Racks for high-temperature metal processing
View Patent ↗In various embodiments, apparatuses for receiving and supporting one or more components during processing thereof at process temperatures greater than approximately 1000° C. feature refractory metal shelves separated by refractory metal support posts.
1. An apparatus for receiving and supporting one or more components during processing thereof at a process temperature greater than approximately 1000° C., the apparatus comprising:
a first shelf comprising a first refractory metal having a melting point greater than the process temperature;
a second shelf (i) comprising a second refractory metal having a melting point greater than the process temperature, and (ii) comprising one or more first lift hooks extending therefrom; and
a plurality of first support posts, each first support post (i) comprising a third refractory metal having a melting point greater than the process temperature, (ii) configured to extend between the first shelf and the second shelf, (iii) having an upper end and a lower end opposite the upper end, and (iv) having a lower end for engagement with an aperture of the first shelf,
wherein the second shelf and the first support posts are collectively separable, as a modular unit, from the first shelf via a lifting force applied via the one or more first lift hooks.
2. The apparatus of claim 1 , wherein the first shelf defines therein a plurality of apertures, the lower end of each first support post being configured to be received within one of the apertures.
3. The apparatus of claim 2 , wherein the lower end of each first support post is tapered.
4. The apparatus of claim 1 , wherein the upper end of each of the first support posts is threaded.
5. The apparatus of claim 1 , wherein:
the second shelf defines a plurality of apertures defined therethrough; and
each of the first support posts defines a support collar proximate the upper end, a lateral dimension of the first support post above the support collar being smaller than a lateral dimension of the first support post below the support collar, whereby, when an upper end of a first support post is received in an aperture of the second shelf, a portion of the second shelf proximate the aperture rests upon the support collar of the first support post received in the aperture.
6. The apparatus of claim 1 , wherein at least one of the first, second, or third refractory metals comprises a TZM alloy.
7. The apparatus of claim 6 , wherein the TZM alloy comprises approximately 0.40 approximately 0.55 weight percent Ti, approximately 0.06 approximately 0.12 weight percent Zr, and the balance Mo.
8. The apparatus of claim 1 , wherein at least one of the first, second, or third refractory metals comprises at least one of Nb, Ta, Re, W, or Mo.
9. The apparatus of claim 1 , wherein
the second shelf defines a plurality of apertures defined therethrough; and
the upper end of each of the first support posts is configured to protrude through one of the apertures.
10. The apparatus of claim 9 , further comprising a plurality of first nuts, each first nut (i) comprising a fourth refractory metal having a melting point greater than the process temperature, and (ii) being configured to engage with the upper end of one of the first support posts to thereby secure the one of the first support posts to the second shelf.
11. The apparatus of claim 10 , wherein each first nut defines therein a lower aperture, at least a portion of the lower aperture being threaded for engagement with the upper end of one of the first support posts.
12. The apparatus of claim 11 , wherein each first nut defines therein an upper aperture.
13. The apparatus of claim 12 , wherein at least a portion of the upper aperture is tapered.
14. The apparatus of claim 12 , further comprising:
a third shelf comprising a fifth refractory metal having a melting point greater than the process temperature; and
a plurality of second support posts, each second support post (i) comprising a sixth refractory metal having a melting point greater than the process temperature, (ii) configured to extend between the second shelf and the third shelf, (iii) having an upper end and a lower end opposite the upper end, and (iv) having a lower end for engagement with an upper aperture of one of the first nuts.
15. The apparatus of claim 1 , further comprising:
a first support tube (i) having an upper end and a lower end opposite the upper end, (ii) comprising a fourth refractory metal having a melting point greater than the process temperature, and (iii) configured to extend from the first shelf to the second shelf, wherein the upper end of the first support tube defines therein a plurality of notches; and
a support brace comprising a plurality of appendages for supporting the second shelf thereon, each appendage being configured for receipt into one of the notches of the upper end of the first support tube.
16. The apparatus of claim 15 , further comprising, disposed below the first shelf, a shelf support comprising a plurality of interconnected cross braces, each cross brace comprising a fifth refractory metal having a melting point greater than the process temperature.
17. The apparatus of claim 16 , wherein:
the first shelf defines a central aperture therethrough; and
the lower end of the first support tube defines a plurality of notches and is configured to extend through the central aperture of the first shelf, each of the notches being configured to receive therein one of the cross braces of the shelf support.
18. The apparatus of claim 16 , further comprising, disposed beneath the shelf support, a base comprising (i) a plurality of spaced-apart cross bars each defining a plurality of apertures therethrough, and (ii) a plurality of spaced-apart through rods each extending through the apertures of multiple ones of the cross bars.
19. The apparatus of claim 18 , wherein:
the base comprises one or more alignment features extending upward therefrom; and
the shelf support comprises one or more brackets each for receiving one of the one or more alignment features.
20. The apparatus of claim 15 , further comprising a second support tube (i) having an upper end and a lower end opposite the upper end, and (ii) comprising a fifth refractory metal having a melting point greater than the process temperature, wherein (a) the second shelf defines a central aperture therethrough, and (b) the lower end of the second support tube is configured to extend through the central aperture of the second shelf and defines therein a plurality of notches, each notch configured to receive therein one of the appendages of the support brace.
21. The apparatus of claim 1 , further comprising, disposed beneath the first shelf, a base comprising (i) a plurality of spaced-apart cross bars each (a) defining a plurality of apertures therethrough and (b) comprising a fourth refractory metal having a melting point greater than the process temperature, and (ii) a plurality of spaced-apart through rods each (a) extending through the apertures of multiple ones of the cross bars and (b) comprising a fifth refractory metal having a melting point greater than the process temperature.
22. The apparatus of claim 21 , further comprising, disposed below the first shelf and above the base, a shelf support comprising a plurality of interconnected cross braces, each cross brace comprising a sixth refractory metal having a melting point greater than the process temperature.
23. The apparatus of claim 22 , wherein:
the base comprises one or more alignment features extending upward therefrom; and
the shelf support comprises one or more brackets each for receiving one of the one or more alignment features.
24. A method of high-temperature brazing at a process temperature greater than approximately 1000° C., the method comprising:
disposing within a furnace chamber an apparatus comprising:
a first shelf comprising a first refractory metal having a melting point greater than the process temperature,
a second shelf (i) comprising a second refractory metal having a melting point greater than the process temperature, and (ii) comprising one or more first lift hooks extending therefrom, and
a plurality of first support posts, each first support post (i) comprising a third refractory metal having a melting point greater than the process temperature, (ii) configured to extend between the first shelf and the second shelf, (iii) having an upper end and a lower end opposite the upper end, and (iv) having a lower end for engagement with an aperture of the first shelf,
wherein the second shelf and the first support posts are collectively separable, as a modular unit, from the first shelf via a lifting force applied via the one or more first lift hooks;
disposing on the first shelf or the second shelf of the apparatus (i) a first component, (ii) a second component, and (iii) a brazing material disposed between the first and second components;
introducing within the furnace chamber a processing ambient; and
applying the process temperature within the furnace chamber, thereby melting the brazing material and joining the first and second components at a brazed joint therebetween.
25. The method of claim 24 , wherein introducing the processing ambient comprises at least partially evacuating the furnace chamber.
26. The method of claim 24 , wherein introducing the processing ambient comprises introducing a process gas within the furnace chamber.
27. The method of claim 26 , wherein the process gas comprises hydrogen.