Graphite, pyrolytic graphite, glassy carbon

Brazing

Sourced pairings

Preparation

• none
• the Ticusil foil placed in direct contact with the graphite surface on a tapered joint interface, with a slight pressure applied at the interface during brazing to obtain a void-free joint. On this joint the alumina is UNMETALLIZED.
• the graphite is metallized with a molybdenum, manganese and silica powder slurry brush-painted, dried and fired at 1600 C in dry hydrogen to form carbides with the graphite, the alumina ring is metallized on both its inner and outer circumferential surfaces, a thin copper coating overlaid on the graphite serves as the filler and protects the metallization from oxidation. Both brazes, Kovar to alumina and alumina to graphite, are made in a single operation.

Compatibility

What documents state about this material faced with a filler metal, without the other member of the joint. A statement that names the exact filler comes first. A statement about a whole AWS class comes after it: a class covers dozens of alloys, so it is the weaker of the two, and the corpus never turns one into the other.

• does not wetBCu-1
  Schwartz states that it is essentially impossible to braze graphite with copper filler metal AWS BCu-1, because no wetting occurs.
  Conditions and source

  Book page 158, prose, in the passage that opens a new brazing technique for joining graphite to itself or to metals such as molybdenum, tungsten or copper. The sentence names no partner and no condition of atmosphere or temperature. The same passage goes on to say that an iron foil insert makes the joint possible, which is a different technique and is not recorded here. This entry was identified at lot COMPAT-2 and could not be written then, because the enumeration carried wets and not its opposite.

  [A]M. M. Schwartz, Brazing, 2nd edition, ASM International, 2003, chapter 4, Base Metals and Base-Metal Family Groups, DOI 10.1361/brse2003p063

  Chapter 4 of the second edition, book pages 63 to 162 in the copy read, which treats base metals family by family and states metallurgical reactions, atmosphere limits and filler selection guides. It is a handbook chapter, not a qualification record. The page of each statement is carried by the entry that uses it, never by this registry line.

• listedTiCuNi
  Ticuni is listed for brazing carbon to stainless steel, to copper, to nickel, to titanium and zirconium alloys, and to carbon itself.
  Conditions and source

  Book page 153, table 4.28, Selection guide to filler metals for brazing metal-ceramic joints, carbon row. Source Ref 9 264 as cited by Schwartz, selection guide not a qualification. The identification rests on the commercial name alone: table 4.27 of the same chapter gives Ticuni as 70 Ti, 15 Cu, 15 Ni, while the corpus entry ti-cu-ni carries no composition to compare. The carbon row is marked with note (b), Includes alloys, while only note (c), Graphite and diamond, says what carbon means in this table. The corpus reads the carbon row under note (c) and records here that the document itself carries the other marker. The table does not list Ticuni against carbon and low-alloy steel, nor against refractory metals or tungsten carbide, where it lists Ticusil alone.

  [A]M. M. Schwartz, Brazing, 2nd edition, ASM International, 2003, chapter 4, Base Metals and Base-Metal Family Groups, DOI 10.1361/brse2003p063

  Chapter 4 of the second edition, book pages 63 to 162 in the copy read, which treats base metals family by family and states metallurgical reactions, atmosphere limits and filler selection guides. It is a handbook chapter, not a qualification record. The page of each statement is carried by the entry that uses it, never by this registry line.

• listedTicusil
  Ticusil is listed for brazing carbon to stainless steel, to copper, to nickel, to titanium and zirconium alloys, and to carbon itself.
  Conditions and source

  Book page 153, table 4.28, Selection guide to filler metals for brazing metal-ceramic joints, carbon row. Source Ref 9 264 as cited by Schwartz, selection guide not a qualification. Table 4.27 of the same chapter gives Ticusil as 68.8 Ag, 26.7 Cu, 4.5 Ti, which matches the corpus entry. The carbon row is marked with note (b), Includes alloys, while only note (c), Graphite and diamond, says what carbon means in this table. The corpus reads the carbon row under note (c) and records here that the document itself carries the other marker. The same row also lists Ticusil against carbon and low-alloy steel, tool steel, nickel and cobalt alloys, refractory metals and tungsten carbide, five families the corpus does not carry under an identifier, and those cells are not written.

  [A]M. M. Schwartz, Brazing, 2nd edition, ASM International, 2003, chapter 4, Base Metals and Base-Metal Family Groups, DOI 10.1361/brse2003p063

  Chapter 4 of the second edition, book pages 63 to 162 in the copy read, which treats base metals family by family and states metallurgical reactions, atmosphere limits and filler selection guides. It is a handbook chapter, not a qualification record. The page of each statement is carried by the entry that uses it, never by this registry line.

Chemical affinity

What documents state about a BINARY SYSTEM, one element of a filler metal faced with one element of this material. An affinity is not a verdict on a joint: a joint brings many binaries together at once, some helpful and some harmful, and what follows is the list of those the corpus can name. The count below is not written anywhere. It falls out of the crossing of this material's elements with the composition of every filler the corpus holds, so it grows on its own the day a binary enters the corpus.

Elements of this material: C, from the chemical name.

Open in the brazing abacus →