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    Passivated, particulate high Curie temperature magnetic alloys
    1.
    发明授权
    Passivated, particulate high Curie temperature magnetic alloys 失效
    钝化，微粒高居里温度磁性合金

    公开(公告)号：US4229234A

    公开(公告)日：1980-10-21

    申请号：US384

    申请日：1978-12-29

    申请人： Richard C. Krutenat ,  Chih-an Liu

    发明人： Richard C. Krutenat ,  Chih-an Liu

    IPC分类号： C22C19/00 ,  B01J8/42 ,  B01J23/74 ,  B01J23/76 ,  B01J23/86 ,  B01J33/00 ,  B01J35/08 ,  B01J37/14 ,  C22C38/00 ,  H01F1/06

    CPC分类号： H01F1/061 ,  B01J23/74 ,  B01J23/86

    摘要： A process, and the compositions produced thereby, wherein an element characterized as aluminum, silicon or chromium, notably aluminum, is alloyed in relatively small concentrations with iron, cobalt or nickel, notably iron or cobalt, or both, which have relatively high Curie temperatures. Small amounts of yttrium, hafnium, zirconium or lanthanium can also be added. Alloys of specified composition are formed into particles of selected size, and the particles then contacted in an atmosphere of controlled oxygen activity at elevated temperature over selected time periods. By treatment with a low oxygen-containing, or low moisture-containing gas an oxide of the alloying element is formed which diffuses to the surface of the particles to form a film. The addition of these elements to the base metal necessarily, and unavoidably reduces the Curie temperature of the metal. However, by limiting the particle size and the amount of oxidation of the alloys, a relatively thin impervious oxide film can be formed on the surface of the alloy particle, and much of the lost Curie temperature can be recovered by the increased magnetization which occurs at the particle core when the oxidized form of the metal migrates, or diffuses, to the surface of the particle.

    摘要翻译： 一种方法和由此制备的组合物，其中以铝，硅或铬（特别是铝）为特征的元素以相对较小的浓度与铁，钴或镍，特别是铁或钴或两者合金化，其具有相对较高的居里温度 。 也可以加入少量的钇，铪，锆或镧。 指定组合物的合金形成为选定尺寸的颗粒，然后颗粒在选定的时间段内在升高的温度下在受控氧活性的气氛中接触。 通过用低含氧气体或低含水气体处理，形成合金元素的氧化物，其扩散到颗粒的表面以形成膜。 必须将这些元素添加到母体金属中，并且不可避免地降低金属的居里温度。 然而，通过限制合金的粒径和氧化量，可以在合金颗粒的表面上形成相对薄的不可渗透的氧化物膜，并且通过增加的磁化强度可以恢复大部分损失的居里温度 当氧化形式的金属迁移或扩散到颗粒表面时，颗粒核心。