JPH02263415A - Manufacture of radial anisotropic permanent magnet - Google Patents
Manufacture of radial anisotropic permanent magnetInfo
- Publication number
- JPH02263415A JPH02263415A JP8498589A JP8498589A JPH02263415A JP H02263415 A JPH02263415 A JP H02263415A JP 8498589 A JP8498589 A JP 8498589A JP 8498589 A JP8498589 A JP 8498589A JP H02263415 A JPH02263415 A JP H02263415A
- Authority
- JP
- Japan
- Prior art keywords
- hot
- permanent magnet
- metal plate
- anisotropic permanent
- mold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000001125 extrusion Methods 0.000 claims abstract description 26
- 229910052742 iron Inorganic materials 0.000 claims abstract description 22
- 238000003825 pressing Methods 0.000 claims abstract description 19
- 238000000034 method Methods 0.000 claims abstract description 18
- 229910052751 metal Inorganic materials 0.000 claims description 35
- 239000002184 metal Substances 0.000 claims description 35
- 239000000843 powder Substances 0.000 claims description 21
- 238000001192 hot extrusion Methods 0.000 claims description 16
- 238000007731 hot pressing Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 13
- 239000006247 magnetic powder Substances 0.000 abstract description 12
- 238000000465 moulding Methods 0.000 abstract description 9
- 230000002093 peripheral effect Effects 0.000 abstract description 7
- 230000000694 effects Effects 0.000 abstract description 4
- 229910052761 rare earth metal Inorganic materials 0.000 abstract description 4
- 239000006185 dispersion Substances 0.000 abstract 2
- 150000001875 compounds Chemical class 0.000 abstract 1
- 238000005336 cracking Methods 0.000 abstract 1
- 239000007769 metal material Substances 0.000 abstract 1
- 150000002910 rare earth metals Chemical group 0.000 abstract 1
- 230000007704 transition Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 2
- 235000012438 extruded product Nutrition 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000828 alnico Inorganic materials 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Manufacturing Cores, Coils, And Magnets (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
（産業上の利用分野）
本発明は、ラジアル方向に異方性をもつ永久磁石を製造
するのに利用されるラジアル異方性永久磁石の製造方法
に関するものである。
（従来の技術）
近年、永久磁石として、従来のアルニコ系磁石や希土類
−コバルト系磁石に比べてさらに磁気特性の優れた希土
類−鉄系磁石が注目されるようになってきている。
この希土類−鉄系磁石は、Ｎｄ−Ｆｅ−Ｂ等のＲ−Ｔ−
Ｍ系のものであって、Ｒは希土類元素。
Ｔは鉄系の遷移元素９Ｍはその他の元素からなるもので
ある。
この種の希土類−鉄系磁石において、ラジアル方向に異
方性をもつ永久磁石を製造するに際しては、例えば、第
３図（ａ）〜（ｄ）に示す工程をとっていた。
すなわち、第３図（ｂ）に示すように、側部型２１と上
部型２２と下部型２３とからなる熱間成形型２４を用い
、第３図（ａ）に示すように、側部型２１と下部型２３
とで形成され成形空間２５内に、希土類−鉄系磁石粉末
２６を入れ、あるいは希土類−鉄系磁石粉末を冷間成形
した図示しない成形体を入れ、次いで、第３図（ｂ）に
示すように、上部型２２を降下させて前記希土類−鉄系
磁石粉末２６やこれの冷間成形体を熱間で加圧する熱間
成形（ホットプレス）を行い、次いで、第３図ＣＣ）に
示すように、側部型３１と上部型３２と下部型３３とか
らなる押出ダイス３４を用い、側部型３１と下部型３３
とで形成される成形空間３５内に、第３図（ｂ）の熱間
成形型２４で成形した熱間成形体２７を入れ、上部型３
２を降下させて後方押出しを行うことによって、８３図
（ｄ）に示すような形状の後方押出成形体３５を得るこ
とにより、ラジアル異方性永久磁石が製造されるように
していた。
（発明が解決しようとする課題）
しかしながら、このような従来のラジアル異方性永久磁
石の製造方法では、後方押出成形体３５の内周側に割れ
３６を生じやすく、磁気特性が良好である内周側を研磨
することとなるため、全体の磁気特性が低下するという
課題があった。
また、熱間成形型２４と押出しダイス３４とを用いてお
り、同一の成形型で熱間成形と後方押出しとを行うこと
ができないので、押出成形体３５に対して対称な歪を与
えることができず、周方向における磁気特性にばらつき
を生ずることがあるという課題があった。
（発明の目的）
本発明は、上述した従来の課題に着目してなされたもの
で、リング状部を有する押出成形体からなる永久磁石粗
材としたときでもリング状部分の内周面側に割れが発生
せず、したがって割れが発生した場合のように磁気特性
のすぐれた内周面を研磨して除去する必要がないため磁
気特性にすぐれたものとすることが可能であり、かつま
た熱間成形と押出成形とを同一の成形型で行うことによ
り押出成形体に対して対称な歪を与えることができ、周
方向における磁気特性のばらつきが少ないラジアル異方
性永久磁石を提供することが可能であるラジアル異方性
永久磁石の製造方法を提供することを目的としている。
〔発明の構成］
（課題を解決するための手段）
本発明の第１請求項に係るラジアル異方性永久磁石の製
造方法は、Ｒ−Ｔ−Ｍ （たゾし、Ｒは希土類元素のう
ちから選ばれる１種または２種以上、Ｔは鉄族の遷移元
素のうちから選ばれる１種または２種以上、Ｍは特性改
善元素のうちから選ばれる１種または２Ｍ以上）を主成
分とする希土類−鉄系磁石粉末を熱間兼押出成形型内に
入れると共に、前記磁石粉末の少なくとも加圧面側に金
属板材を配設して、前記金属板材側から前記磁石粉末を
熱間で加圧する熱間成形を行い、次いで前記金属板材側
からさらに押圧する押出成形を行って、リング状部分を
有するラジアル異方性永久磁石を得る構成とし１本発明
の第２請求項に係るラジアル異方性永久磁石の製造方法
は、上記Ｒ−Ｔ−Ｍを主成分とする希土類−鉄系磁石粉
末を冷間成形することにより得た冷間成形体を熱間兼押
出成形型内に入れると共に、前記冷間成形体の少なくと
も加圧面側に金属板材を配設して、前記金属板材側から
前記成形体を熱間で加圧する熱間成形を行い、次いで前
記金属板材側からさらに押圧する押出成形を行って、リ
ング状部分を有するラジアル異方性永久磁石を得る構成
としたことを特徴としており、これらの構成を前述した
従来の課題を解決するための手段としている。
本発明のラジアル異方性永久磁石の製造方法において適
用される永久磁石は、Ｒ−Ｔ−Ｍを主成分とする希土類
−鉄系のものであり、Ｒは高磁気特性が得られるＮｄ
、Ｐｒや、比較的低床なＣｅ、ミツシュメタルや、高保
磁力が得られるＤＹ 、Ｔｂなどの希土類元素のうちか
ら選ばれる１種または２種以上からなるものである。ま
たＴは鉄族の遷移元素であるＦｅ、Ｃｏ、Ｎｉや鉄族以
外の遷移元素であるＭｎなどのうちから選ばれる１種ま
たは２種以上からなるものである。さらに、ＭはＢ、Ｃ
，Ｐ、Ｓｉ等のうちから選ばれる１種または２種以上で
あり、また、このＭには、温度特性、保磁力、減磁曲線
の角形性、耐食性９機械加工性などを向上させるために
、Ｔｆ。
Ｚｒ、Ｈｆ、Ｖ、Ｎｂ、Ｔａ、Ｃｒ、Ｍｏ、Ｗ。
Ｒｕ、Ｒｈ、Ｐｄ、Ｏｓ、Ｉｒ、Ｐｔ、Ｃｕ。
Ｚｎ、Ａｌｌ、Ｇａ、Ｉｎ、Ｔｕ、Ｐｂ、Ｂｉ 。
Ｌｉ、Ｍｇ、Ｃａ等のうちから選ばれる１種または２種
以上が含まれる。さらにまた、不純物として０．Ｎ等を
若干含んでいても磁気特性に及ぼす影響は少ない。
さらに、金属板材としてはステンレス鋼やＮｉ基合金な
どからなるものが用いられるが、特に限定はされない、
そして、この金属板材は、押出成形後において、例えば
モータ用シャフトのボス部分などとして使用される場合
のごとくある程度の機械的強度も要求されるときには、
それなりの板厚のものが使用されるが、単にリング状部
分の内周側におけるクラックの発生をおさえようとする
場合には、機械的強度が小さいかほとんどないような極
くうすいものを使用することもできる。
第１図（ａ）〜（ｄ）は本発明に係るラジアル異方性永
久磁石の製造方法の一実施態様を示すもので、第１図（
ｂ）に示すように、側部型１と、前記側部型１の開口径
よりも小さい面積の抑圧面２ａを有する上部型２と、前
記側部型１の開口径とほぼ等しい面積の押圧面３ａを有
する下部型３とを備えた熱間兼押出成形型４を用いてい
る。
そしてまず、第１図（ａ）に示すように、前記熱間兼押
出成形型４の側部型１と下部型３とによって形成された
成形空間５内に、Ｒ−Ｔ−Ｍを主成分とする希土類−鉄
系磁石粉末６を入れ、次いで前記磁石粉末６の少なくと
も加圧側（またはこの加圧側とともに、非加圧側である
下部型３の抑圧面３ａとの間）に金属板材７を配設して
、第１図（ｂ）に示すように金属板材７側から上部型２
を降下させて前記磁石粉末６を熱間で加圧する熱間成形
を行い、ここで得られた熱間成形体８はそのままにして
、引続きＮＳ１図（Ｃ）に示すように、上部型２による
押圧力をさらに増大させることによって金属板材７およ
び熱間成形体８を塑性変形させる後方押出成形を行い、
熱間兼押出成形型４から取り出すことによって、第１図
（ｄ）に示すように、塑性加工された金属板材７を一体
で備えていると共にリング状部分９ａおよび閉塞端部分
９ｂを有するラジアル異方性永久磁石９を得る。
第２図（ａ）〜（ｄ）は本発明に係るラジアル異方性永
久磁石の製造方法の他の実施態様を示すもので、第１図
に示したと同じ熱間兼押出成形型４を用いている。
そしてまず、第２図（ａ）に示すように、熱間兼押出成
形型４の（Ｉ１１部型１と下部型３とによって形成され
た成形空間５内に、Ｒ−Ｔ−Ｍを主成分とする希土類−
鉄系磁石粉末を冷間成形することにより得た冷間成形体
１６を入れ、次いで前記冷間成形体１６の少なくとも加
圧側（またはこの加圧側とともに、非加圧側である下部
型３の押圧面３ａとの間）に金属板材７を配設して、第
２図（ｂ）に示すように金属板材７側から上部型２を降
下させて前記冷間成形体１６を熱間で加圧する熱間成形
を行い、ここで得られた熱間成形体８はそのままにして
、引続き第２図（Ｃ）に示すように、上部型２による押
圧力をさらに増大させることによって金属板材７および
熱間成形体８を塑性変形させる後方押出成形を行い、熱
間兼押出成形型４から取り出すことによって、第２図（
ｄ）に示すように、塑性加工された金属板材７を一体で
備えていると共にリング状部分９ａおよび閉塞端部分９
ｂを有するラジアル異方性永久磁石９を得る。
このようにして得たラジアル異方性永久磁石９は、その
閉塞端部分９ｂ５よびこの閉塞端部分９ｂにおける金属
板材７までを切除すると共に上端の傾斜部分を切除する
ことによって、リング状のラジアル異方性永久磁石とな
り、また、閉塞端部分９ｂを除去しかつ閉塞端部分９ｂ
における金属板材７は残しておくことによって、モータ
用シャフトに対するボス部分を有するリング状のラジア
ル異方性永久磁石となる。
（発明の作用）
本発明に係るラジアル異方性永久磁石の製造方法では、
Ｒ−Ｔ−Ｍを主成分とする希土類−鉄系磁石粉末を、ま
たはＲ−Ｔ−Ｍを主成分とする希土類−鉄系磁石粉末を
冷間成形することにより得た冷間成形体を、熱間兼押出
成形型内に入れると共に、前記磁石粉末または冷間成形
体の少なくとも加圧面側に金属板材を配設して、前記金
属板材側から前記磁石粉末または前記成形体を熱間で加
圧する熱間成形を行い、次いで前記金属板材側からさら
に押圧する前方または後方押出成形を行って、リング状
部分を有するラジアル異方性永久磁石またはその粗材を
得るようにした構成としているので、前記金属板材の介
在によってリング状部分の内周面側に割れが発生しない
ものとなり、かつまた同一の成形型で熱間成形とその後
の前方または後方押出成形とを行うことによって複合押
出の効果が得られると共に押出成形体に対して対称な歪
が与えられるようになるという作用がもたらされる。
（実施例）
３１重量％Ｎｄ−１，０重量％Ｂ−２．５重量％Ｃ〇−
残部Ｆｅよりなる組成を有し、超急冷法によって製造し
た希土類−鉄系磁石粉末を冷間成形することによって冷
間成形体１６を得た。
次いで、前記冷間成形体１６の上面に、厚さ５ｍｍのス
テンレス鋼（ＳＵＳ３０４）製の金属板材７を載せた状
態にして、８００°Ｃに加熱した熱間兼押出成形型４の
成形空間５内に入れ、圧力１ｔｏｎｆ／ｃｍ２で１分間
加圧する条件で金属板材７側から加圧する熱間成形を行
った。
次いで、同じ成形型４において加圧力を２倍に増やすこ
とによって金属板材７側からざらに押圧する後方押出成
形を行い、次いで熱間兼押出成形型４より取り出して室
温まで冷却し、塑性変形された金属板材７を一体でそな
えている共にリング状部分りａおよび閉塞端部分２ｂを
有する外径３０ｍｍ、内径２５ｍｍ、高さ２０ｍｍのラ
ジアル異方性永久磁石２を得た。
次いで、得られた永久磁石２の外観を調べたところ、・
内周面および外周面のいずれにも割れは全く発生してい
なかった。また、ラジアル方向の磁気特性を調べたとこ
ろ、第１表の実施例の欄に示すとおりであり、周方向に
おける磁気特性のばらつきはほとんどないものであった
。
（比較例）
３１重量％Ｎｄ−１，０重量％Ｂ−２．５重量％Ｃ〇−
残部Ｆｅよりなる組成を有し、超急冷法によって製造し
た希土類−鉄系磁石粉末そ冷間成形することによって冷
間成形体１６を得た。
次いで、前記冷間成形体１６の上面に金属板材（７）を
載せることなく、前記冷間成形体１６のみを８００°Ｃ
に加熱した熱間兼押出成形型４の成形空間５内に入れ、
圧力１ ｔ ｏ ｎ ｆ ／ｃｍ２テ１分間加圧する条
件で熱間成形を行った。
次いで、同じ成形型４において加圧力を２倍に増やすこ
とによってさらに押圧する後方押出成形を行い、熱間兼
押出成形型４より取り出して室温まで冷却し、リング状
部分（９ａ）および閉塞端部分（９ｂ）を有する外径３
０ｍｍ、内径２２ｍｍ、高さ２０ｍｍのラジアル異方性
永久磁石（９）を得た。
次いで、得られた永久磁石９の内周面に１〜３ｍｍ程度
の割れが発生していたため、内周面側を研磨加工するこ
とによって外径３０ｍｍ、内径２５ｍｍ、高さ２０ｍｍ
のラジアル異方性永久磁石とした。そして、ラジアル方
向の磁気特性を調べたところ、第１表の比較例の欄に示
すとおりであり、周方向における磁気特性のばらつきは
ほとんどないものであった。
第 １ 表
第１表に示すように、実施例の永久磁石９の磁気特性は
かなり優れたものであった。一方、比較例の永久磁石（
９）の磁気特性が劣っているのは、圧縮歪の大きな磁気
特性にすぐれた内周部分を研磨加工により除去したこと
、および割れの発生によって歪が解放されたこと、によ
るものと思われる。(Industrial Application Field) The present invention relates to a method for manufacturing a radially anisotropic permanent magnet used for manufacturing a permanent magnet having anisotropy in the radial direction. (Prior Art) In recent years, rare earth-iron magnets have been attracting attention as permanent magnets because of their superior magnetic properties compared to conventional alnico magnets and rare earth-cobalt magnets. This rare earth-iron magnet is made of RT-
It is M-based, and R is a rare earth element. T is an iron-based transition element, and 9M is composed of other elements. In producing a permanent magnet having radial anisotropy in this type of rare earth-iron magnet, the steps shown in FIGS. 3(a) to 3(d), for example, have been used. That is, as shown in FIG. 3(b), a hot forming mold 24 consisting of a side mold 21, an upper mold 22, and a lower mold 23 is used, and as shown in FIG. 3(a), the side mold 21 and lower mold 23
A rare earth-iron magnet powder 26 or a molded body (not shown) obtained by cold-forming rare earth-iron magnet powder is put into the molding space 25 formed by the above, and then, as shown in FIG. 3(b), Then, the upper die 22 is lowered and the rare earth-iron magnet powder 26 and its cold compact are hot-pressed (hot press), and then, as shown in FIG. 3 CC), For this, an extrusion die 34 consisting of a side mold 31, an upper mold 32, and a lower mold 33 is used.
The hot formed body 27 formed by the hot forming mold 24 of FIG. 3(b) is placed into the forming space 35 formed by the upper mold 3.
2 was lowered and backward extrusion was performed to obtain a rear extrusion molded body 35 having a shape as shown in FIG. 83(d), thereby manufacturing a radial anisotropic permanent magnet. (Problems to be Solved by the Invention) However, in such a conventional method for manufacturing a radially anisotropic permanent magnet, cracks 36 tend to occur on the inner peripheral side of the rear extrusion molded body 35, and although the magnetic properties are good, Since the peripheral side had to be polished, there was a problem in that the overall magnetic properties deteriorated. Furthermore, since the hot forming die 24 and the extrusion die 34 are used, and hot forming and backward extrusion cannot be performed using the same forming die, it is not possible to apply symmetrical strain to the extruded body 35. However, there was a problem in that the magnetic properties could vary in the circumferential direction. (Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and even when a permanent magnet rough material is made of an extruded body having a ring-shaped part, the inner peripheral surface side of the ring-shaped part No cracks occur, and therefore there is no need to polish and remove the inner peripheral surface, which has excellent magnetic properties, as would be the case if cracks did occur, so it is possible to have excellent magnetic properties. By performing interforming and extrusion molding using the same mold, symmetrical strain can be applied to the extruded product, and a radially anisotropic permanent magnet with less variation in magnetic properties in the circumferential direction can be provided. The purpose of the present invention is to provide a method for manufacturing a radially anisotropic permanent magnet. [Structure of the Invention] (Means for Solving the Problems) A method for manufacturing a radially anisotropic permanent magnet according to the first claim of the present invention is characterized in that R-T-M (Tazo, R is one of the rare earth elements) T is one or two or more selected from iron group transition elements; M is one or more selected from property improving elements). A rare earth-iron magnet powder is placed in a hot extrusion mold, a metal plate is provided at least on the pressure side of the magnet powder, and the magnet powder is hot-pressed from the metal plate side. A radially anisotropic permanent magnet according to a second aspect of the present invention is constructed such that a radially anisotropic permanent magnet having a ring-shaped portion is obtained by performing interforming and then further pressing from the metal plate side to obtain a radially anisotropic permanent magnet. The method for manufacturing a magnet includes placing a cold compact obtained by cold compacting rare earth-iron magnet powder containing R-T-M as a main component into a hot/extrusion mold, and A metal plate material is arranged at least on the pressurizing surface side of the interformed body, hot forming is performed by hot pressing the formed body from the metal plate side, and then extrusion molding is performed by further pressing from the metal plate side. The present invention is characterized in that it has a configuration in which a radially anisotropic permanent magnet having a ring-shaped portion is obtained, and these configurations are used as a means for solving the above-mentioned conventional problems. The permanent magnet used in the method for producing a radially anisotropic permanent magnet of the present invention is a rare earth-iron type magnet whose main component is R-T-M, where R is Nd, which provides high magnetic properties.
, Pr, relatively low-density Ce, Mitsushmetal, and rare earth elements such as DY and Tb that provide high coercive force. Further, T is one or more selected from iron group transition elements such as Fe, Co, and Ni, and non-iron group transition elements such as Mn. Furthermore, M is B, C
, P, Si, etc., and this M includes one or more elements selected from the group consisting of , P, Si, etc., and in order to improve temperature characteristics, coercive force, squareness of demagnetization curve, corrosion resistance, 9 machinability, etc. , Tf. Zr, Hf, V, Nb, Ta, Cr, Mo, W. Ru, Rh, Pd, Os, Ir, Pt, Cu. Zn, All, Ga, In, Tu, Pb, Bi. One or more types selected from Li, Mg, Ca, etc. are included. Furthermore, as an impurity, 0. Even if a small amount of N or the like is contained, the influence on the magnetic properties is small. Furthermore, the metal plate material used is stainless steel, Ni-based alloy, etc., but is not particularly limited.
When this metal plate material is required to have a certain degree of mechanical strength after extrusion molding, for example when used as a boss part of a motor shaft,
A plate with a certain thickness is used, but if you are simply trying to prevent cracks from forming on the inner circumference of the ring-shaped part, use an extremely thin plate with little or no mechanical strength. You can also do that. FIGS. 1(a) to (d) show an embodiment of the method for manufacturing a radially anisotropic permanent magnet according to the present invention, and FIG.
As shown in b), a side mold 1, an upper mold 2 having a pressing surface 2a having an area smaller than the opening diameter of the side mold 1, and a pressing surface having an area approximately equal to the opening diameter of the side mold 1. A hot extrusion mold 4 is used, which is equipped with a lower mold 3 having a surface 3a. First, as shown in FIG. 1(a), R-T-M is added as a main component into the molding space 5 formed by the side mold 1 and the lower mold 3 of the hot extrusion mold 4. Then, a metal plate 7 is placed at least on the pressurized side of the magnet powder 6 (or between this pressurized side and the suppressing surface 3a of the lower mold 3, which is the non-pressurized side). the upper mold 2 from the metal plate 7 side as shown in FIG. 1(b).
The magnetic powder 6 is hot-pressed by lowering the magnetic powder 6, and the hot-formed body 8 obtained here is left as it is, and then, as shown in FIG. Performing backward extrusion molding in which the metal plate material 7 and the hot formed body 8 are plastically deformed by further increasing the pressing force,
By taking it out from the hot extrusion mold 4, as shown in FIG. A directional permanent magnet 9 is obtained. 2(a) to 2(d) show another embodiment of the method for manufacturing a radially anisotropic permanent magnet according to the present invention, in which the same hot extrusion mold 4 as shown in FIG. 1 is used. ing. First, as shown in FIG. 2(a), R-T-M is added as the main component into the molding space 5 formed by the (I11 part mold 1 and the lower mold 3) of the hot extrusion mold 4. Rare earths
A cold-formed body 16 obtained by cold-forming iron-based magnet powder is placed, and then at least the pressure side of the cold-formed body 16 (or together with this pressure side, the pressing surface of the lower mold 3 which is the non-pressure side) is placed. 3a), and as shown in FIG. 2(b), the upper die 2 is lowered from the side of the metal plate 7 and the cold formed body 16 is hot-pressed. The hot formed body 8 obtained here is left as it is, and the pressing force of the upper die 2 is further increased to form the metal plate 7 and the hot formed body 8 as shown in FIG. 2(C). By performing backward extrusion molding to plastically deform the molded body 8 and taking it out from the hot extrusion mold 4, the shape shown in FIG.
As shown in d), it is integrally equipped with a plastically worked metal plate 7, and also includes a ring-shaped portion 9a and a closed end portion 9.
A radially anisotropic permanent magnet 9 having b is obtained. The thus obtained radially anisotropic permanent magnet 9 is formed into a ring-shaped radially anisotropic permanent magnet by cutting off the closed end portion 9b5 and the metal plate 7 in the closed end portion 9b, as well as cutting off the inclined portion at the upper end. It becomes a directional permanent magnet, and the closed end portion 9b is removed and the closed end portion 9b
By leaving the metal plate material 7 in, it becomes a ring-shaped radially anisotropic permanent magnet having a boss portion for the motor shaft. (Action of the invention) In the method for manufacturing a radially anisotropic permanent magnet according to the present invention,
A cold compact obtained by cold forming a rare earth-iron magnet powder containing R-T-M as the main component, or a rare earth-iron magnet powder containing R-T-M as the main component, While placing the magnetic powder or the cold molded body in a hot extrusion mold, a metal plate is disposed at least on the pressing surface side of the magnetic powder or the cold molded body, and the magnetic powder or the molded body is heated from the metal plate side. The structure is such that a radial anisotropic permanent magnet having a ring-shaped portion or a raw material thereof is obtained by performing hot forming by pressing, and then performing forward or backward extrusion molding by further pressing from the metal plate side. The interposition of the metal plate material prevents cracks from occurring on the inner circumferential surface of the ring-shaped portion, and the effect of composite extrusion is achieved by performing hot forming and subsequent forward or backward extrusion using the same mold. At the same time, symmetrical strain can be applied to the extruded body. (Example) 31% by weight Nd-1.0% by weight B-2.5% by weight C〇-
A cold-formed body 16 was obtained by cold-forming rare earth-iron magnet powder having a composition in which the remainder was Fe and produced by an ultra-quenching method. Next, a metal plate 7 made of stainless steel (SUS304) having a thickness of 5 mm was placed on the upper surface of the cold formed body 16, and the molding space 5 of the hot extrusion mold 4 was heated to 800°C. Hot forming was performed by applying pressure from the metal plate 7 side under conditions of applying pressure of 1 tonf/cm 2 for 1 minute. Next, backward extrusion molding is performed by doubling the pressing force in the same mold 4 to roughly press it from the metal plate 7 side, and then it is taken out from the hot extrusion mold 4 and cooled to room temperature, where it is plastically deformed. A radially anisotropic permanent magnet 2 having an outer diameter of 30 mm, an inner diameter of 25 mm, and a height of 20 mm was obtained, integrally provided with a metal plate material 7 having a ring-shaped portion a and a closed end portion 2b. Next, when the appearance of the obtained permanent magnet 2 was examined, it was found that...
No cracks were found on either the inner or outer circumferential surface. Further, when the magnetic properties in the radial direction were examined, the results were as shown in the Example column of Table 1, and there was almost no variation in the magnetic properties in the circumferential direction. (Comparative example) 31% by weight Nd-1.0% by weight B-2.5% by weight C〇-
A cold-formed body 16 was obtained by cold-forming a rare earth-iron magnet powder having a composition in which the remainder was Fe and produced by an ultra-quenching method. Next, the cold formed body 16 alone is heated to 800°C without placing the metal plate (7) on the upper surface of the cold formed body 16.
into the molding space 5 of the hot extrusion mold 4 heated to
Hot forming was carried out under conditions of pressurization at a pressure of 1 tonf/cm2 for 1 minute. Next, backward extrusion molding is performed in the same mold 4 by doubling the pressing force to further press the mold, and the ring-shaped portion (9a) and the closed end portion are removed from the hot extrusion mold 4 and cooled to room temperature. (9b) outer diameter 3
A radially anisotropic permanent magnet (9) with a diameter of 0 mm, an inner diameter of 22 mm, and a height of 20 mm was obtained. Next, since cracks of about 1 to 3 mm had occurred on the inner peripheral surface of the obtained permanent magnet 9, the inner peripheral surface was polished to have an outer diameter of 30 mm, an inner diameter of 25 mm, and a height of 20 mm.
radially anisotropic permanent magnet. When the magnetic properties in the radial direction were examined, the results were as shown in the Comparative Example column of Table 1, and there was almost no variation in the magnetic properties in the circumferential direction. Table 1 As shown in Table 1, the magnetic properties of the permanent magnet 9 of the example were quite excellent. On the other hand, the permanent magnet of the comparative example (
The reason why the magnetic properties of sample 9) are inferior is probably due to the fact that the inner circumferential portion, which had excellent magnetic properties and had a large compressive strain, was removed by polishing, and that the strain was released by the occurrence of cracks.
本発明に係るラジアル異方性永久磁石の製造方法では、
Ｒ−Ｔ−Ｍを主成分とする希土類−鉄系磁石粉末を、ま
たはＲ−Ｔ−Ｍを主成分とする希土類−鉄系磁石粉末を
冷間成形することにより得た冷間成形体を、熱間兼押出
成形型内に入れると共に、前記磁石粉末または冷間成形
体の少なくとも加圧面側に金属板材を配設して、前記金
属板材側から前記磁石粉末または前記成形体を熱間で加
圧する熱間成形を行い、次いで前記金属板材側からさら
に押圧する前方または後方押出成形を行って、リング状
部分を有するラジアル異方性永久磁石を得るようにした
構成としているので、前記金属板材の介在によってリン
グ状部分の内周面側に割れが発生しないものとなり、し
たがって割れが発生した場合のように加工歪が大きく磁
気特性のすぐれた内周面を研磨して除去することがない
ため磁気特性のすぐれたものとすることが可能であり、
かつまた同一の成形型で熱間成形と押出成形とを行うよ
うにしているので押出成形体に対して対称な歪を与える
ことができ、周方向における磁気特性のばらつきが著し
く少ないラジアル異方性永久磁石を提供することが可能
であるという非常に優れた効果がもたらされる。In the method for manufacturing a radially anisotropic permanent magnet according to the present invention,
A cold compact obtained by cold forming a rare earth-iron magnet powder containing R-T-M as the main component, or a rare earth-iron magnet powder containing R-T-M as the main component, While placing the magnetic powder or the cold molded body in a hot extrusion mold, a metal plate is disposed at least on the pressing surface side of the magnetic powder or the cold molded body, and the magnetic powder or the molded body is heated from the metal plate side. The configuration is such that a radially anisotropic permanent magnet having a ring-shaped portion is obtained by performing hot forming by pressing, and then performing forward or backward extrusion molding by further pressing from the metal plate side. Due to the interposition, cracks do not occur on the inner circumferential surface of the ring-shaped part, and therefore the inner circumferential surface, which has high machining distortion and excellent magnetic properties, does not need to be polished and removed, which would be the case if a crack were to occur. It is possible to have excellent characteristics,
Furthermore, since hot forming and extrusion are performed using the same mold, symmetrical strain can be applied to the extruded product, resulting in radial anisotropy with significantly less variation in magnetic properties in the circumferential direction. The very advantageous effect is that it is possible to provide permanent magnets.
第１図（ａ）〜（ｄ）は本発明に係るラジアル異方性永
久磁石の製造方法の一実施態様を工程順に示す断面説明
図、第２図（ａ）〜（ｄ）は本発明に係るラジアル異方
性永久磁石の製造方法の他の実施態様を工程順に示す断
面説明図、第３図（ａ）〜（ｄ）は従来のラジアル異方
性永久磁石の製造方法を工程順に示す断面説明図である
。
４・・・熱間兼押出成形型、
５・・・成形空間、
６・・・希土類−鉄系磁石粉末。
７・・・金属板材、
８・・・熱間成形体、
９・・・押出成形体（ラジアル異方性永久磁石）、９ａ
・・・リング状部分、
１６・・・希土類−鉄系合金粉末の冷間成形体。
特許出願人 大同特殊鋼株式会社代理人弁理士
小 塩 豊
第３図（０）
第３図（Ｃ）
第３図（ｂ）
第３図（ｄ）FIGS. 1(a) to (d) are cross-sectional explanatory diagrams showing one embodiment of the method for manufacturing a radial anisotropic permanent magnet according to the present invention in the order of steps, and FIGS. 2(a) to (d) are A cross-sectional explanatory diagram showing another embodiment of the method for producing a radially anisotropic permanent magnet according to the order of steps, and FIGS. It is an explanatory diagram. 4... Hot extrusion mold, 5... Molding space, 6... Rare earth-iron magnet powder. 7... Metal plate material, 8... Hot formed body, 9... Extruded body (radial anisotropic permanent magnet), 9a
...Ring-shaped portion, 16...Cold compact of rare earth-iron alloy powder. Patent applicant: Daido Steel Co., Ltd. Representative Patent Attorney
Yutaka Oshio Figure 3 (0) Figure 3 (C) Figure 3 (b) Figure 3 (d)
Claims (2)
を熱間兼押出成形型内に入れると共に、前記磁石粉末の
少なくとも加圧面側に金属板材を配設して、前記金属板
材側から前記磁石粉末を熱間で加圧する熱間成形を行い
、次いで前記金属板材側からさらに押圧する押出成形を
行って、リング状部分を有するラジアル異方性永久磁石
を得ることを特徴とするラジアル異方性永久磁石の製造
方法。(1) Rare earth-iron magnet powder containing R-T-M as a main component is placed in a hot extrusion mold, and a metal plate is disposed at least on the pressure side of the magnet powder, and the metal A radially anisotropic permanent magnet having a ring-shaped portion is obtained by hot forming in which the magnet powder is hot pressed from the plate side, and then extrusion molding in which it is further pressed from the metal plate side. A method for manufacturing a radially anisotropic permanent magnet.
を冷間成形することにより得た冷間成形体を熱間兼押出
成形型内に入れると共に、前記冷間成形体の少なくとも
加圧面側に金属板材を配設して、前記金属板材側から前
記成形体を熱間で加圧する熱間成形を行い、次いで前記
金属板材側からさらに押圧する押出成形を行って、リン
グ状部分を有するラジアル異方性永久磁石を得ることを
特徴とするラジアル異方性永久磁石の製造方法。(2) A cold-formed body obtained by cold-forming a rare earth-iron magnet powder containing R-T-M as a main component is placed in a hot extrusion mold, and the cold-formed body is A metal plate is disposed at least on the pressurizing surface side, hot forming is performed by hot pressing the molded body from the metal plate side, and then extrusion molding is performed by further pressing from the metal plate side to form a ring shape. 1. A method for producing a radially anisotropic permanent magnet, the method comprising obtaining a radially anisotropic permanent magnet having a radially anisotropic permanent magnet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8498589A JP2757442B2 (en) | 1989-04-04 | 1989-04-04 | Manufacturing method of radial anisotropic permanent magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8498589A JP2757442B2 (en) | 1989-04-04 | 1989-04-04 | Manufacturing method of radial anisotropic permanent magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02263415A true JPH02263415A (en) | 1990-10-26 |
| JP2757442B2 JP2757442B2 (en) | 1998-05-25 |
Family
ID=13845916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8498589A Expired - Lifetime JP2757442B2 (en) | 1989-04-04 | 1989-04-04 | Manufacturing method of radial anisotropic permanent magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2757442B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005086103A (en) * | 2003-09-10 | 2005-03-31 | Ricoh Co Ltd | Method and device of manufacturing rare earth magnet block |
| CN106890863A (en) * | 2017-03-28 | 2017-06-27 | 解伟 | A kind of heat back of the body radially oriented ring press of extrusion |
-
1989
- 1989-04-04 JP JP8498589A patent/JP2757442B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005086103A (en) * | 2003-09-10 | 2005-03-31 | Ricoh Co Ltd | Method and device of manufacturing rare earth magnet block |
| CN106890863A (en) * | 2017-03-28 | 2017-06-27 | 解伟 | A kind of heat back of the body radially oriented ring press of extrusion |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2757442B2 (en) | 1998-05-25 |
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