| 摘要 |
1,184,118. Cu alloys and oxidation thereof. OLIN MATHIESON CHEMICAL CORP. Sept. 26, 1967 [Oct, 4, 1966], No.43695/67. Headings C7A and C7U. A Cu-base alloy consisting, apart from impurities, of (1) Cu, (2) 0À01-0À5% (by weight) of P, As, Sb and/or Bi, (3) 2-25% in total of two elements, with the ratio of the first to the second of said elements being 0À03: 1 to 10:1, the first element being Al, Ga, In or Be and the second element being Si, Ge, Sn or Be (for Be as the second element, Al must be the first), (4) optionally 0À05-5% of Co, Ce and/or Fe, and (5) optionally B, Mn, Zn, Cd and Be (if the latter is not already included), is made resistant to oxidation by heating it in an oxidizing environment (e.g. air, oxygen or molten NaNO 3 ) for at least 1 minute at 180‹-850‹C. At temperatures up to 400‹C., a layer 25-5000 Angstroms thick is formed, said layer consisting of an outer stratum rich in copper oxides and an inner stratum rich in oxides of said first element. At temperatures of 400‹ - 850‹ C. a second layer at least 50 Angstroms thick is formed beneath the two-stratum layer, said second layer containing a discrete dispersion of a complex oxide including at least one of the said first and second elements. The outer stratum is generally coloured, provides little or no oxidation resistance and is therefore preferably removed e.g. by dissolution in dilute H 2 SO 4 . If subsequently the inner stratum is removed, as by buffing, etching, pickling or mechanical forming, continued protection is afforded by the second layer. |
