Ribbon Crystal String with Extruded Refractory Material

1 . A method of making string for string ribbon crystal, the method comprising:

providing a substrate having an outer surface;

extruding refractory material over the substrate, the refractory material substantially covering the outer surface of the substrate;

curing the refractory material.

2 . The method as defined by claim 1 wherein the substrate comprises a carbon filament.

3 . The method as defined by claim 1 wherein the refractory material comprises silicon carbide.

4 . The method as defined by claim 1 wherein the substrate comprises a tow.

5 . The method as defined by claim 1 further comprising forming an exterior reduced wetting layer radially outward of the refractory material.

6 . The method as defined by claim 1 wherein the substrate and refractory material form a generally elongated cross-sectional shape.

7 . The method as defined by claim 1 wherein the substrate and refractory material are generally concentric.

8 . A string for forming a ribbon crystal, the string comprising:

a substrate having an outer surface; and

an extruded refractory material layer substantially covering the outer surface of the substrate.

9 . The string as defined by claim 8 wherein the substrate comprises a carbon filament.

10 . The string as defined by claim 8 wherein the refractory material comprises silicon carbide.

11 . The string as defined by claim 8 wherein the substrate comprises a tow.

12 . The string as defined by claim 8 further comprising an exterior reduced wetting layer radially outward of the refractory material.

13 . The string as defined by claim 8 wherein the substrate and refractory material form a generally elongated cross-sectional shape.

14 . The string as defined by claim 8 wherein the substrate and refractory material are generally concentric.

15 . The string as defined by claim 8 further comprising a handling layer radially outward of the refractory material.

16 . A string for forming a ribbon crystal, the string comprising:

a substrate; and

extruded refractory means substantially covering the substrate.

17 . The string as defined by claim 16 wherein the extruded refractory means comprises a refractory material.

18 . The string as defined by claim 16 wherein the substrate comprises a carbon filament.

19 . The string as defined by claim 16 wherein the extruded refractory means comprises silicon carbide.

20 . The string as defined by claim 16 wherein the substrate comprises a tow.

21 . The string as defined by claim 16 further comprising an exterior reduced wetting layer radially outward of the extruded refractory means.