Crucibles and compositions and processes for making same

Patent metadata

Field	Value
Publication number	US-2022212998-A1
Application number	US-202017604325-A
Country	US
Kind code	A1
Filing date	Apr 16, 2020
Priority date	Apr 17, 2019
Publication date	Jul 7, 2022
Grant date	—

Abstract

A crucible having a heat treated body. The heat treated body comprises a composition including an oxide material, from 5 wt % to 50 wt % a nitride material, and optionally a sintering aid. A weight ratio of the nitride material to the oxide material ranges from 0.02:1 to 2.0:1. The heat treated body has an oxide material lattice structure with nitride material at least partially encapsulated therein.

First claim

We claim:

1 . A crucible having a heat treated body, the heat treated body comprising a composition including:
an oxide material; from 5 wt % to 50 wt % a nitride material; and optionally a sintering aid; wherein a weight ratio of the nitride material to the oxide material ranges from 0.02:1 to 2.0:1, and wherein the heat treated body has an oxide material lattice structure with nitride material at least partially encapsulated therein.

2 . The crucible of claim 1 , wherein a weight ratio of the nitride material to sintering aid ranges from 2:1 to 100:1.

3 . The crucible of claim 1 , wherein the oxide material comprises aluminum oxide, beryllium oxide, or yttrium oxide, or combinations thereof.

4 . The crucible of claim 1 , wherein the nitride material comprises boron nitride.

5 . The crucible of claim 1 , wherein the sintering aid comprises rare earth metal, fumed silica, magnesium oxide, petalite, tetraethyl orthosilicate, or magnesium trisilicate, or combinations thereof.

6 . The crucible of claim 1 , wherein at least 10% of the nitride material is at least partially encapsulated in the oxide material lattice structure.

7 . The crucible of claim 1 , wherein in the heat treated body, boron nitride is at least partially encapsulated such that boron nitride comprises less than 50% of a surface area of an exterior surface of the heat treated body.

8 . The crucible of claim 1 , wherein the encapsulation of the nitride material is achieved by heat treating a precursor composition to form the heat treated body comprising a heat treated composition, and wherein the precursor composition comprises an oxide material, a nitride material, and a sintering aid.

9 . The crucible of claim 1 , wherein the heat treated body further comprises nitrided aluminum co-product and/or oxided boron co-product

10 . The crucible of claim 1 , wherein, when contacted with molten metal at temperatures below 1700° C., less than 5% of the contacted surface area is adhered to by the molten metal.

11 . The crucible of claim 1 , wherein, when contacted with molten metal at temperatures greater than or about 1550° C. or above, less than 5% of the contacted surface area is adhered to by the molten metal.

12 . The crucible of claim 1 , wherein, when contacted with molten metal at temperatures greater than or about 1550° C., the wetting angle of the molten metal is greater than 90 degrees.

13 . The crucible of claim 1 , wherein the heat treated body defines a volume of 1 cm 3 to 5000 cm 3 for holding a molten metal.

14 . The crucible of claim 1 , wherein the heat treated body has an average wall thickness ranging from 2 mm to 25 mm.

15 . The crucible of claim 1 , wherein, after exposure to at least 10 cycles of 68% nitric acid cleaning, the heat treated body retains at least 99% of the initial hardness.

16 . The crucible of claim 1 , wherein the composition comprises less than 1 wt % carbon.

17 . A process for producing a crucible having a heat treated body, the method comprising:
providing an oxide material, optionally in a powder form; providing a nitride material, optionally in a powder form, in an amount from 10 wt % to 50 wt %; providing a sintering aid; mixing the oxide material, the nitride material, and the sintering aid to form a precursor composition; wherein a weight ratio of the nitride material to the oxide material in the precursor composition ranges between 0.05:1 and 2.0:1; shaping the precursor composition; and heat treating the shaped composition to form the heat treated body; wherein in the heat treated body, the nitride material is at least partially encapsulated in an oxide material lattice structure.

18 . The process of claim 17 , wherein the precursor composition comprises an initial amount of nitride material and the heat treated body comprises a heat treated amount of nitride material and wherein the heat treated amount is less than the initial amount.

19 . The process of claim 17 , further comprising mixing the precursor composition with a binder, and spray drying the precursor composition mixed with the binder into agglomerates having an average diameter ranging from 40 microns to 120 microns.

20 . An oxide/nitride composition comprising:
an oxide material; from 5 wt % to 50 wt % a nitride material; and optionally a sintering aid; wherein a weight ratio of the nitride material to the oxide material ranges from 0.02:1 to 2.0:1, and wherein the composition may form an oxide material lattice structure with nitride material at least partially encapsulated therein.

Assignees

• Materion Corp

Inventors

• Aslett Zan
• Grensing Fritz
• Morey Evan K

Classifications

• C04B35/08

  based on beryllium oxide · CPC title

• C04B35/505

  based on yttrium oxide · CPC title

• C04B2235/95

  Products characterised by their size, e.g. microceramics · CPC title

• C04B2235/9676

  against molten metals such as steel or aluminium · CPC title

• C04B2235/441

  Alkoxides, e.g. methoxide, tert-butoxide · CPC title