DE2121596C3 - Use of an alloy as a hard magnetic material - Google Patents

Description

The high magnetic crystal anisotropy of the ten earth metals to semi-magnetic alloys SECo ₆ alloys is largely determined by the non-composition SECo ₅ with an energy-procubic crystal structure, whereby the madukt of more than 10 ⁷ G · To process Oe, the rare earth metal's price would not be of crucial importance due to the relatively high 5, because YCu ₅ , in the cerium mischmetal and cobalt price for many yttrium core, also has hard magnetic conventional moment Applications of hard magnetic mate is. It should also be taken into account that iron is too high in the verrialien. In addition, SECo _s -alloy has a higher moment than cobalt, for example the Curie temperature, the saturation - that, if it is possible to incorporate iron into the hard magnetic magnetization, the coercive field strength etc., hardly any phases, all other things being equal, targeting the special requirements of hard magnet! For this reason, such alloys have been produced and investigated in optical storage or in other data in which the rare earth carriers can be adapted. metals partially or entirely by elements or The object of the invention is therefore to replace 15 mixtures of elements with comparable atomic hard magnetic alloys with a sufficiently large radius or while approximately maintaining the Va saturation magnetization, coercive field strength and bilge electron concentration. Further to develop energy product in which the pure alloys were manufactured in which cobalt pre-rare earth metals as well as the cobalt are partially or preferably replaced by some other 3d metals, especially completely by other elements. »O iron has been partially or wholly replaced, whereby the laid-open specification 19 15 358 is a magnetic material stabilizing non-cubic crystal structures with a component (A) which, if necessary, by further addition of not at least one consisting of cobalt and iron Transition metals, has been studied in detail,
This series of tests surprisingly showed a component (RE), which has at least one of the "5 that numerous alloys have hard magnetic properties from samarium, cerium, gadolinium, praseodymium, lanthanum, if on the one hand partly yttrium, Neodymium and holmium existing group or complete replacement of rare earth metals is known, with the identification magnesium and / or calcium and on the other hand in addition to drawing that the material is also a grain or instead of cobalt chromium and / or component (B), which are alloyed from the group Si, Sn, consisting of iron, optionally with the admixture of Zn, Al, copper, nickel and aluminum, provided that at least one of the selected elements is that the material has the general speaking phases has a non-cubic crystal structure formula (AB) ₁ (RE), where χ has between door.

5 and about 8.5, and that the composition The advantages of the invention to be used

within a range in a ternary dia- 35 the alloys exemplified below

gram, which is explained by the between the following, consist mainly in the following

Points drawn lines is limited: possibilities, namely a) also iron, which is a very

a \ 18 «/ A has a high magnetic moment, into a non-

71 5 β / Β cubic, hard magnetic alloy to be incorporated;

'_ _{0 /} °, _p. 40 b) alloys with variable, the respective

, 5, 0 (KIi; purpose-adapted Curie temperature and

b) to produce 16.7 "Vo A coercive force; c) alloys with

66.6 ° / o B high energy product and d) metals

16.7 ° / o (RE) with low price (iron, magnesium, cobalt, etc.)

45 to be used in hard plastic materials of high quality

c) 81.6 ° / o A work and so numerous new fields of application

1.7%> B for hard magnetic materials to be developed.

16.7% (RE) As can be seen from the example, alloy

d) 87 7 ° / o A rang with high maximum energy product and

18% B prepared ⁵ ° h ° ^ner saturation magnetization,

10 * 5 ° / o (RE) ^ ^e none ° d ^{er only} a small proportion of rare species

'Contain earth metals, or instead of cobalt

It is also from the laid-open specification 19 54 698 iron as a carrier of the magnetic moment aufwei-

a cast permanent magnet made of a mixed crystal sen, if certain conditions with regard to the

with a composition Co _5-1 A _x R, in which A Cu 55 atomic radii, the valence electron number and the elec-

is that are fully or partially satisfied by Al, Ni and some tronegativity. These alloys know

other elements can be replaced, in which R an iron is essentially a non-cubic one

ment or more rare earth elements and crystal structure. The stability of these alloys

in which O < χ <4 is known, in which the stoichio- and the crystal structure is given by the fact that

metric ratio (Co + A): R = 5: (1 - d) with 60 magnesium and / or calcium and the elements AIu-

O ■ <(} ■ < Is 0.17. minium, silicon, zinc and / or tin in addition to chromium,

In contrast to this, iron and / or cobalt are present according to the invention.
Alloys to be used considerably larger Va alloys of the range described in the patent claims, in particular due to the recognized possible composition, were known from the patent to use magnesium and / or 65 6 28 306, but calcium for such purposes. Further technical advances resulted in dentures. From this, the use could be derived from the following considerations and investigations not based on them for the purpose according to the invention.

The manufacture of the materials or permanent magnets to be used according to the invention also by means of Verdenden alloys can be carried out with conventional melting and pressing, hot pressing, extrusion or by sin-sintering processes. As a starting material for tem These processes often promote the production of the alloys are normally used - in a known manner - the formation of directional, technically pure metals.
Preferably other rare earth metals as well as non- The melting of the alloys under elevated metals, such as hydrogen, oxygen, nitrogen, carbon pressure can therefore be advantageous to a Verlenstoff etc., as impurities. Instead of preventing vaporization of the alloy partners or rare earth metals are used for economic reasons, because higher pressures can often lead to the formation of crystal bases, mixtures of rare earth structures that have particularly high mametallic properties, e.g. B. "Didym" or Cermischmetall with magnetic crystal anisotropy and therefore used with particular advantage. Expediently, they often have high magnetic energy products;
Vorlegieruagen run out. If the starting materials or master alloys were either evaporated in a high-frequency furnace in. 15 in a vacuum, the ceramic crucibles according to the invention, alloys to be used in an electric arc furnace or in a thin-layer beam melting furnace can be manufactured on an industrial scale. Such hard magnetic Le melting in ceramic or metal crucibles under layers of alloy, possibly with a z. B. preferable to a salt cover. These processes are well known through a heat treatment or through the application of reactive metals technology, ao sheit a magnetic field achieved texture, are suitable. B. for magneto-optical storage purposes, for NEN when there are major differences in terms of magnetic data storage (e.g. magnetic sound carrier), melting point or boiling point, etc.

The various technical types of use are partially connected to the finished alloy by sintering. The already existing alloy 25 of hard magnetic alloys in the form of Perma is advantageously nentmagneten after appropriate comminution, e.g. B. further processed as cast or sintered by sintering to the finished product, or materials composed of fine particles; in if either a specific sample shape is sought the form of magnetic storage elements ζ. Β. as is or when through the sintering process ^ in a magnetic core memory or magneto-optical memory; Magnetic field at the same time a magnetic alignment 30 in the form of thin layers and finely divided is to be achieved. Shape are essentially known. The magnetic characteristics listed were determined in accordance with the alloys to be used and are therefore particularly suitable for these purposes from measurements of the remanence and the coercive field, strength on small test magnets. This test - because through a suitable composition (mixing magnets were produced by pressing the corresponding ratio between transition metals and non-alloy powder with organic binders transition metals or between rare earths. Usually the pressing was done in metals and magnesium or calcium) the specific magnetic field of about 10 kOe . The alloy cations of the alloys of the individual technical powders can be adapted to the melted Le requirements by grinding, which gives them alloys in a vibrating ball mill. 40 gives special technical progress.
All the technology of making the perma-.
nentmagnete from the example to be used according to the invention
the alloys closely follow the well-known approx. 25 g of an alloy of the composition technology of ferrites. Accordingly, Ca ₀₁₀ Fe _0. , 5Co ₀₁₁₀ Zn ₀₁₀ are made by mixing the in the permanent magnetic alloys z. B. finely ground in a ball mill under an argon protective gas atmosphere, pressed with or without a magnetic field and produced metal powder of technical purity (partly by suitable means, such as e.g. by sintering or particle size 20 to 40 μm) in the appropriate amount by binding agent, bonded to form solid bodies. ratio, subsequent pressing to tablets of These are brought into suitable shapes or about 25 g and sintered in a hot material stream at post-processed and produced by magnetizing at the temperature of 50,950 ° C. The same alloy can also be converted into a demagnetic state. The based on 2 master alloys with the composite properties of the alloys can be treated with Ca ₀₅ Zn _0-5 and Fe ₀₁₈₇₅ Co ₀₁₂₅ , which can also be changed by heat melting in the high-frequency furnace - Mixing of the master alloys can be produced beforehand, for example below the Curie temperature, with or 55 granulation and melting at 1300 ° C. in a pre-frequency furnace without the presence of a magnetic field. ! The predominant one is taken. Crystal structure is rhombic. On the basis of the magnetization of 11300 G to be used according to the invention and an energy product of the alloys, permanent magnetic dimensions of 3.1 · 10 ⁷ G · Oe are observed.

Claims (2)

The maximum possible energy product for patent claims · Alnico magnets is 1.0-10 »G-Oe, with ferrites 3.7-10« ratentanspnicne. q q & ^. Carbon steels about 1> 0.10, G. Q8 1. Use of an alloy of the general type and, for platinum-cobalt magnets, 9.2 × 10 · G · Oe.
Composition AJJ ₁ AD _{1 x} , “in which A 5 is recently a new class of perma-magnesium and calcium; B has been developed for the magnetic materials, which correspond to the rare earth metals, on alloys of the rare earth metals (SE) with C chromium, iron and cobalt and D aluminum, cobalt with the approximate composition SECo _s mean silicon, zinc and tin, where x = 0.05. The definition of the rare earth metals umbis 0.20, y = 0.0 to 0.25 and ζ = 0.40 to 0.85 io includes the elements scandium (atomic number, and always at least one of the elements in the alloy 21) , Yttrium (atomic number 39) and the phases contained in lanthanum have a non-cubic noiden (lanthanum, atomic number 57, to lutetium, crystal structure, as hard magnetic atomic number 71). Compounds with the composition SECo ₅ exist at least for SE = Y, La, 2. Use of an alloy composed of Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er. This reduction according to claim 1 with the proviso that bonds consistently have a structure before hexagonal CaCu ₅ - that the sum χ + y = 0.14 to 0.20. The SECo ₆ compounds of this Strukfür dea purpose according to claim 1. door is now almost always a high magnetic crystal anisotropy peculiar, so that the alloys in which ao SECOg phases are present, permanent magnetic see properties. Hence the Use of alloys of approximate composition SECo ₅ by U.S. Patent 3,424,578 The invention relates to the use of a Le protected. This patent also mentions the addition the general composition of manganese and / or iron to form cobalt claimed. Aj ₁ BX ₁ D _{1 x} " ,, In the journal Applied Physics Letters 16, 312/313 (1970), was about permanent magnetic where A denotes magnesium and calcium, B corresponds to the alloys consisting of rare earth metals, cobalt and elements of the rare earth metals, 30 copper, which sometimes also contains smaller iron components C chromium, iron and cobalt and D aluminum, SiIi, reports. These alloys consist of cium, zinc and tin, where χ - 0.05 obviously consists of precipitates from SECo ₅ -rich to 0.20, y = 0.0 to 0.25 and ζ = 0.40 to 0.85, Phases in a non-magnetic or soft magnetic matrix and always at least one in the alloy ent- trix. The carrier of the phases with permanent magnetic properties is a non-cubic crystal structure 35 th of the alloys mentioned is therefore always possessed as a hard magnetic material. It affects the SECo ₆ phase. the unspecified proportions of especially the use of an alloy, Cu, Mn and Fe built into the lattice, in which the sum χ + y = 0.14 to 0.20. It is important to note, however, that no magnetic Hard magnetic materials are, on the one hand, determined by table measurements on an unambiguously as pure SEFe ₅ - the presence of 4 »phase or z. B. as iron-rich SE (Fe, Co, Ni) ₅ -coupled magnetic moments, which are present below the phase identified alloy, although they are ordered at a certain temperature, identified by the existence of SEFe ₅ phases with the CaCu ₅ , so that a resulting overall magnetic structure is observed variously in literature reports, and on the other hand, by a, z. B. in the Zeitschrift für Metallkunde, 60, finite coercive field strength of the order of magnitude 45 pp. 778 to 784 (1969). moderately 100 to 10,000 Oe. Hard magnetic alloy from our own research shows that with rangen and compounds have been used for many years, common melting process SEFe ₅ compounds and in recent times are constantly finding new ones that cannot be produced in a single phase, so that applications can be assumed, such as, for. B. in permanent magnets, which is that the SEFe ₅ phases are not stable at room temperature and for the conversion of mechanical energy into electrical energy so normal pressure,
gie, and vice versa, are used in data processing among the permanent magnetic materials Up to now, systems in the form of SECo _s -based magnetic core storages have mainly achieved alloys with or magncio-optical storages, etc. The important samarium has gained technical importance. For the most favorable characteristics of hard magnetic materials, SmCo ₅ permanent magnets have been given an energy value of their saturation magnetization, measured in terms of a product of 2.0-10 ⁷ G-Oe. With PrCo ₅ -Gauss (G), as well as the so-called energy product magnets, an energy product of 10 ⁷ G · Oe (B · H) _max , measured in Gauss · Oersted (G · Oe). achieved. The current state of the art of manufacturing operating temperature, hard magnetic alloys and compound products usually show the greatest possible energy, while in applications hard- ⁶ ° the highest energy product is based on the vermagnetic materials in data processing compounds of the basic composition SECo ₅ , with systems often having a certain ratio of energy to the rare earth metal preferably samarium or product, coercive field strength and order temperature is praseodymium and the cobalt is necessary to a low level. Part by other 3d metals as well as by copper At present, magnetic 65 can be replaced as permanent. Such alloys are Materials technically mainly Alnico magnets, for several reasons only for individual special An-Ferrites, Carbon steel and platinum-cobalt magnets are suitable for turns. Both samarium and used. Praseodymium metal is extremely expensive. Even if it is