| 摘要 |
1,141,754. Making lead/lead oxide particles; dispersion strengthened lead; modifying lead surfaces. ASSOCIATED LEAD MFRS. Ltd and ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Jan.26,1967 [Feb.10,1966; March 25,1966; March 28,1966], No.4022/67. Headings C7A, C7D, C7U and C7X. Pb particles which have Pb oxide coatings and are substantially free from carbonate groups are made by subjecting lead particles, either solid or molten, to the action of an acid-forming oxide of S, in the substantial absence of free or combined CO 2 , during or subsequent to the formation of coatings of Pb oxide on the particles. The particles may be plastically deformed, as by compaction and extrusion or by rolling, to make dispersionstrenghthened Pb. The Pb used may be pure, or may contain minor amounts, e. g. up to 0À25% by weight, of Sb, Cu, Te or Ag and the particles made may contain up to 16% by weight of PbO. Molten Pb may be atomized in an atmosphere containing e. g. SO 2 or SO 3 and O 2 , preferably with a molar ratio of O 2 to S oxide of 5-50 and at above 25‹C. Alternatively Pb particles which have been made with Pb oxide coatings, e.g. by atomizing molten Pb in an oxidizing atmosphere such as air or by stirring Pb particles in air in the presence of moisture, may be heated to between 280‹C, and the melting points of Pb, then be treated with the S oxide at 100-350‹C. |
