Abstract: A method for controlling the remanance of a sintered magnet by varying the time when the orienting field is applied during cold compression. The method comprises obtaining powders of an appropriate particle size, compressing the powders in an oriented field, sintering, heat treating, machining and magnetizing to technical saturation. The cold compressing in an orienting field takes place at a precompression rate of more than 15% before the orienting field is applied. The method applies to magnets of all shapes which must have magnetic induction well defined in modulus and in direction, particularly annular magnets for traveling wave tubes.

Abstract: The invention relates to a method of obtaining friable and relatively inert TR Fe B type magnetic materials in divided form which lead to magnets having improved corrosion resistance. This method involves treating the material in an atmosphere containing (or capable of containing) hydrogen under the following conditions of absolute pressure (P) and of temperature (T.degree. C.): if P.ltoreq.Pa, 250<T<550; and if P>Pa, 250+100 log (P/Pa)<T<250+100 log (P/Pa) log base 10, Pa being atmospheric pressure. The invention is used for obtaining sintered TR Fe B magnets having improved corrosion resistance.

Abstract: The invention relates to Fe Nd B type alloys for permanent magnets, the permanent magnets thus obtained and a method of producing them.They have high magnetic characteristics with good temperature resistance and good resistance to atmospheric corrosion.They comprise, in at%, 12 to 18% of rare earths, 3 to 30% of Co, 5.9 to 12% of B, 2 to 10% of V, some Al and Cu, the remainder being iron and unavoidable impurities. The V can be substituted by other refractory elements (Nb, W, Cr, Mo, Ti, Zr, Hf, Ta).The method mainly involves sintering at between 1050 and 1110.degree. C. followed by annealing at between 850 and 1050.degree. C. and/or artificial ageing at between 560.degree. C. and 850.degree. C.

Abstract: A process and apparatus for permitting the magnetization of materials in the form of sheets or strips, such as magnetic rubber, wherein one or two stacks formed by flat main magnets 1 adjacent to ferromagnetic pole pieces 2 in the vicinity of which (or between which) travels the strip to be magnetized. The main magnets adjacent to the same pole piece having opposing magnetizations as well as the magnets located face to face in each of the stacks. The device can be completed by field magnets .delta. and intermediate magnets 9.

Abstract: The invention relates to a process for preparing ferrite powders of Ba, Sr, and/or Pb intended to be incorporated in an elastomeric, thermoplastic, or thermosettable binder for manufacturing flexible or rigid permanent magnets. The process comprises the preparation of a mixture of iron oxides and carbonates of Ba, Sr and/or Pb, adding to said mixture one or more alkaline earth halides in a total proportion of 0.5 to 15% of the total weight of the mixture, and one or more oxygenated boron compounds, more particularly, alkaline and/or alkaline earth borates, in a proportion of 0.2 to 7%, and calcining said mixture between 850.degree. and 1100.degree. C. for at least 15 minutes.

Abstract: The invention relates to a process for preparing ferrite powders of Ba, Sr, and/or Pb intended to be incorporated in an elastomeric, thermoplastic, or thermosettable binder for manufacturing flexible or rigid permanent magnets.The process consists of starting out with a mixture of.alpha. Fe.sub.2 O.sub.3 iron oxides and carbonates of Ba, Sr and/or Pb, adding to said mixture one or more alkaline and/or alkaline earth halides in a total proportion of 0.5 to 15% of the total weight of the mixture, and one or more oxygenated boron compounds, more particularly, alkaline and/or alkaline earth borates, in a proportion of 0.2 to 7%, and calcining said mixture between 850.degree. and 1100.degree. C. for at least 15 minutes.

Abstract: A process for the thermal treatment of an Fe-Co-Cr alloy for a permanent magnet, constituted by weight of 10 to 40% of Cr, from 0 to 10% of one or more elements of the group Al, Nb, Ta, W, Mo, V, Ti, Si and Cu, the remainder being iron. The process comprises homogenization treatment at between 1200.degree. and 1400.degree. C., an annealing treatment and one or more tempering treatments at between 500.degree. and 600.degree. C.; the annealing treatment comprises two stages, the first at between 630.degree. and 670.degree. for 5 to 30 minutes, the second, without a return to ambient temperature, at a temperature of from 40.degree. to 70.degree. C. below the previous stage for at least 10 minutes.Isotropic or anisotropic magnets whose hysteresis curve exhibits a better rectangular shape are thus obtained.

Abstract: The present invention relates to a composition for permanent magnets of the family "rare earths-transition metals" wherein in a structure of the SmCo.sub.5 type, 2 to 15% of the cobalt atoms are replaced by nickel.This can be applied to the production by the sintered powder technique of permanent magnets having a particularly high intrinsic coercivity.