Abstract: A method for making ferrite magnets of formula M1-xRxFe12-yTyO19 including: a1) forming a powder mixture MP of related raw materials, a2) transforming into granules in green state A, b) calcining the granules in green state to form clinker B, c) wet ding clinker B to obtain a homogeneous dispersion of fine particles C, d) concentrating and compressing the particles under an orienting magnetic field to form an anisotropic green compact D, and e) sintering the green compact to obtain a sintered element E. In step a1), MP is formed from a dry mixture MS of M and Fe powder elements and a dispersion DF of raw materials related to elements R and T, and in step b) the granules in green state are calcined to obtain a clinker B which is homogeneous in chemical composition and size and with apparent low density, between 2.5 and 3.5.

Abstract: A method for manufacturing type M hexaferrite powders fo the formula AFe12O19 where A is Ba, Sr, Ca, Pb or a mixture thereof. An iron oxide Fe2O3 and a compound A are mixed with a molar ratio n=Fe2O3/AO, formed and calcined, and the agglomerates which result from the calcining are ground to obtain a fine ferrite powder. The mixture is formed with a ratio n ranging between 5.7 and 6.1, and with a predetermined degree of homogeneity, and before or during the grinding process, an agent controlling the microstructure is introduced.

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: 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.