EP0320064A1
Expired / Lapsed
EP
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Hard magnetic material of a rare earth metal, iron and carbon
Assignee: Koninklijke Philips NV
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Filing: 1988-12-05
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Granted: —
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Expires: 2008-12-05
Abstract
Abstract A hard magnetic material having the substantially stoichiometric composition Nd2Fe14C. It can be obtained by casting and subsequently recrystallization annealing at a temperature between 840 and 890 DEG C. A part of Fe may be substituted by Co. In this case the magnetic material is obtained by casting and subsequently recrystallization annealing at a temperature of approximately 850 DEG C.
Inventors
- 👤 Dirk Bastiaan De Mooij
- 👤 Kurt Heinz Jürgen Buschow
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:22
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/058
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
43 words
A hard magnetic material comprising a rare earth metal, iron and carbon, characterized in that the material consists of a recrystallization annealed cast material having a tetragonal crystal structure and a composition which does not or hardly deviate from the stoichiometric composition Nd₂Fe₁₄C.
Claim 2
Dependent Claim
43 words
A hard magnetic material comprising a rare earth metal, iron and carbon, characterized in that the material consists of a recrystallization annealed cast material having a tetragonal crystal structure and a composition which does not or hardly deviate from the stoichiometric composition Nd₂Fe₁₄C.
Claim 3
Dependent Claim
36 words
A hard magnetic material as claimed in Claim 1, characterized in that a maximum of 6 at.% of the Fe present in the hard magnetic material, calculated on the overall composition, has been substituted by Co.
Claim 4
Dependent Claim
40 words
A hard magnetic material as claimed in Claim 1, characterized in that as regards neodymium and carbon the composition's positive deviation from the stoichiometric composition does not exceed 20%, and as regards iron the positive deviation does not exceed 15%.
Claim 5
Dependent Claim
42 words
A hard magnetic material as claimed in Claim 3, characterized in that as regards Nd and C the composition's positive deviation from the stoichiometric composition does not exceed 20%, and as regards iron and cobalt the positive deviation does not exceed 15%.
Claim 6
Dependent Claim
26 words
A hard magnetic material as claimed in Claim 3, characterized in that the lattice constants amount to A = 8.814 Å and C = 12.015 Å.
Claim 7
Independent Claim
57 words
A method of manufacturing a hard magnetic material comprising neodymium, iron and carbon, characterized in that the starting materials neodymium, ion and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe₁₄C, and cast in a mould, after which the casting is recrystallization annealed at a temperature between 840 and 890° C.
Claim 8
Independent Claim
57 words
A method of manufacturing a hard magnetic material comprising neodymium, iron and carbon, characterized in that the starting materials neodymium, ion and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe₁₄C, and cast in a mould, after which the casting is recrystallization annealed at a temperature between 840 and 890° C.
Claim 9
Dependent Claim
22 words
A method as claimed in Claim 6, characterized in that the material is annealed at a temperature between 850 and 880° C.
Claim 10
Independent Claim
66 words
A method of manufacturing a hard magnetic material comprising neodymium, iron, cobalt and carbon, characterized in that the starting materials neodymium, iron, cobalt and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe 14-x Co x C (wherein x < 1.02) and cast in a mould, after which the casting is recrystallization annealed at a temperature of approximately 850° C.
Claim 11
Independent Claim
66 words
A method of manufacturing a hard magnetic material comprising neodymium, iron, cobalt and carbon, characterized in that the starting materials neodymium, iron, cobalt and carbon are melted together in a quantity which deviates little from the stoichiometric ratio Nd₂Fe 14-x Co x C (wherein x < 1.02) and cast in a mould, after which the casting is recrystallization annealed at a temperature of approximately 850° C.
Claim 12
Dependent Claim
41 words
Magnetic castings comprising a hard magnetic material as claimed in anyone of the Claims 1 upto and including 5, and/or magnetic castings obtained by means of a method as claimed in anyone of the Claims 6 up to and including 8.
References Cited (Backward Citations)
No citation records indexed.
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