AN ARTICLE COMPRISING A COMPOSITE COMPRISING GRAPHITE
A method of forming an article that includes a composite including graphite is disclosed. The article is suitable for containing or processing a molten metal such as aluminum. The method includes forming at least one granulated mixture by mixing at least carbon black, flake graphite, needle coke with at least one resin, the at least one resin has a flow distance, as measured by ISO 8619:2003, from 20 mm to 150 mm. The method further includes shaping the granulated mixture into a shaped body and firing the shaped body.
1 . A method of forming an article comprising a composite comprising graphite, wherein the article is suitable for containing or processing a molten metal, the method comprising:
(a) forming at least one granulated mixture by mixing at least carbon black, flake graphite, needle coke with at least one resin, wherein the at least one resin has a flow distance, as measured by ISO 8619:2003, from 20 mm to 150 mm;
(b) shaping the at least one granulated mixture into at least one shaped body; and
(c) firing the at least one shaped body.
2 . The method of claim 1 , wherein, relative to the total weight of the granulated mixture:
the carbon black is present in the granulated mixture in an amount from about 5 weight percent to about 10 weight percent,
the flake graphite is present in the granulated mixture in an amount from about 65 weight percent to about 85 weight percent,
the needle coke is present in the granulated mixture in an amount from about 1 weight percent to about 5 weight percent, and
the resin is present in the granulated mixture in an amount from about 2 weight percent to about 10 weight percent.
3 . The method of claim 1 , wherein, at least one solvent is added to the at least one resin to form at least one binder system consisting of the at least one resin and the at least one solvent.
4 . The method of claim 3 , wherein the at least one solvent is present in the granulated mixture in an amount from about 1 weight percent to about 5 weight percent, relative to the total weight of the granulated mixture.
5 . The method of claim 1 , wherein the at least carbon black, the flake graphite, the needle coke, and the at least one resin provide 100 percent of a total weight of the granulated mixture.
6 . The method of claim 1 , wherein the at least one granulated mixture further comprises from about 5 weight percent to about 15 weight percent of at least one anti-oxidation additive, relative to the total weight of the granulated mixture, wherein optionally the at least one anti-oxidation additive comprises boron carbide, silicon carbide, aluminum-zinc phosphate, or any combination thereof.
7 . The method of claim 1 , wherein the at least one granulated mixture further comprises from about 1 weight percent to about 5 weight percent of at least one toughening/strength enhancing additive, relative to the total weight of the granulated mixture, wherein optionally the at least one toughening/strength enhancing additive comprises carbon fibers, chopped carbon fiber bundles, basalt bundles, alumina silicate fibers, chopped steel fibers or any combination thereof.
8 . The method of claim 1 , wherein the granulated mixture further comprises from about 1 weight percent to about 10 weight percent of at least one wear/erosion resistance agent, relative to the total weight of the granulated mixture, wherein optionally the at least one wear/erosion resistance agent comprises a metal oxide, a metal nitride, a metal boride, or any combination thereof.
9 . The method of claim 1 , wherein the at least one granulated mixture further comprises from about 1 weight percent to about 5 weight percent of a thermal insulation enhancing agent, relative to the total weight of the granulated mixture, and wherein optionally the at least one thermal insulation enhancing agent comprises colloidal silica shots, preferably alumino colloidal silicate shots, fibers, preferably a mixture of sodium and chopped silica fibers, or a mixture thereof.
10 . The method of claim 1 , wherein at least part of the composite is infiltrated with a siloxane, a selected phosphate solution or any combination thereof prior to, or after, the firing step.
11 . The method of claim 1 , wherein the resin is phenolic resin, wherein optionally the phenolic resin is a liquid phenolic resin.
12 . An article comprising a composite comprising graphite, wherein the composite has a total pore volume and a pore size distribution, measured according to ASTM C830-00(2016) Standard, wherein at least 95 percent of the total pore volume is contained in pores with a diameter of less than 1 μm, and at least 40 percent of the pore volume of the pores having a diameter of less than 1 μm is contained in pores having a diameter of less than 0.1 μm.
13 . The article of claim 12 , wherein the composite has a density from about 1.6 g/cm 3 to about 1.92 g/cm 3 .
14 . The article of claim 12 , wherein the composite has 65% or more of graphite.
15 . The article of claim 12 , wherein the composite has a surface roughness R a between 3.2 μm and 0.025 μm, wherein the surface roughness R a is measured based on the ISO 1302:1992 standard.
16 . The article of claim 12 , wherein at least part the composite is further coated with a coating.
17 . The article of claim 12 , wherein the article is a crucible, said crucible being comprised of a plurality of crucible rings which are stacked uniformly on top of one another in order to provide the crucible.
18 . An article comprising a composite comprising graphite obtained by the method of claim 1 .
19 . The article of claim 18 wherein the composite has a total pore volume and a pore size distribution, measured according to ASTM C830-00(2016) Standard, wherein at least 95 percent of the total pore volume is contained in pores with a diameter of less than 1 μm, and at least 40 percent of the pore volume of the pores having a diameter of less than 1 μm is contained in pores having a diameter of less than 0.1 μm.
20 . The article of claim 18 wherein at least part the composite is further coated with a coating.
21 . (canceled)