Silicon carbide-to-metal joint and method of making same

{
  "publication_number": "US4610934A",
  "country": "US",
  "kind": "A",
  "title": "Silicon carbide-to-metal joint and method of making same",
  "abstract": "A silicon carbide-to-metal joint includes a thin layer of metal adherent to the ceramic material, a compliant layer of metal overlying the thin metal layer and a brazing alloy in contact with the metal to which the ceramic material is joined. A method for preparing a silicon carbide surface for joining by metallic brazing to a metal includes the steps of applying a thin layer of metal adherent to the ceramic surface followed by application of a compliant layer of metal. Also described is an easily brazable silicon carbide article which includes a silicon carbide substrate, a thin electrically conductive adherent metal layer overlying the substrate and a compliant metal layer overlying the thin metal layer.",
  "claims": [
    "1. A silicon carbide article which may be easily brazed to a metal article, the silicon carbide article comprising a silicon carbide substrate having a thin highly adherent layer of metal selected from the group consisting of Ni, Cr, Au, Ag or Cu applied to a surface thereof.",
    "2. The silicon carbide article of claim 1 wherein said thin adherent layer is electrolessly deposited Ni having a thickness of less than 0.0005 inch.",
    "3. The silicon carbide article of claim 2 further comprising a compliant layer of metal overlying said thin Ni layer, said compliant layer metal selected from the group consisting of Cu, Ag, Au, Pt and brass, said compliant layer having a thickness of from about 0.002 to about 0.004 inch.",
    "4. The silicon carbide article of claim 3 wherein the compliant layer metal is electroplated Cu.",
    "5. The silicon carbide article of claim 4 wherein a layer of Ni overlies the Cu layer.",
    "6. A silicon carbide-to-metal joint comprising: (a) a silicon carbide article according to claim 1; (b) a metal article; (c) a compliant layer of metal overlying and adherent to said thin highly adherent metal layer; and (d) a brazing layer overlying said compliant layer and joining said silicon carbide article to said metal article wherein said compliant layer and said brazing layer are different layers.",
    "7. The joint of claim 6 wherein the thin adherent layer is Ni having a thickness less than 0.0005 inch; the compliant layer is Cu having a thickness of from about 0.002 to about 0.004 inch and the brazing layer is of a metal or metal alloy having a melting point below that of the Ni or Cu layers.",
    "8. A silicon carbide-to-metal joint comprising: (a) a silicon carbide article according to claim 1; (b) a metal article; (c) a compliant layer of metal overlying and adherent to said thin highly adherent metal layer wherein said compliant layer also functions as a brazing layer joining said silicon carbide article to said metal article.",
    "9. The joint of claim 8 wherein the thin adherent layer is nickel having a thickness less than 0.0005 inch; and the compliant layer is copper having a thickness of from about 0.002 to about 0.004 inch."
  ],
  "description_excerpt": "This invention relates to an easily brazable ceramic article, a method for preparing a ceramic surface for joining by metal brazing to a metal and a brazed ceramic-to-metal joint. More particularly, this invention relates to silicon carbide structural ceramic articles which are easily brazable and methods for preparing same and brazed joints between such articles and metals.\n\nAs used herein, the term \"silicon carbide\" includes any silicon carbide-based structural ceramic material including composite materials.\n\nStructural silicon carbide articles have recently become of high interest as replacements for articles of metal and metallic alloys in structural applications such as engine components where a combination of strength, temperature resistance, oxidation resistance, hardness, wear resistance and low specific gravity are desired. However, known structural silicon carbide materials are not a panacea in all applications due to high cost, difficulty of fabrication, low rupture resistance and low mechanical impact resistance compared to metals and metallic alloys, particularly at lower operating temperatures. Thus, pragmatically, requirements of many applications would be best filled by use of articles having portions made of a silicon carbide and other portions made of metal or metallic alloy. These portions could be joined by brazing. However, structural silicon carbide andd metals exhibit dissimilar physical properties which make known brazing techniques of little use.",
  "cpc": [
    "C04B 41/009",
    "C04B 2237/12",
    "C04B 2237/122",
    "C04B 2237/123",
    "C04B 2237/124",
    "C04B 2237/125",
    "C04B 2237/365",
    "C04B 2237/406",
    "C04B 2237/52",
    "C04B 2237/708",
    "C04B 2237/72",
    "C04B 2237/84",
    "C04B 37/026",
    "C04B 41/52",
    "C04B 41/89",
    "Y10S 228/903",
    "Y10T 428/12576"
  ],
  "ipc": [
    "C04B 37/02",
    "C04B 41/52",
    "C04B 41/89"
  ],
  "assignees": [
    "Kennecott Corp"
  ],
  "inventors": [
    "Wolfgang D. G. Boecker",
    "Laurence N. Hailey"
  ],
  "filing_date": "1985-01-17",
  "publication_date": "1986-09-09",
  "grant_date": "1986-09-09",
  "priority_date": "1985-01-17",
  "application_number": "US-69294485-A",
  "family_id": "24782692",
  "cited_by_count": 60,
  "citations": [
    "US3279042A",
    "US4075364A",
    "US4517217A",
    "US4532190A"
  ]
}