JPH07138672A - Production of rare earth permanent magnet - Google Patents
Production of rare earth permanent magnetInfo
- Publication number
- JPH07138672A JPH07138672A JP3334440A JP33444091A JPH07138672A JP H07138672 A JPH07138672 A JP H07138672A JP 3334440 A JP3334440 A JP 3334440A JP 33444091 A JP33444091 A JP 33444091A JP H07138672 A JPH07138672 A JP H07138672A
- Authority
- JP
- Japan
- Prior art keywords
- sintering
- temperature
- rare earth
- permanent magnet
- liquid phase
- 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.)
- Pending
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/0555—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together
- H01F1/0557—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together sintered
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- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Powder Metallurgy (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【００１０】[0010]
【産業上の利用分野】本発明は、希土類元素または希土
類元素と遷移元素とを主成分とするＲ2 Ｍ17系（但し、
ＲはＳｍ，Ｎｄ，Ｐｒ，Ｙ，Ｃｅを含む希土類元素、Ｍ
は主として遷移元素を表す）永久磁石合金に関し、特に
保磁力（ｂＨｃ）および角形比（（ＢＨ）ｍａｘ／Ｂｒ
2 ）を改善する製造方法に関するものである。また、永
久磁石合金の製造原価を改善する製造方法に関するもの
である。BACKGROUND OF THE INVENTION The present invention relates to a R 2 M 17 system containing a rare earth element or a rare earth element and a transition element as main components (however,
R is a rare earth element containing Sm, Nd, Pr, Y and Ce, M
Mainly represents a transition element), particularly, a coercive force (bHc) and a squareness ratio ((BH) max / Br)
2 ) It relates to a manufacturing method for improving. It also relates to a manufacturing method for improving the manufacturing cost of the permanent magnet alloy.
【００２０】[0020]
【従来の技術】近年、保磁力、残留磁束密度、角形比等
の磁気特性の優れた希土類永久磁石としてＳｍ−Ｃｏ系
の2-17型が開発されて広く使用されている。また、この
永久磁石は高価なＳｍを多量に含有しているため、Ｓｍ
の一部をＮｄ、Ｐｒ等の安価な希土類元素に置換した永
久磁石（2-17低コスト型）の開発も多く行われている。
他方、この2-17低コスト型は、Ｓｍの一部がＮｄ、Ｐｒ
等に置換されているために磁気特性が低下する。そこ
で、その改善のためにＭｎ、Ｚｒ等の遷移元素やＢ、Ｐ
等の微量元素を添加したりしている。2. Description of the Related Art In recent years, Sm-Co type 2-17 type has been developed and widely used as a rare earth permanent magnet having excellent magnetic properties such as coercive force, residual magnetic flux density and squareness ratio. Further, since this permanent magnet contains a large amount of expensive Sm, Sm
Many permanent magnets (2-17 low-cost type) have been developed in which a part of Nd, Pr is replaced with an inexpensive rare earth element.
On the other hand, in this 2-17 low cost type, part of Sm is Nd, Pr.
And the like, the magnetic characteristics are deteriorated. Therefore, in order to improve it, transition elements such as Mn and Zr and B and P
Trace elements such as are added.
【００３０】このような希土類永久磁石の組成による磁
気特性の改善の開発に加えて、製造方法による磁気特性
改善の改善も多く提案されている。例えば、時効処理の
改善については次のような開示がある。 イ）特公平２−４８６１６号では、特定の合金組成にお
いて複数回の時効処理方法により角形比と保磁力ｉＨｃ
の改善が開示されている。 ロ）特開昭６１−１３６６３１号および特開昭６１−２
１０１６１号では、特定の合金組成において繰返し時効
処理（３回）方法により最大エネルギー積（ＢＨ）ｍａ
ｘの改善が開示されている。次に、溶体化処理と時効処
理の組合わせによる改善には次の開示がある。 ハ）特公平２−２７４２５号では、特定の合金組成にお
いて焼結温度より１０〜５０℃低い温度で溶体化処理
し、次いで繰返し時効処理（２回）する方法により保磁
力ｉＨｃの改善が報告されている。In addition to the development of the improvement of the magnetic characteristics by the composition of such rare earth permanent magnet, many improvements of the magnetic characteristics by the manufacturing method have been proposed. For example, there is the following disclosure regarding improvement of aging treatment. B) In Japanese Examined Patent Publication No. 2-48616, the squareness ratio and the coercive force iHc are obtained by aging treatment methods for a specific alloy composition a plurality of times.
Improvements have been disclosed. B) JP-A-61-136631 and JP-A-61-2
In No. 10161, the maximum energy product (BH) ma was determined by the repeated aging treatment (3 times) in a specific alloy composition.
An improvement in x is disclosed. Next, there is the following disclosure regarding improvement by a combination of solution treatment and aging treatment. C) In Japanese Patent Publication No. 27425/1990, improvement of coercive force iHc is reported by a method of solution treatment at a temperature lower than the sintering temperature by 10 to 50 ° C. and then repeated aging treatment (twice) in a specific alloy composition. ing.
【００４０】また、焼結と時効処理の組合わせによる改
善には次の開示がある。 ニ）特公昭６０−３４６３２号では、特定の合金組成に
おいて１１００〜１２５０℃の温度で一次焼結し、つい
で１１５０〜１２５０℃の温度で、かつこの一次焼結温
度よりも３〜３０℃高い温度で二次焼結を行ったのち、
２段時効処理する方法により角形比、保磁力ｉＨｃの改
善が報告されている。さらに、焼結、溶体化処理および
時効処理の組合わせによる改善には次の開示がある。 ホ）特公平３−２８５０２号では、特定の合金組成にお
いて特定の焼結・溶体化処理並びに２段時効処理する方
法により保磁力ｉＨｃ、角形比の改善が報告されてい
る。Further, there is the following disclosure for improvement by a combination of sintering and aging treatment. D) According to Japanese Examined Patent Publication No. 60-34632, primary sintering is performed at a temperature of 1100 to 1250 ° C. in a specific alloy composition, then at a temperature of 1150 to 1250 ° C., and a temperature 3 to 30 ° C. higher than the primary sintering temperature. After performing secondary sintering in
Improvements in squareness ratio and coercive force iHc have been reported by the two-step aging treatment method. Further, there is the following disclosure regarding improvement by a combination of sintering, solution treatment and aging treatment. (E) In Japanese Patent Publication No. 28502/1989, improvement of coercive force iHc and squareness ratio is reported by a specific sintering / solution treatment and a two-step aging treatment in a specific alloy composition.
【００５０】以上の希土類永久磁石の組成による磁気特
性改善あるいは製造方法による磁気特性改善の報告によ
ると、保磁力の改善はｉＨｃについてなされている。本
発明者らが改善しようとしている保磁力ｂＨｃと前記ｉ
Ｈｃの関係を、株式会社総合技術センター発行の「永久
磁石の開発・材料設計と磁気回路の解析・設計応用技
術」（昭和６１年）から引用して図１に示す。ｂＨｃは
残留磁化によって支配され、その上限値は４πＩr であ
る。なお、ｂＨｃとｉＨｃの値の大小関係はｂＨｃ＜ｉ
Ｈｃである。According to the above reports on the improvement of the magnetic properties by the composition of the rare earth permanent magnet or the improvement of the magnetic properties by the manufacturing method, the coercive force is improved for iHc. The coercive force bHc and the i
The relationship of Hc is shown in Fig. 1 by quoting "Development of permanent magnets, material design and analysis of magnetic circuits, design application technology" (1986) issued by Sogo Gijutsu Center. bHc is dominated by remanent magnetization, and its upper limit value is 4πI r . Note that the magnitude relationship between the values of bHc and iHc is bHc <i
Hc.
【００６０】[0060]
【図１】[Figure 1]
【００７０】[0070]
【発明が解決しようとする課題】これらの製造方法の開
示は、第１に特定の合金組成における磁気特性改善のた
めの製造方法であり、第２に特定の時効処理を必須とし
ており、時効処理のみ又は時効処理と他の処理との組合
わせからなり、第３に改善された磁気特性は角形比、保
磁力ｉＨｃ又は最大エネルギー積（ＢＨ）ｍａｘに関す
るものである。また、以上のような磁気特性改善のため
の開示はされているが、高価な希土類永久磁石の製造原
価を低減するための製造方法の改善は報告されていな
い。本発明の目的は、2-17型希土類永久磁石の磁気特
性、特に保磁力（ｂＨｃ）および角形比の改善を焼結方
法のみで行うことを提供するものである。さらに、2-17
型希土類永久磁石の焼結時における製造歩留りの向上の
ための焼結方法を提供するものである。DISCLOSURE OF THE INVENTION Disclosure of these manufacturing methods is, firstly, a manufacturing method for improving magnetic properties in a specific alloy composition, and secondly, specific aging treatment is indispensable. A third or improved magnetic property consisting of only or an aging treatment in combination with another treatment relates to the squareness ratio, the coercive force iHc or the maximum energy product (BH) max. Further, although the disclosure for improving the magnetic characteristics as described above has been made, no improvement in the manufacturing method for reducing the manufacturing cost of the expensive rare earth permanent magnet has been reported. An object of the present invention is to improve the magnetic properties of 2-17 type rare earth permanent magnets, especially the coercive force (bHc) and the squareness ratio, only by the sintering method. In addition, 2-17
The present invention provides a sintering method for improving the manufacturing yield at the time of sintering a rare earth permanent magnet of the type.
【００８０】[0080]
【課題を解決するための手段】本発明者等は2-17型希土
類永久磁石に関し、その焼結方法が液相焼結であること
に注目して保磁力（ｂＨｃ）および角形比（（ＢＨ）ｍ
ａｘ／Ｂｒ2 ）の改善ならびに焼結時における製造歩留
りの向上のため鋭意研究した結果、液相晶出開始温度で
一次焼結し、続いて二次焼結を行う２段焼結方法により
前記目的を達成することを見出し、本発明を完成するに
至ったものである。DISCLOSURE OF THE INVENTION The inventors of the present invention relate to a 2-17 type rare earth permanent magnet and note that the sintering method is liquid phase sintering, and the coercive force (bHc) and the squareness ratio ((BH ) M
ax / Br 2 ) and the production yield at the time of sintering. As a result of intensive research, as a result of the two-stage sintering method of performing primary sintering at a liquid phase crystallization start temperature and then performing secondary sintering, The inventors have found that the object is achieved and completed the present invention.
【００９０】以下、本発明について詳細に説明する。本
発明は2-17型希土類永久磁石に関するものであり、その
焼結が液相焼結からなる2-17型希土類永久磁石の焼結方
法に係わるものである。この2-17型希土類永久磁石の合
金組成について、好ましくは次の実用範囲とした。この
2-17型希土類永久磁石における希土類元素Ｒ（Ｓｍ、Ｎ
ｄ，Ｐｒ，Ｙ，Ｃｅの１種以上）の含有量が２２％未満
では、ｉＨｃが低下し、（ＢＨ）ｍａｘも低下する。２
７％を越えるとＢｒが低下するからである。Ｆｅの含有
量が、１０未満ではＢｒが低下し、２５％を越えるとｉ
Ｈｃが低下するからである。遷移元素Ｍ（Ｍｎ，Ｔｉ，
Ｚｒ，Ｈｆの１種以上）の含有量が０．５％未満では十
分なｉＨｃが得られず、６％を越えるとＢｒが低下する
からである。微量元素Ｂの含有量が、０．００３未満で
は角形性改善の効果が少なく、０．０１５％を越えると
ｉＨｃが低下するからである。また、微量元素Ｐ，Ｓが
０．００３未満では角形性改善の効果が少なく、０．０
１０％をこえるとｉＨｃが低下するからである。なお、
本発明においては液相焼結からなる2-17型希土類永久磁
石の保磁力ｂＨｃおよび角形比を改善したい場合、又は
焼結時における製造歩留りを改善したい場合には上記の
合金組成の範囲に限るものではない。The present invention will be described in detail below. The present invention relates to a 2-17 type rare earth permanent magnet, and to a method for sintering a 2-17 type rare earth permanent magnet, the sintering of which is liquid phase sintering. The alloy composition of this 2-17 type rare earth permanent magnet is preferably set to the following practical range. this
2-17 type rare earth permanent magnet R (Sm, N
If the content of d, Pr, Y, or Ce) is less than 22%, iHc decreases and (BH) max also decreases. Two
This is because if it exceeds 7%, Br decreases. If the Fe content is less than 10, Br decreases, and if it exceeds 25%, i decreases.
This is because Hc decreases. Transition element M (Mn, Ti,
This is because if the content of one or more of Zr and Hf) is less than 0.5%, sufficient iHc cannot be obtained, and if it exceeds 6%, Br decreases. This is because if the content of the trace element B is less than 0.003, the effect of improving the squareness is small, and if it exceeds 0.015%, the iHc decreases. If the trace elements P and S are less than 0.003, the effect of improving the squareness is small, and
This is because iHc decreases when it exceeds 10%. In addition,
In the present invention, when it is desired to improve the coercive force bHc and squareness ratio of a 2-17 type rare earth permanent magnet formed by liquid phase sintering, or to improve the manufacturing yield during sintering, the range is limited to the above alloy composition. Not a thing.
【０１００】この2-17型希土類永久磁石の製造方法は、
所定成分からなる合金粉末を磁場プレスで成形した後、
不活性ガス（例えばアルゴンガス）あるいは還元性ガス
（例えば水素ガス）雰囲気中で焼結、溶体化処理、時効
処理の工程からなる。本発明の方法では、この焼結工程
において液相晶出温度である１１２０〜１２００℃で一
次焼結を行い、次いで一次焼結温度よりも２０〜３０℃
高い１１４０〜１２３０℃で二次焼結を実施する。従来
の２段焼結方法では、緻密（＝焼結体の密度上昇）でか
つ均質な永久磁石を得るために高温の焼結温度で一次焼
結を行い、続いて一次焼結温度よりもさらに高い温度１
１５０〜１２６０℃で二次焼結を実施している。すなわ
ち、2-17型希土類永久磁石は液相と固相の２相の相互拡
散により焼結が進んでいる。したがって、焼結温度を高
くすることにより多量の液相が晶出するため焼結体の密
度が上昇し、角形比が改善されることを開示している。This 2-17 type rare earth permanent magnet is manufactured by
After molding the alloy powder consisting of predetermined components with a magnetic field press,
The steps include sintering, solution treatment, and aging treatment in an atmosphere of an inert gas (for example, argon gas) or a reducing gas (for example, hydrogen gas). In the method of the present invention, in this sintering step, primary sintering is performed at a liquid phase crystallization temperature of 1120 to 1200 ° C., and then 20 to 30 ° C. higher than the primary sintering temperature.
Perform secondary sintering at a high 1140-1230 ° C. In the conventional two-stage sintering method, primary sintering is performed at a high sintering temperature in order to obtain a dense (= increased density of the sintered body) and homogeneous permanent magnet, and then a temperature higher than the primary sintering temperature. High temperature 1
Secondary sintering is performed at 150 to 1260 ° C. That is, the 2-17 type rare earth permanent magnet is being sintered due to mutual diffusion of two phases, a liquid phase and a solid phase. Therefore, it is disclosed that by increasing the sintering temperature, a large amount of liquid phase is crystallized, so that the density of the sintered body is increased and the squareness ratio is improved.
【０１１０】本発明では、一次焼結は１１２０〜１２０
０℃の液相晶出開始温度という焼結温度より低温で実施
する。低温のため液相の発生が少ない状態で焼結は進行
する。したがって、一次焼結が終了した時点では、包晶
反応により固相化し組成の均一化をおこしている。ま
た、次の高温焼結に先立って低温焼結を実施しているた
めに、高温焼結時に液相焼結によって生ずる焼結体の変
形が少なくなる。次に、一次焼結温度より２０〜３０℃
高い温度１１４０〜１２３０℃で二次焼結を実施する。
これによって、緻密でかつ組成の均一な微細な結晶組織
を有する焼結体が得られて角形比と保磁力ｂＨｃの改善
が確認された。In the present invention, the primary sintering is 1120-120.
It is performed at a temperature lower than the sintering temperature of 0 ° C., which is a liquid phase crystallization start temperature. Since the temperature is low, the sintering proceeds in a state where the generation of the liquid phase is small. Therefore, when the primary sintering is completed, the solid is solidified by the peritectic reaction to homogenize the composition. Further, since the low temperature sintering is performed prior to the next high temperature sintering, the deformation of the sintered body caused by the liquid phase sintering during the high temperature sintering is reduced. Next, 20-30 ° C from the primary sintering temperature
Secondary sintering is carried out at high temperatures of 1140-1230 ° C.
As a result, a sintered body having a dense and fine composition and a uniform crystal structure was obtained, and it was confirmed that the squareness ratio and the coercive force bHc were improved.
【０１２０】一次焼結温度より高くする温度が２０℃未
満では液相の晶出量が少ないために密度の上昇ができ
ず、従来の１段焼結に比べて角形比と保磁力ｂＨｃは改
善されていない。他方、３０℃を越えると液相の晶出が
増加して緻密化は進む。しかし、結晶粒は粗大化し、主
成分のＳｍ、Ｃｕ等が偏析を生じ始める。この偏析を解
消してｂＨｃと角形比を回復させるために、次の溶体化
処理時間で長時間処理する必要がある。図２には、１
６．２％Ｓｍ−９．３％Ｎｄ−１３．６％Ｆｅ−６．３
％Ｃｕ−２．４％Ｚｒ−０．３％Ｍｎ−０．３％Ｔｉ−
０．００６％Ｂの合金組成について密度、そして保磁力
ｂＨｃと角形比に及ぼす二次焼結温度の影響を示す。横
軸には、液相晶出温度ＴLSと二次焼結の際に一次焼結温
度より高くする温度をとり、縦軸には二次焼結体の密
度、そして二次焼結体の保磁力ｂＨｃと角形比の値を示
す。液相晶出温度ＴLSで焼結した一次焼結体の密度は、
７．８０ｇ／ｃｍ3 であり、二次焼結温度を液相晶出温
度ＴLSより高い温度で二次焼結を行うと＋２０〜＋３０
℃で二次焼結体の密度は８．１７〜８．２０ｇ／ｃｍ3
で飽和している。また、保磁力ｂＨｃと角形比の値も液
相晶出温度ＴLSで焼結した一次焼結体の密度は低いけれ
ども、二次焼結において二次焼結の温度の上昇により、
増加傾向を示すが、＋２０〜＋３０℃をピークに減少傾
向に変わる。図３および図４には図２に示した合金組成
について、本発明による二次焼結体を溶体化処理して調
べたミクロ組織を図３に、従来の一段焼結体を溶体化処
理して調べたミクロ組織を図４に示す。If the temperature higher than the primary sintering temperature is lower than 20 ° C., the crystallized amount of the liquid phase is small and the density cannot be increased, and the squareness ratio and the coercive force bHc are improved as compared with the conventional one-step sintering. It has not been. On the other hand, when the temperature exceeds 30 ° C, crystallization of the liquid phase increases and densification progresses. However, the crystal grains become coarse, and Sm, Cu, etc., which are the main components, begin to segregate. In order to eliminate this segregation and recover bHc and the squareness ratio, it is necessary to carry out the solution treatment for a long time at the next solution treatment time. In FIG. 2, 1
6.2% Sm-9.3% Nd-13.6% Fe-6.3
% Cu-2.4% Zr-0.3% Mn-0.3% Ti-
The influence of the secondary sintering temperature on the density, and the coercive force bHc and squareness is shown for an alloy composition of 0.006% B. The abscissa represents the liquid phase crystallization temperature T LS and the temperature higher than the primary sintering temperature during the secondary sintering, the ordinate represents the density of the secondary sintered body, and the temperature of the secondary sintered body. The values of coercive force bHc and squareness ratio are shown. The density of the primary sintered body sintered at the liquid phase crystallization temperature T LS is
7.80 g / cm 3, which is +20 to +30 when the secondary sintering is performed at a temperature higher than the liquid phase crystallization temperature T LS.
Density of ℃ secondary sintered body 8.17~8.20g / cm 3
Is saturated with. Further, the coercive force bHc and the squareness ratio are also low in the density of the primary sintered body sintered at the liquid phase crystallization temperature T LS , but due to the increase in the temperature of the secondary sintering in the secondary sintering,
It shows an increasing tendency, but changes to a decreasing tendency with a peak at +20 to + 30 ° C. FIGS. 3 and 4 show the microstructure of the alloy composition shown in FIG. 2 which is obtained by subjecting the secondary sintered body according to the present invention to solution treatment, and FIG. The microstructure examined by the above is shown in FIG.
【０１３０】[0130]
【図２】[Fig. 2]
【０１４０】[0140]
【図３】[Figure 3]
【０１５０】[0150]
【図４】[Figure 4]
【０１６０】従来法では、成形体を高温まで昇温して液
相を多量に晶出させるため液相が自重によって焼結進行
中の成形体の下部の方へ移動する。このために焼結体の
下部が膨らんで変形する。また、焼結進行中の成形体の
底面まで達した液相が焼結時に成形体をのせて使う焼結
用トレーと溶着して焼結後の冷却時に割れたり、トレー
から焼結体を離脱するときに割れたりする。しかし、本
発明では低温で一次焼結した焼結体を用いて高温の二次
焼結を実施する。この際に、始めから高温焼結する場合
に比べて、すでに低温の一次焼結を行っているので包晶
反応による固相化と組成の均一化が進んでいる焼結体を
高温焼結の母材としている。このため、高温に昇温して
も液相が母材の下部の方へ移動が妨げられて変形あるい
は割れの発生は防止されると考えられる。In the conventional method, since the compact is heated to a high temperature to crystallize a large amount of the liquid phase, the liquid phase moves to the lower part of the compact during sintering due to its own weight. Therefore, the lower part of the sintered body swells and is deformed. In addition, the liquid phase that has reached the bottom surface of the molded body during sintering is welded to the sintering tray used by placing the molded body during sintering and cracks during cooling after sintering, or the sintered body is detached from the tray. It breaks when you do. However, in the present invention, high temperature secondary sintering is carried out using a sintered body which is primary sintered at low temperature. At this time, compared with the case of performing high temperature sintering from the beginning, since low temperature primary sintering has already been performed, a sintered body that has been solidified by a peritectic reaction and has a uniform composition has been subjected to high temperature sintering. It is used as a base material. Therefore, it is considered that even if the temperature is raised to a high temperature, the movement of the liquid phase toward the lower part of the base material is hindered and the occurrence of deformation or cracking is prevented.
【０１７０】本発明による２段焼結方法を行った焼結体
は、続いて溶体化処理および時効処理が施される。これ
らの処理は公知の方法で行っても、本発明の２段焼結方
法による効果は減じられるものではない。また、本発明
に加えて、溶体化処理又は時効処理において特定の方法
を採用することで本発明の２段焼結方法による効果が減
じられるものではない。The sintered body which has been subjected to the two-stage sintering method according to the present invention is subsequently subjected to solution treatment and aging treatment. Even if these treatments are performed by a known method, the effect of the two-step sintering method of the present invention is not diminished. In addition to the present invention, the effect of the two-step sintering method of the present invention is not reduced by adopting a specific method in the solution treatment or aging treatment.
【０１８０】[0180]
【実施例】表１には、供試合金Ａ１〜Ｃ５の組成を示
す。請求項１に示す合金組成をＡおよびＢシリーズとし
て、請求項２に示す合金組成をＣシリーズとして示す。[Examples] Table 1 shows the compositions of matchmaking funds A1 to C5. The alloy composition shown in claim 1 is shown as A and B series, and the alloy composition shown in claim 2 is shown as C series.
【０１８０】[0180]
【表１】 [Table 1]
【０１９０】表２には、供試合金Ａ１〜Ｃ５の液相晶出
開始温度を示す。液相晶出開始温度はＤＴＡ（示差熱分
析）法により測定した。すなわち、供試合金の粉末を直
径３．０ｍｍ、高さ１．５ｍｍに成形し、ＤＴＡを用い
て、粉末成形体を毎分５℃で加熱し昇温した。液相が晶
出し始めると吸熱ピークが出現する。このピーク出現温
度から高温側５℃程度を有した温度範囲を液相晶出温度
とした。Table 2 shows the liquid crystal crystallization start temperatures of the matchmaking funds A1 to C5. The liquid phase crystallization onset temperature was measured by the DTA (differential thermal analysis) method. That is, powder of match money was molded into a diameter of 3.0 mm and a height of 1.5 mm, and the powder compact was heated at 5 ° C. per minute with DTA to raise the temperature. An endothermic peak appears when the liquid phase begins to crystallize. The temperature range having about 5 ° C. on the high temperature side from this peak appearance temperature was defined as the liquid phase crystallization temperature.
【０２００】[0200]
【表２】 [Table 2]
【０２１０】表３には、本発明法による焼結条件を合金
組成Ａ１〜Ｃ５について示す。一次焼結温度は、表２に
示す液相晶出開始温度であり、二次焼結温度は一次焼結
温度より２０〜３０℃高い温度とした。この二次焼結温
度は、供試合金の粉末を１４φｘ１２ｍｍに成形し、次
いで一次焼結温度て焼結後、二次焼結温度を設定するた
めの実験を行って求めた。また、本発明の２段焼結と比
較するために合金組成Ａ１〜Ｃ５について従来法として
１段焼結を行った。１段焼結の条件としては、本発明の
２段焼結における二次焼結の条件で焼結した。なお、一
次焼結温度における保持時間は４５分、二次焼結温度に
おける保持時間は６０分である。従来法の１段焼結の焼
結時間は、本発明法による二次焼結温度における保持時
間はとおなじ６０分とした。Table 3 shows the sintering conditions according to the method of the present invention for the alloy compositions A1 to C5. The primary sintering temperature was the liquid phase crystallization start temperature shown in Table 2, and the secondary sintering temperature was set to a temperature 20 to 30 ° C. higher than the primary sintering temperature. The secondary sintering temperature was obtained by molding a powder of match alloy into 14φ × 12 mm, then sintering at the primary sintering temperature, and then conducting an experiment for setting the secondary sintering temperature. Further, for comparison with the two-step sintering of the present invention, the alloy compositions A1 to C5 were subjected to one-step sintering as a conventional method. As the conditions for the first-stage sintering, the conditions for the secondary sintering in the two-stage sintering of the present invention were used. The holding time at the primary sintering temperature is 45 minutes, and the holding time at the secondary sintering temperature is 60 minutes. The sintering time for the first-stage sintering according to the conventional method was the same as the holding time at the secondary sintering temperature according to the method of the present invention, which was 60 minutes.
【０２２０】[0220]
【表３】 [Table 3]
【０２３０】次に、こうして得られた焼結体について、
次いで従来公知の方法による溶体化処理および時効処理
を行った。すなわち、溶体化処理は二次焼結温度より２
０〜４０℃低い温度でおこない、時効処理温度は７５０
〜９００℃で等温処理後０．５〜５℃／ｍｉｎで４００
℃まで徐冷し、次いで急冷を行った。表４には、合金組
成Ａ１〜Ｃ５について本発明法と比較として従来法によ
り作成した希土類永久磁石の保磁力ｂＨｃおよび角形比
を測定した結果を示す。Next, regarding the sintered body thus obtained,
Then, solution treatment and aging treatment were performed by a conventionally known method. That is, the solution treatment is performed at a temperature higher than the secondary sintering temperature by 2
The aging treatment temperature is 750.
After isothermal treatment at ~ 900 ° C, 400 at 0.5-5 ° C / min
It was gradually cooled to 0 ° C and then rapidly cooled. Table 4 shows the results of measuring the coercive force bHc and the squareness ratio of the rare earth permanent magnet prepared by the conventional method as a comparison with the method of the present invention for the alloy compositions A1 to C5.
【０２４０】[0240]
【表４】 [Table 4]
【０２５０】表４の結果から、合金組成にかかわらず本
発明による２段焼結法を行うことにより従来の１段焼結
法に比べて、保磁力ｂＨｃは０．３〜１．１ｋＯｅ改善
され、角形比も０．０３〜０．０６改善されていること
が認められる。From the results shown in Table 4, the coercive force bHc is improved by 0.3 to 1.1 kOe as compared with the conventional one-step sintering method by performing the two-step sintering method according to the present invention regardless of the alloy composition. It is recognized that the squareness ratio is also improved by 0.03 to 0.06.
【０２６０】さらに、本発明の２段焼結法の実験から二
次焼結における焼結体の変形が発生せず、焼結用トレー
との溶着も認められないのがわかった。そこで合金組成
Ａ１、Ｂ２、Ｂ４およびＣ５について、合金粉末を２０
φｘ２０ｍｍに各２０個づつ成形した。次いで、本発明
法と従来法による焼結を各１０個づつおこない焼結トレ
ーへの溶着個数と焼結体の変形個数を調べた結果を表５
に示す。焼結トレーへの溶着個数とは、焼結後に焼結体
を焼結トレーから取り出すことができないように溶着し
ている個数をいう。また、焼結体の変形個数とは、焼結
前後における焼結体の直径の偏形率が１０％を越えてい
る個数をいう。なお、本発明法および従来法の焼結条件
は表３と同一条件で行った。表５から、従来法では焼結
トレーへの溶着や焼結体の変形が発生して製品歩留りを
低下させるが、本発明法では焼結トレーへの溶着個数と
焼結体の変形個数は皆無であるため製品歩留りが向上し
製造原価の低減が改善される。Further, from the experiment of the two-step sintering method of the present invention, it was found that the sintered body was not deformed in the secondary sintering, and the welding to the sintering tray was not observed. Therefore, for alloy compositions A1, B2, B4 and C5, 20 alloy powders were used.
20 pieces each were formed in φx20 mm. Next, the results of examining the number of welds on the sintering tray and the number of deformations of the sintered body by performing 10 sinterings each by the method of the present invention and the conventional method are shown in Table 5.
Shown in. The number of pieces welded to the sintering tray means the number of pieces welded so that the sintered body cannot be taken out from the sintering tray after sintering. The number of deformed sintered bodies means the number of deformed diameters of the sintered body before and after sintering exceeding 10%. The sintering conditions of the method of the present invention and the conventional method were the same as those in Table 3. From Table 5, in the conventional method, welding to the sintering tray or deformation of the sintered body occurs and the product yield is lowered, but in the method of the present invention, there is no welding number to the sintering tray and no deformation number of the sintered body. Therefore, the product yield is improved and the manufacturing cost is reduced.
【０２７０】[0270]
【表５】 [Table 5]
【０２８０】[0280]
【発明の効果】本発明の２段焼結法、すなわち液相晶出
温度で一次焼結を行い、次いで一次焼結温度より２０〜
３０℃高い焼結温度で二次焼結する方法によって得られ
た希土類永久磁石の磁気特性は、従来法の１段焼結法に
よるものに比較して保持力ｂＨＣおよび角形比（（Ｂ
Ｈ）ｍａｘ／Ｂｒ2)が優れている。また、焼結時におけ
る変形や焼結トレーへの溶着が発生しないために製品歩
留りが著しく改善される。The two-stage sintering method of the present invention, that is, the primary sintering is performed at the liquid phase crystallization temperature, and then 20 to 20
The magnetic properties of the rare earth permanent magnet obtained by the secondary sintering method at a sintering temperature of 30 ° C. are higher than those of the conventional one-stage sintering method in the coercive force bHC and the squareness ratio ((B
H) max / Br 2 ) is excellent. In addition, the product yield is remarkably improved because neither deformation during welding nor welding to the sintering tray occurs.
【０２９０】[0290]
【図１】 保磁力ｂＨＣとｉＨＣの関係を示す。FIG. 1 shows the relationship between coercive force bHC and iHC.
【図２】 密度、角形比および保磁力ｂＨｃに及ぼす二
次焼結温度の影響を示す。FIG. 2 shows the effects of secondary sintering temperature on density, squareness ratio and coercive force bHc.
【図３】 本発明による二次焼結体を溶体化処理した材
料のミクロ組織を示す。FIG. 3 shows a microstructure of a material obtained by subjecting a secondary sintered body according to the present invention to a solution treatment.
【図４】 従来法による焼結体を溶体化処理した材料の
ミクロ組織を示す。FIG. 4 shows a microstructure of a material obtained by subjecting a sintered body by a conventional method to a solution treatment.
【手続補正書】[Procedure amendment]
【提出日】平成６年９月６日[Submission date] September 6, 1994
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図３[Name of item to be corrected] Figure 3
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図３】本発明による二次焼結体を溶体化処理した材料
のミクロ組織の図面代用写真である。FIG. 3 is a drawing-substitute photograph of a microstructure of a material obtained by subjecting a secondary sintered body according to the present invention to a solution treatment.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図４[Name of item to be corrected] Fig. 4
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図４】従来法による焼結体を溶体化処理した材料のミ
クロ組織の図面代用写真である。FIG. 4 is a drawing-substituting photograph of a microstructure of a material obtained by subjecting a sintered body to a solution treatment by a conventional method.
Claims (2)
土類元素のＳｍ，Ｎｄ，Ｐｒ，Ｙ，Ｃｅの１種以上）、
１０〜２５％のＦｅ、５〜１０％のＣｕ、０．１〜６％
のＭ（ＭはＭｎ，Ｔｉ，Ｚｒ，Ｈｆの１種以上），残部
が実質的にＣｏからなる組成の磁石材料を、液相晶出温
度開始である１１２０〜１２００℃にて一次焼結し、続
いて１１４０〜１２３０℃でかつ前記一次焼結温度より
２０〜３０℃高い温度で二次焼結することを特徴とする
希土類永久磁石の製造方法。1. A weight ratio of 22 to 27% R (wherein R is one or more of rare earth elements Sm, Nd, Pr, Y and Ce),
10-25% Fe, 5-10% Cu, 0.1-6%
Of M (where M is one or more of Mn, Ti, Zr, and Hf) and the balance substantially consists of Co, the primary sintering is performed at 1120 to 1200 ° C., which is the start of the liquid phase crystallization temperature. Then, a method for producing a rare earth permanent magnet, characterized by performing secondary sintering at 1140 to 1230 ° C and at a temperature 20 to 30 ° C higher than the primary sintering temperature.
土類元素のＳｍ，Ｎｄ，Ｐｒ，Ｙ，Ｃｅの１種以上）、
１０〜２５％のＦｅ、５〜１０％のＣｕ、０．５〜６％
のＭ（ＭはＭｎ，Ｔｉ，Ｚｒ，Ｈｆの１種以上）を含有
し，かつこれに０．００３〜０．０１５％のＢ，０．０
０３〜０．０１０％のＰ，０．００３〜０．０１０％の
Ｓの１種又は２種以上を含有し、残部が実質的にＣｏか
らなる組成の磁石材料を、液相晶出開始温度である１１
２０〜１２００℃にて一次焼結し、続いて１１４０〜１
２３０℃でかつ前記一次焼結温度より２０〜３０℃高い
温度で二次焼結することを特徴とする希土類永久磁石の
製造方法。2. A weight ratio of R of 22 to 27% (where R is one or more of rare earth elements Sm, Nd, Pr, Y and Ce),
10-25% Fe, 5-10% Cu, 0.5-6%
Of M (M is one or more of Mn, Ti, Zr, and Hf), and 0.003 to 0.015% B, 0.0
A liquid phase crystallization starting temperature of a magnet material containing 03 to 0.010% of P and 0.003 to 0.010% of S, which is one or two or more, and the balance of which is substantially Co. Is 11
Primary sintering at 20-1200 ° C., followed by 1140-1
A method of manufacturing a rare earth permanent magnet, which comprises performing secondary sintering at a temperature of 230 ° C and 20 to 30 ° C higher than the primary sintering temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3334440A JPH07138672A (en) | 1991-11-22 | 1991-11-22 | Production of rare earth permanent magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3334440A JPH07138672A (en) | 1991-11-22 | 1991-11-22 | Production of rare earth permanent magnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07138672A true JPH07138672A (en) | 1995-05-30 |
Family
ID=18277410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3334440A Pending JPH07138672A (en) | 1991-11-22 | 1991-11-22 | Production of rare earth permanent magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07138672A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09311492A (en) * | 1996-05-23 | 1997-12-02 | Ricoh Co Ltd | Image forming method |
| KR100829986B1 (en) * | 2000-09-19 | 2008-05-16 | 히타치 긴조쿠 가부시키가이샤 | Rare earth magnet and method for manufacturing the same |
| CN102420037A (en) * | 2010-09-24 | 2012-04-18 | 株式会社东芝 | Permanent magnet and motor and generator using the same |
| US20130241682A1 (en) * | 2012-03-15 | 2013-09-19 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| US20130241681A1 (en) * | 2012-03-15 | 2013-09-19 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| GB2584107A (en) * | 2019-05-21 | 2020-11-25 | Vacuumschmelze Gmbh & Co Kg | Sintered R2M17 magnet and method of fabricating a R2M17 magnet |
| US10943716B2 (en) | 2015-09-15 | 2021-03-09 | Kabushiki Kaisha Toshiba | Permanent magnet and rotary electrical machine |
-
1991
- 1991-11-22 JP JP3334440A patent/JPH07138672A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09311492A (en) * | 1996-05-23 | 1997-12-02 | Ricoh Co Ltd | Image forming method |
| KR100829986B1 (en) * | 2000-09-19 | 2008-05-16 | 히타치 긴조쿠 가부시키가이샤 | Rare earth magnet and method for manufacturing the same |
| CN102420037A (en) * | 2010-09-24 | 2012-04-18 | 株式会社东芝 | Permanent magnet and motor and generator using the same |
| US20130241682A1 (en) * | 2012-03-15 | 2013-09-19 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| US20130241681A1 (en) * | 2012-03-15 | 2013-09-19 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| US10573437B2 (en) * | 2012-03-15 | 2020-02-25 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| US10991491B2 (en) * | 2012-03-15 | 2021-04-27 | Kabushiki Kaisha Toshiba | Permanent magnet, and motor and power generator using the same |
| US10943716B2 (en) | 2015-09-15 | 2021-03-09 | Kabushiki Kaisha Toshiba | Permanent magnet and rotary electrical machine |
| GB2584107A (en) * | 2019-05-21 | 2020-11-25 | Vacuumschmelze Gmbh & Co Kg | Sintered R2M17 magnet and method of fabricating a R2M17 magnet |
| GB2584107B (en) * | 2019-05-21 | 2021-11-24 | Vacuumschmelze Gmbh & Co Kg | Sintered R2M17 magnet and method of fabricating a R2M17 magnet |
| US11456095B2 (en) | 2019-05-21 | 2022-09-27 | Vacuumschmelze Gmbh & Co. Kg | Sintered R2M17 magnet and method of fabricating a R2M17 magnet |
| US11837391B2 (en) | 2019-05-21 | 2023-12-05 | Vacuumschmelze Gmbh & Co. Kg | Sintered R2M17 magnet and method of fabricating a R2M17 magnet |
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