| 摘要 |
1,252,588. Magnetic compositions. GENERAL ELECTRIC CO. 5 Nov., 1968 [18 Dec., 1967], No. 52393/68. Heading H1N. [Also in Division C7] A magnet comprises Sb-coated single magnetic domain particles of Fe or Fe-Co alloy in a Pb matrix which contains (per part by wt. of Pb) 0À001-0À04 parts by wt. of Ca or a Snbased alloy, or 0À001-0À02 parts by wt. of Sn. Specified Sn-base alloys are 14À3% Cu, balance Sn; 6À5% Bi, balance Sn, and In or Te-containing alloys. The magnet may be made by electrolytically depositing magnetic particles into a liquid Hg cathode, heat-aging, adding Pb and Sb, followed by the Sn, Ca or Sn alloy, separating the cathode, e.g. by vacuum distillation, and compressing the residue. The mixture of Hg, Pb, Sb-coated particles and additive may be heated to ensure uniform dispersion of the additive, which inhibits dimensional instability and whisker growth in the finished magnet. In an example, the mixture is compressed in presence of a magnetic field to align the magnetic particles, and to reduce the Hg content. Remaining Hg is distilled from the preforms, which are then ground, classified and compressed with a lubricant. |
