Patent EP0231620A2 successfully refreshed from Google Patents.
EP0231620A2
Expired / Lapsed
EP
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Permanent magnet manufacture from very low coercivity crystalline rare earth-transition metal-boron alloy
Assignee: Motors Liquidation Co
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Filing: 1986-12-10
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Granted: —
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Expires: 2006-12-10
Abstract
Abstract A method is disclosed of hot-working an alloy, comprising a magnetically-soft, cast, crystalline material containing grains of RE₂TM₁₄B, and an RE metal-rich intergranular second phase, into anisotropic permanent magnet bodies.
Inventors
- 👤 Peter Vernia
- 👤 Robert Weir Lee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:58
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/06; B22D11/0605; B61; B61B; B61B13/00; B61B13/12; B22D11/0637; B22D11/068; B22D11/0685; B22D41/00; B22D41/14; B22D41/22; B22D41/28; B22D41/34; B25; B25C; B25C5/00; B25C5/02; B25C5/0285; B25C5/0292; B27; B27K; B27K3/00; B27K3/02; B27K3/0278; B27K3/0292; B27K3/08; B27K3/16; B27K3/22; B27K3/34; B27K3/52; B27K5/00; B27K5/001; B29; B29C; B29C48/00; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/305; B29C48/307; B32; B32B; B32B27/00; B32B27/30; B41; B41F; B41F13/00; B41F13/08; B41F13/10; B41F13/12; B41F13/14; B41F13/16; B60; B60B; B60B39/00; B60B39/003; B60B39/006; B60M; B60M3/00; B60M3/04; B60W; B60W10/00; B60W10/02; B60W10/04; B60W10/06; B60W10/10; B60W10/11; B60W30/00; B60W30/18; B61B13/08; B65; B65B; B65B55/00; B65B55/02; B65B55/022; B65B7/00; B65B7/02; B65D; B65D33/00; B65D33/16; B65D75/00; B65D75/52; B65D75/58; B65D75/5861; B65D75/5872; B65D75/5877; B65D83/00; B65D83/14; B65D83/70; B65G; B65G47/00; B65G47/52; B65G47/60; B65G47/61; C; C01; C01B; C01B25/00; C01B25/003; C01B25/02; C01B25/027; C01B25/16; C01B25/18; C01B25/20; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/14; C01F7/144; C01F7/147; C11; C11B; C11B7/00; C11B7/0075; C21; C21D; C21D8/00; C21D8/12; C21D8/1216; C21D8/1222; F; F16; F16H; F16H61/00; F16H61/12; F16K; F16K17/00; F16K17/02; F16K17/14; F16K17/16; F16K17/162; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/057; H01F1/0571; H01F1/0575; H01F1/0576; H01F1/06; H01F1/068; H01F41/00; H01F41/02; H01F41/0253; H01G; H01G9/00; H01G9/004; H01G9/08; H01G9/12; H01M; H01M50/00; H01M50/30; H01M50/342; H01M50/3425; B27K2240/00; B27K2240/30; B29C48/03; B29C48/07; B29C48/08; B29K; B29K2033/00; B29K2055/00; B29K2055/02; B29L; B29L2031/00; B29L2031/769; B29L2031/7692; B60W50/00; B60W50/02; B60W50/0205; B60W2050/021; B60W2510/00; B60W2510/06; B60W2510/0638; B60W2510/10; B60W2510/1015; B60W2510/102; B60W2510/104; B60W2540/00; B60W2540/12; C01P; C01P2004/00; C01P2004/50; C01P2004/60; C01P2004/61; C21D8/1205; C21D8/1211; F16H2061/1208; F16H2061/122; F16H2061/1256; F16H2061/1284; F16H59/00; F16H59/36; F16H59/38; F16H59/40; F16H59/42; Y; Y02; Y02E; Y02E50/00; Y02E50/30; Y02E60/00; Y02E60/10; Y10; Y10S; Y10S101/00; Y10S101/36; Y10S477/00; Y10S477/906; Y10T; Y10T428/00; Y10T428/4935; Y10T428/662
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
152 words
A method of processing an alloy containing rare earth elements, iron and boron to make a permanent magnet, the method comprising hot-working the alloy at an elevated temperature and pressure to produce a final body which is magnetically anisotropic and exhibits permanent magnetic properties, characterised in that the alloy comprises a crystalline material consisting essentially of grains of RE₂TM₁₄B where RE is one or more rare earth elements, at least 60 percent of which is neodymium and/or praseodymium, TM is a transition metal, at least 60 percent of which is iron, and B is the element boron, which grains are separated by an intergranular layer of an alloy phase which is richer in rare earth elements than are the grains of RE₂TM₁₄B, the crystalline material initially having a coercivity of no more than 500 Oe, and said hot-working being carried out until the alloy acquires a coercivity in excess of l000 Oe.
Claim 2
Independent Claim
152 words
A method of processing an alloy containing rare earth elements, iron and boron to make a permanent magnet, the method comprising hot-working the alloy at an elevated temperature and pressure to produce a final body which is magnetically anisotropic and exhibits permanent magnetic properties, characterised in that the alloy comprises a crystalline material consisting essentially of grains of RE₂TM₁₄B where RE is one or more rare earth elements, at least 60 percent of which is neodymium and/or praseodymium, TM is a transition metal, at least 60 percent of which is iron, and B is the element boron, which grains are separated by an intergranular layer of an alloy phase which is richer in rare earth elements than are the grains of RE₂TM₁₄B, the crystalline material initially having a coercivity of no more than 500 Oe, and said hot-working being carried out until the alloy acquires a coercivity in excess of l000 Oe.
Claim 3
Independent Claim
25 words
A method of processing an alloy according to Claim l, characterised in that the grains of RE₂TM₁₄B are in the form of thin, flat platelets.
Claim 4
Independent Claim
29 words
A method of producing an alloy according to Claim l or 2, characterised in that said grains of RE₂TM₁₄B measure at least 5 micrometres along their smallest average dimension.
Claim 5
Independent Claim
135 words
A method of processing an alloy according to Claim l or 2, characterised in that the method comprises chill-casting a molten metal mixture (2,2′) containing rare earth elements, iron and boron in suitable proportions to form a solidified, magnetically-soft alloy (6,6′) having a predominant phase consisting essentially of said grains of RE₂TM₁₄B, said grains each having a crystallographic c-axis and being aggregated in regions where such axes are substantially parallel to one another, said alloy phase is a minor second phase which has a lower melting point than the RE₂TM₁₄B phase, said alloy (6,6′) is heated to an elevated temperature above the melting point of the second phase, and then said alloy is mechanically worked and deformed so that, upon cooling the alloy, the resulting body (20,85) is magnetically anisotropic and has permanent magnet characteristics.
Claim 6
Dependent Claim
177 words
A method of processing an alloy according to Claim 2, characterised in that the method comprises chill-casting a molten metal mixture (2) containing rare earth elements, iron and boron in suitable proportions to form a solidified, magnetically-soft alloy (6) having a predominant phase consisting essentially of flat platelets (8) of RE₂TM₁₄B, said platelets each having a crystallographic c-axis lying perpendicular to the flat faces thereof, and being aggregated in regions where the respective crystallographic c-axes are substantially parallel to one another, said alloy phase is a minor second phase between the platelets (8), which phase is relatively richer in rare earth elements than is the RE₂TM₁₄B phase, said alloy is attrited to form coarse particles (l2) which are greater than 50 micrometres in size, said particles (l2) are enclosed in a malleable metal container (l4,l6), said container (l4,l6) and alloy (6) are heated to an elevated temperature to melt the second phase, and said container (l4,l6) is rolled to deform it to such an extent that the particles (l2) therein are compacted to near l00 percent density.
Claim 7
Dependent Claim
147 words
A method of processing an alloy according to Claim 2, characterised in that the method comprises directionally-solidifying a molten metal mixture (2′) containing rare earth elements, iron and boron in suitable proportions to form a solidified, low-coercivity alloy (6′) having a predominant phase consisting essentially of said flat platelets (8′) of RE₂TM₁₄B, said platelets (8′) each having a crystallographic c-axis lying perpendicular to the flat faces thereof, said alloy phase is a minor phase between said platelets (8′), which minor phase is relatively richer in rare earth elements than is the RE₂TM₁₄B phase, said alloy (6′) is heated to an elevated temperature to melt the second phase, and said alloy (6′) is mechanically worked until it flows so as to align the crystallographic c-axes of the platelets (8′) therein, the body (85) resulting upon cooling of the hot-worked alloy being magnetically anisotropic and having permanent magnet characteristics.
References Cited (Backward Citations)
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