discharge Machined.Machined.

Severe surface cracking.Severe surface cracking. Cracks follow well defined Cracks follow well defined

crystallographic directions.crystallographic directions. Flakes 35µm deep.Flakes 35µm deep.

400µm 50x

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

4

As Electrical Discharge Machined.As Electrical Discharge Machined.

20µm

100µm

1000x

200x

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

5

After grindingAfter grinding

Cracks are no apparent.Cracks are no apparent. Similar to Plansee.Similar to Plansee.

20µm 1000x

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

6

After ElectropolishingAfter Electropolishing Good smoothensGood smoothens Electrolyte agitation problemElectrolyte agitation problem Traces of cracksTraces of cracks

400µm 50x

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

7

FlueckigerFlueckigerBefore Electropolishing (2/2)Before Electropolishing (2/2)

20µm

100µm

1000x

200x

CLIC Meeting 21/08/2001 G. Arnau Izquierdo EST/SM

8

Conclusions.Conclusions.

The effect of Electrical Discharge The effect of Electrical Discharge Machining is worst than for Machining is worst than for polycrystalline tungsten.polycrystalline tungsten.

Intense EP could be needed to get a Intense EP could be needed to get a smooth surface.smooth surface.

EDM parameters can be further EDM parameters can be further improved.improved.

Grinding is feasible. The feasibility of Grinding is feasible. The feasibility of drilling the hole is to be checked.drilling the hole is to be checked.

Good smoothness after EP of the Good smoothness after EP of the ground surface . First test to be ground surface . First test to be improved.improved.