TW202308965A - Method of fabricating modified ferrite magnetic powder and ferrite magnet - Google Patents

Method of fabricating modified ferrite magnetic powder and ferrite magnet Download PDF

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TW202308965A
TW202308965A TW110131738A TW110131738A TW202308965A TW 202308965 A TW202308965 A TW 202308965A TW 110131738 A TW110131738 A TW 110131738A TW 110131738 A TW110131738 A TW 110131738A TW 202308965 A TW202308965 A TW 202308965A
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magnetic powder
ferrite magnetic
modified ferrite
manufacturing
mixture
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TWI758224B (en
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黃靖謙
王嘉男
莫智傑
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國立高雄科技大學
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Abstract

A method of fabricating a modified ferrite magnetic powder and a method of fabricating a ferrite magnet are provided. The method of fabricating the modified ferrite magnetic powder includes steps of: providing a mixture; performing a calcination step to form a pre-processed object; performing a coarse pulverization step to form a plurality of coarsely-pulverized particles; performing a fine pulverization step to pulverize the coarsely-pulverized particles into first finely-pulverized particles and second finely-pulverized particles, respectively, wherein an average particle size of the first finely-pulverized particles is between 0.9 and 1 micron, and an average particle size of the second finely-pulverized particles is between 0.5 and 0.6 microns; and mixing the first finely-pulverized particles and the second finely-pulverized particles to obtain the modified ferrite magnetic powder, wherein an average particle size of the modified ferrite magnetic powder is between 0.7 and 0.8 microns.

Description

改質鐵氧體磁粉及磁石的製造方法Modified ferrite magnetic powder and manufacturing method of magnet

本發明係關於一種磁粉與磁石的製造方法,特別是關於一種改質鐵氧體磁粉的製造方法及改質鐵氧體磁石的製造方法。The present invention relates to a manufacturing method of magnetic powder and magnet, in particular to a manufacturing method of modified ferrite magnetic powder and a manufacturing method of modified ferrite magnet.

近年來,隨著電子零部件的小型化、輕量化以及高性能化,對於由氧化物構成的永磁鐵氧體磁體,也不斷要求具有較高的磁氣特性。作為永磁鐵氧體磁體的磁氣特性之指標一般以剩磁(B r)以及矯頑磁力( iH c)作為指標。一直以來,為了達到高剩磁與高矯頑磁力的特性,永磁鐵氧體磁體中的元素成份組成之探討一直在進行著。 In recent years, with the reduction in size, weight and performance of electronic components, permanent ferrite magnets made of oxides have been required to have higher magnetic properties. As the indicators of the magnetic properties of permanent ferrite magnets, remanence (B r ) and coercive force ( i H c ) are generally used as indicators. For a long time, in order to achieve the characteristics of high remanence and high coercive force, the discussion on the composition of elements in permanent ferrite magnets has been going on.

另外,永磁鐵氧體磁體除了具有高剩磁與高矯頑磁力之外,矩形度(Sauareness ratio)也要盡可能的高(矩形度為:在90%的B r的時候,其磁場值(H k)相對於 iH c之比例。即,如果H k/ iH c高的話,則由外部磁場和溫度變化所引起的退磁(Demagnetization)就會比較小,也代表磁體本身的磁場配向度較高,因此能夠得到更穩定的磁氣特性。除此之外,另一個永磁鐵氧體磁體生產上的指標則是需達到減少磁體於磁場成型後之生胚產生裂紋或是燒結製程中磁體出現缺陷機率,以進一步提高永磁鐵氧體磁體量產之良率。然而,現有的永磁鐵氧體磁體的製造方法並無法同時達成上述對於磁氣性質與量產良率的要求。 In addition, permanent ferrite magnets not only have high remanence and high coercive force, but also the rectangularity (Sauareness ratio) should be as high as possible (the rectangularity is: at 90% B r , its magnetic field value ( The ratio of H k ) to i H c . That is, if H k / i H c is high, the demagnetization (Demagnetization) caused by external magnetic field and temperature change will be relatively small, which also represents the magnetic field alignment degree of the magnet itself Higher, so more stable magnetic properties can be obtained. In addition, another permanent ferrite magnet production index is to reduce the cracks of the green body after the magnetic field forming or the sintering process of the magnet Defect probability to further improve the yield rate of mass production of permanent ferrite magnets. However, the existing manufacturing methods of permanent ferrite magnets cannot simultaneously meet the above-mentioned requirements for magnetic properties and mass production yield.

故,有必要提供一種改質鐵氧體磁粉及磁石的製造方法,以解決習用技術所存在的問題。Therefore, it is necessary to provide a method for manufacturing modified ferrite magnetic powder and magnet, so as to solve the problems existing in the conventional technology.

本發明之一目的在於提供一種鐵氧體磁粉及磁石的製造方法,其係利用特定的細粉碎步驟及混合步驟,以使兩種不同平均粒徑的細粉碎顆粒混合,進而降低小於0.1微米的超細微粒(相對於單次細粉碎形成相近粒徑的細粉末而言),以避免或減少鐵氧體磁石中不利於磁特性的非磁性相的生成,並且可增加鐵氧體磁石的良率,進而減少生產成本。One object of the present invention is to provide a manufacturing method of ferrite magnetic powder and magnet, which utilizes a specific finely pulverized step and a mixing step, so that two kinds of finely pulverized particles with different average particle diameters are mixed, thereby reducing the particle size of less than 0.1 micron. Ultrafine particles (compared to fine powders with similar particle sizes formed by single fine pulverization) to avoid or reduce the generation of non-magnetic phases in ferrite magnets that are not conducive to magnetic properties, and can increase the goodness of ferrite magnets. rate, thereby reducing production costs.

為達上述之目的,本發明提供一種改質鐵氧體磁粉的製造方法,其包含步驟:提供一混合物,其中該混合物包含一氧化鐵粉及一鍶化物;進行一煅燒步驟,對該混合物以1260至1300℃之間的溫度持溫達50至70分鐘之間,以形成一前處理物;對該前處理物進行一粗粉碎步驟,以形成多個粗粉碎顆粒,其中以使該些粗粉碎顆粒的一平均粒徑介於2.5至2.7微米之間; 對該些粗粉碎顆粒進行一細粉碎步驟,其中該細粉碎步驟分別將該些粗粉碎顆粒粉碎成第一細粉碎顆粒及第二細粉碎顆粒,其中該第一細粉碎顆粒的一平均粒徑介於0.9至1微米之間,以及該第二細粉碎顆粒的一平均粒徑介於0.5至0.6微米之間;以及混合該第一細粉碎顆粒以及該第二細粉碎顆粒以獲得該改質鐵氧體磁粉,其中該改質鐵氧體磁粉的一平均粒徑介於0.7至0.8微米之間。In order to achieve the above-mentioned purpose, the present invention provides a manufacturing method of modified ferrite magnetic powder, which includes the steps of: providing a mixture, wherein the mixture includes iron oxide powder and a strontium compound; performing a calcining step, the mixture is The temperature between 1260 to 1300° C. is maintained for 50 to 70 minutes to form a pretreatment; the pretreatment is subjected to a coarse pulverization step to form a plurality of coarse pulverization particles, wherein the coarse An average particle size of the crushed particles is between 2.5 and 2.7 microns; a fine crushing step is performed on the coarse crushed particles, wherein the fine crushed step crushes the coarse crushed particles into a first fine crushed particle and a second fine crushed particle respectively. Finely divided particles, wherein an average particle size of the first finely divided particles is between 0.9 and 1 micron, and an average particle size of the second finely divided particles is between 0.5 and 0.6 microns; and mixing the first A finely pulverized particle and the second finely pulverized particle are used to obtain the modified ferrite magnetic powder, wherein an average particle diameter of the modified ferrite magnetic powder is between 0.7 and 0.8 microns.

在本發明之一實施例中,該前處理物的一分子式係SrO.nFe 2O 3,其中n介於5至6之間。 In one embodiment of the present invention, a molecular formula of the pretreatment substance is SrO. nFe 2 O 3 , where n is between 5 and 6.

在本發明之一實施例中,該混合物更包含一鈷化物及一鑭化物中的至少一種。In an embodiment of the invention, the mixture further includes at least one of a cobalt compound and a lanthanum compound.

在本發明之一實施例中,該前處理物的一分子式係(Sr 2+ 1-xLa 3+ x)O.n(Fe 3+ 1-yCo 2+ y) 2O 3,其中n介於5至6之間,x介於0.25至0.3之間,以及y介於0.01至0.02之間。 In one embodiment of the present invention, a molecular formula of the pretreatment substance is (Sr 2+ 1-x La 3+ x )O. n(Fe 3+ 1-y Co 2+ y ) 2 O 3 , wherein n is between 5 and 6, x is between 0.25 and 0.3, and y is between 0.01 and 0.02.

在本發明之一實施例中,在提供該混合物的步驟中,更包含:提供一添加劑,其中該添加劑包含碳酸鈣、氧化矽、五氧化二磷以及氧化硼中的至少一種。In an embodiment of the present invention, the step of providing the mixture further includes: providing an additive, wherein the additive includes at least one of calcium carbonate, silicon oxide, phosphorus pentoxide, and boron oxide.

在本發明之一實施例中,該添加劑包含碳酸鈣及氧化矽,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;以及氧化矽係介於0.2至0.8重量份之間。In one embodiment of the present invention, the additive comprises calcium carbonate and silicon oxide, and based on a total weight of the mixture being 100 parts by weight, calcium carbonate is between 0.5 and 1.5 parts by weight; between 0.2 and 0.8 parts by weight.

在本發明之一實施例中,該添加劑包含碳酸鈣、氧化矽、五氧化二磷以及氧化硼,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;氧化矽係介於0.2至0.8重量份之間;五氧化二磷係大於零且小於等於0.1重量份;以及氧化硼係大於零且小於等於1重量份。In one embodiment of the present invention, the additive comprises calcium carbonate, silicon oxide, phosphorus pentoxide and boron oxide, and based on a total weight of the mixture being 100 parts by weight, calcium carbonate is between 0.5 and 1.5 parts by weight between 0.2 to 0.8 parts by weight of silicon oxide; greater than zero and less than or equal to 0.1 parts by weight of phosphorus pentoxide; and greater than zero and less than or equal to 1 part by weight of boron oxide.

在本發明之一實施例中,在提供該混合物的步驟之後以及進行該煅燒步驟之前更包含對該混合物進行一脫水步驟,其中經該脫水步驟處理後的該混合物的含水率係介於18%至24%之間。In one embodiment of the present invention, after the step of providing the mixture and before the step of calcining, a dehydration step is further included on the mixture, wherein the moisture content of the mixture after the dehydration step is between 18%. to 24%.

在本發明之一實施例中,以該改質鐵氧體磁粉的總重為100wt%,該第一細粉碎顆粉係介於59.5wt%至60.5wt%之間,以及該第二細粉碎顆粒係介於39.5wt%至40.5wt%之間。In one embodiment of the present invention, taking the total weight of the modified ferrite magnetic powder as 100wt%, the first finely pulverized particle powder is between 59.5wt% and 60.5wt%, and the second finely pulverized The particle system is between 39.5wt% and 40.5wt%.

為達上述之目的,本發明提供一種改質鐵氧體磁石的製造方法,其包含步驟:提供一改質鐵氧體磁粉,其中該改質鐵氧體磁粉係通過如上任一實施例所述之改質鐵氧體磁粉的製造方法所製成;對該鐵氧體磁粉進行一磁場配向成型步驟,以形成一胚體,其中該磁場配向成型步驟的一配向磁場強度係介於1.3至1.7特斯拉之間,一成型壓力係介於3至4噸/平方公分之間,以及一成型時間係介於90至110秒之間;以及進行一燒結步驟,對該胚體以介於1220至1240℃之間的溫度持續燒結達50至70分鐘之間,以製得一鐵氧體磁石。In order to achieve the above-mentioned purpose, the present invention provides a method for manufacturing a modified ferrite magnet, which includes the steps of: providing a modified ferrite magnetic powder, wherein the modified ferrite magnetic powder is passed through any one of the above embodiments. Made by the manufacturing method of the modified ferrite magnetic powder; the ferrite magnetic powder is subjected to a magnetic field alignment forming step to form an embryo body, wherein the strength of an alignment magnetic field in the magnetic field alignment forming step is between 1.3 and 1.7 Between Tesla, a molding pressure is between 3 to 4 tons per square centimeter, and a molding time is between 90 to 110 seconds; and a sintering step is performed to the green body at 1220 Sintering is continued at a temperature between 1240° C. for between 50 and 70 minutes to produce a ferrite magnet.

為了讓本發明之上述及其他目的、特徵、優點能更明顯易懂,下文將特舉本發明較佳實施例,並配合所附圖式,作詳細說明如下。再者,本發明所提到的方向用語,例如上、下、頂、底、前、後、左、右、內、外、側面、周圍、中央、水平、橫向、垂直、縱向、軸向、徑向、最上層或最下層等,僅是參考附加圖式的方向。因此,使用的方向用語是用以說明及理解本發明,而非用以限制本發明。In order to make the above and other objects, features, and advantages of the present invention more comprehensible, preferred embodiments of the present invention will be exemplified below in detail together with the attached drawings. Furthermore, the directional terms mentioned in the present invention are, for example, up, down, top, bottom, front, back, left, right, inside, outside, side, surrounding, central, horizontal, transverse, vertical, longitudinal, axial, The radial direction, the uppermost layer or the lowermost layer, etc. are only directions referring to the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

請參照第1圖所示,本發明一實施例之改質鐵氧體磁粉的製造方法10主要包含下列步驟11至15:提供一混合物,其中該混合物包含一氧化鐵粉及一鍶化物(步驟11);進行一煅燒步驟,對該混合物以1260至1300℃之間的溫度持溫達50至70分鐘之間,以形成一前處理物(步驟12);對該前處理物進行一粗粉碎步驟,以形成多個粗粉碎顆粒,其中以使該些粗粉碎顆粒的一平均粒徑介於2.5至2.7微米之間(步驟13);對該些粗粉碎顆粒進行一細粉碎步驟,其中該細粉碎步驟分別將該些粗粉碎顆粒粉碎成第一細粉碎顆粒及第二細粉碎顆粒,其中該第一細粉碎顆粒的一平均粒徑介於0.9至1微米之間,以及該第二細粉碎顆粒的一平均粒徑介於0.5至0.6微米之間(步驟14);以及混合該第一細粉碎顆粒以及該第二細粉碎顆粒以獲得該改質鐵氧體磁粉,其中該改質鐵氧體磁粉的一平均粒徑介於0.7至0.8微米之間(步驟15)。本發明將於下文逐一詳細說明實施例之上述各步驟的實施細節及其原理。Please refer to Fig. 1, the manufacturing method 10 of modified ferrite magnetic powder according to an embodiment of the present invention mainly includes the following steps 11 to 15: a mixture is provided, wherein the mixture includes iron oxide powder and a strontium compound (step 11); Carrying out a calcination step, keeping the mixture at a temperature between 1260 and 1300° C. for 50 to 70 minutes to form a pretreatment (step 12); coarsely pulverizing the pretreatment step, to form a plurality of coarsely pulverized particles, wherein an average particle size of the coarsely pulverized particles is between 2.5 and 2.7 microns (step 13); a finely pulverized step is performed on the coarsely pulverized particles, wherein the The fine crushing step crushes the coarsely crushed particles into first finely crushed particles and second finely crushed particles, wherein an average particle diameter of the first finely crushed particles is between 0.9 and 1 micron, and the second finely crushed particles an average particle diameter of the crushed particles is between 0.5 and 0.6 microns (step 14); and mixing the first finely crushed particles and the second finely crushed particles to obtain the modified ferrite magnetic powder, wherein the modified iron An average particle size of the oxygen magnetic powder is between 0.7 and 0.8 microns (step 15). The present invention will describe in detail the implementation details and principles of the above-mentioned steps of the embodiments one by one below.

本發明一實施例之改質鐵氧體磁粉的製造方法10首先係步驟11:提供一混合物,其中該混合物包含一氧化鐵粉及一鍶化物。在本步驟11中,該氧化鐵粉例如可以是一市售產品,亦可以是一鋼鐵製程中所產生的副產品,例如鋼鐵在進行熱加工時需將鐵表面所生成的鐵銹去除,而該鐵銹可作為該氧化鐵粉的來源。在一實施例中,該鍶化物例如可包含碳酸鍶。值得一提的是,所提供的該混合物主要用於生成鍶系鐵氧體磁粉。The manufacturing method 10 of the modified ferrite magnetic powder according to an embodiment of the present invention starts with step 11: providing a mixture, wherein the mixture includes iron oxide powder and a strontium compound. In this step 11, the iron oxide powder can be, for example, a commercially available product, or it can be a by-product produced in a steel manufacturing process. It can be used as the source of the iron oxide powder. In one embodiment, the strontium compound may include strontium carbonate, for example. It is worth mentioning that the provided mixture is mainly used to produce strontium ferrite magnetic powder.

在一實施例中,在提供該混合物的步驟11中,還可提供一添加劑,其中該添加劑包含碳酸鈣(CaCO 3)、氧化矽(SiO 2)、五氧化二磷(P 2O 5)以及氧化硼(B 2O 3)中的至少一種。以下說明各種添加劑的效果,其中所涉及的重量百分比皆是以該混合物的總重為100重量份計為基準。在一實施例中,該添加劑可在粉碎步驟中加入至球磨機中。 In one embodiment, in step 11 of providing the mixture, an additive may also be provided, wherein the additive includes calcium carbonate (CaCO 3 ), silicon oxide (SiO 2 ), phosphorus pentoxide (P 2 O 5 ) and At least one of boron oxide (B 2 O 3 ). The effects of various additives are described below, wherein the weight percentages involved are based on the total weight of the mixture being 100 parts by weight. In one embodiment, the additive can be added to the ball mill during the pulverization step.

碳酸鈣是一種用於促進晶粒成長的元素,於本發明中碳酸鈣之添加量例如介於0.5至1.5重量份之間,當碳酸鈣添加量過多的時候(例如大於1.5重量份),後續形成鐵氧體磁石所進行的燒結步驟中,會發生過量的晶粒增長,而導致矯頑磁力的降低。另一方面,當加入的碳酸鈣之添加量過少的時候(例如小於0.5重量份),晶粒增長的現象會被過度抑制,進而導致與晶粒增長同時發生的取向的提高不足,最終導致剩磁(B r)低落。 Calcium carbonate is a kind of element that is used to promote grain growth, and the addition amount of calcium carbonate in the present invention is for example between 0.5 to 1.5 weight part, when calcium carbonate addition time is too much (for example greater than 1.5 weight part), follow-up During the sintering step to form ferrite magnets, excessive grain growth occurs, resulting in a decrease in coercive force. On the other hand, when the amount of calcium carbonate added is too small (for example, less than 0.5 parts by weight), the phenomenon of grain growth will be excessively suppressed, which will lead to insufficient improvement of the orientation that occurs simultaneously with grain growth. Magnetism (B r ) is low.

氧化矽之添加則是用來消除燒結時的晶粒增長,本發明中之氧化矽的添加量例如介於0.2至0.8重量份之間。當加入的氧化矽過少時(例如小於0.2重量份),在燒結階段會發生過量的晶粒增長,而導致矯頑磁力降低。當加入的氧化矽過多時(例如大於0.8重量份),在燒結階段之晶粒增長會過度消除,而導致與晶粒增長同時發生的取向之改進不足,最終而導致剩磁(B r)的下降。 The addition of silicon oxide is used to eliminate grain growth during sintering, and the amount of silicon oxide in the present invention is, for example, between 0.2 and 0.8 parts by weight. When the amount of silicon oxide added is too small (for example, less than 0.2 parts by weight), excessive grain growth will occur during the sintering stage, resulting in a decrease in the coercive force. When too much silicon oxide is added (for example, more than 0.8 parts by weight), the grain growth in the sintering stage will be eliminated excessively, resulting in insufficient improvement of the orientation that occurs simultaneously with the grain growth, and finally leads to the loss of remanence (B r ) decline.

五氧化二磷之添加可提高矩形度(H k/ iH c)、剩磁(B r)及矯頑磁力( iH c)。本發明中之五氧化二磷的添加量例如可以是大於零且小於等於0.1重量份。若是未介於前述範圍,則無法提高前述的磁力性質。 The addition of phosphorus pentoxide can improve squareness (H k / i H c ), remanence (B r ) and coercivity ( i H c ). The amount of phosphorus pentoxide added in the present invention can be, for example, greater than zero and less than or equal to 0.1 parts by weight. If it is not within the aforementioned range, the aforementioned magnetic properties cannot be improved.

氧化硼之添加是為了可降低在製得由永磁鐵氧體磁體構成的燒結磁體時之燒結溫度且同時能提高剩磁(B r)、矯頑磁力( iH c),本發明中之氧化硼添加量例如是大於零且小於等於1重量份。若是未介於前述範圍,則無法提高前述的磁力性質。 The addition of boron oxide is to reduce the sintering temperature when making a sintered magnet made of permanent ferrite magnets and at the same time increase the remanence (B r ) and coercive force ( i H c ). The oxidation in the present invention The amount of boron added is, for example, greater than zero and less than or equal to 1 part by weight. If it is not within the aforementioned range, the aforementioned magnetic properties cannot be improved.

在一實施例中,該添加劑包含碳酸鈣及氧化矽,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;以及氧化矽係介於0.2至0.8重量份之間。在另一實施例中,該添加劑包含碳酸鈣、氧化矽、五氧化二磷以及氧化硼,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;氧化矽係介於0.2至0.8重量份之間;五氧化二磷係大於零且小於等於0.1重量份;以及氧化硼係大於零且小於等於1重量份。In one embodiment, the additive includes calcium carbonate and silicon oxide, and based on a total weight of the mixture of 100 parts by weight, the calcium carbonate is between 0.5 and 1.5 parts by weight; and the silicon oxide is between 0.2 and 1.5 parts by weight. Between 0.8 parts by weight. In another embodiment, the additive comprises calcium carbonate, silicon oxide, phosphorus pentoxide and boron oxide, and based on a total weight of the mixture of 100 parts by weight, calcium carbonate is between 0.5 and 1.5 parts by weight ; silicon oxide is between 0.2 and 0.8 parts by weight; phosphorus pentoxide is greater than zero and less than or equal to 0.1 parts by weight; and boron oxide is greater than zero and less than or equal to 1 part by weight.

本發明一實施例之改質鐵氧體磁粉的製造方法10接著係步驟12:進行一煅燒步驟,對該混合物以1260至1300℃之間的溫度持溫達50至70分鐘之間,以形成一前處理物。在本步驟12中,該煅燒步驟主要用於使該混合物在高溫反應,進行使該前處理物符合鍶系鐵氧體磁粉的分子式。在一實施例中,該前處理物的一分子式係SrO.nFe 2O 3,其中n介於5至6之間。在另一實施例中,進行該煅燒步驟處理時的一氣氛係包含5%的氧氣。 The manufacturing method 10 of modified ferrite magnetic powder according to an embodiment of the present invention is followed by step 12: a calcination step is performed, and the mixture is kept at a temperature between 1260 and 1300 °C for 50 to 70 minutes to form a pre-processing substance. In this step 12, the calcination step is mainly used to react the mixture at high temperature to make the pre-treated product conform to the molecular formula of the strontium-based ferrite magnetic powder. In one embodiment, a molecular formula of the pretreatment is SrO. nFe 2 O 3 , where n is between 5 and 6. In another embodiment, the calcining step is performed in an atmosphere comprising 5% oxygen.

在一實施例中,該混合物還可包含一鈷化物及一鑭化物中的至少一種。具體而言,鈷化物中的鈷元素或是該鑭化物中的鑭元素,其皆有助於改質鐵氧體磁粉所製成的永磁鐵氧體磁石得到更高的剩磁(B r)、矯頑磁力( iH c)和矩形度(H k/ iH c)。在一範例中,該鈷化物例如是氧化鈷(Co 3O 4)。在另一範例中,該鑭化物例如是氧化鑭(La 2O 3)。在本實施例中,該混合物經煅燒步驟後所形成的該前處理物的一分子式係(Sr 2+ 1-xLa 3+ x)O.n(Fe 3+ 1-yCo 2+ y) 2O 3,其中,其中n介於5至6之間,x介於0.25至0.3之間,以及y介於0.01至0.02之間。在一實施例中,鈷化物可在後述的粉碎步驟中加入。 In one embodiment, the mixture may further include at least one of a cobalt compound and a lanthanum compound. Specifically, the cobalt element in the cobalt compound or the lanthanum element in the lanthanide compound are both helpful to modify the permanent ferrite magnet made of ferrite powder to obtain higher remanence (B r ) , coercivity ( i H c ) and squareness (H k / i H c ). In one example, the cobalt compound is cobalt oxide (Co 3 O 4 ). In another example, the lanthanide is, for example, lanthanum oxide (La 2 O 3 ). In this embodiment, a molecular formula of the pretreated product formed after the mixture is calcined is (Sr 2+ 1-x La 3+ x )O. n(Fe 3+ 1-y Co 2+ y ) 2 O 3 , wherein n is between 5 and 6, x is between 0.25 and 0.3, and y is between 0.01 and 0.02. In one embodiment, the cobalt compound can be added in the crushing step described later.

在一實施例中,在提供該混合物的步驟11之後以及進行該煅燒步驟12之前更包含對該混合物進行一脫水步驟,其中經該脫水步驟處理後的該混合物的含水率係介於18%至24%之間。In one embodiment, after the step 11 of providing the mixture and before performing the calcining step 12, a dehydration step is further included on the mixture, wherein the moisture content of the mixture after the dehydration step is between 18% and Between 24%.

本發明一實施例之改質鐵氧體磁粉的製造方法10接著係步驟13:對該前處理物進行一粗粉碎步驟,以形成多個粗粉碎顆粒,其中以使該些粗粉碎顆粒的一平均粒徑介於2.5至2.7微米之間。在本步驟13中,將該前處理物粉碎至平均粒徑約達2.6微米左右。The manufacturing method 10 of modified ferrite magnetic powder according to an embodiment of the present invention is followed by step 13: performing a coarse crushing step on the pre-treated material to form a plurality of coarsely crushed particles, wherein one of the coarsely crushed particles is The average particle size is between 2.5 and 2.7 microns. In this step 13, the pretreated material is pulverized until the average particle size reaches about 2.6 microns.

本發明一實施例之改質鐵氧體磁粉的製造方法10接著係步驟14:對該些粗粉碎顆粒進行一細粉碎步驟,其中該細粉碎步驟分別將該些粗粉碎顆粒粉碎成第一細粉碎顆粒及第二細粉碎顆粒,其中該第一細粉碎顆粒的一平均粒徑介於0.9至1微米之間,以及該第二細粉碎顆粒的一平均粒徑介於0.5至0.6微米之間。在本步驟14中,主要是將該些粗粉碎顆粒粉碎成兩種不同的平均粒徑。具體的,第一細粉碎顆粒之功能性在於能夠儘可能地降低混合後之整體瓷漿內部粒子徑<0.1μm之過細磁粉比例,有助於提升濕式磁場成型所需瓷漿之成型性、成型良率及整體良率。第二細粉碎顆粒有別於第一細粉碎顆粒,其功能在於能進一步提升燒結後磁石內部之單磁區晶粒比例,對於磁石整體磁特性可起到明顯助益。The manufacturing method 10 of the modified ferrite magnetic powder according to an embodiment of the present invention is followed by step 14: performing a fine crushing step on the coarsely crushed particles, wherein the fine crushing step crushes the coarsely crushed particles into a first fine crushing step. Pulverized particles and second finely pulverized particles, wherein an average particle size of the first finely pulverized particles is between 0.9 and 1 micron, and an average particle size of the second finely pulverized particles is between 0.5 and 0.6 microns . In this step 14, the coarsely pulverized particles are mainly pulverized into two different average particle sizes. Specifically, the functionality of the first finely pulverized particles lies in the ability to reduce the proportion of ultra-fine magnetic powder with an internal particle diameter of <0.1 μm in the mixed overall porcelain slurry as much as possible, which helps to improve the formability of the porcelain slurry required for wet magnetic field molding. Molding yield and overall yield. The second finely pulverized particles are different from the first finely pulverized particles, and its function is to further increase the ratio of single magnetic domain crystal grains inside the sintered magnet, which can significantly benefit the overall magnetic properties of the magnet.

在一實施例中,第一細粉碎顆粒例如是球磨機(Ball Mill)以料球重量比為1:12,磁粉漿料固含量約35~37%,轉速約為40rpm,濕式研磨3~4小時,進一步細化後出料得到第一細粉碎顆粒,以使第一細粉碎顆粒的平均粒徑(或稱平均磁粉粒度(D 50))達到0.95±0.05μm (例如可通過市售的費氏粒徑分析儀測得之窄單峰粒徑分佈。其中,鋼球可以是約為直徑Φ4.76mm的無鉻軸承鋼球。 In one embodiment, the first finely pulverized particles are, for example, a ball mill (Ball Mill) with a ball weight ratio of 1:12, a magnetic powder slurry with a solid content of about 35-37%, a rotational speed of about 40 rpm, and wet grinding of 3-4 hours, after further refinement, the discharge obtains the first finely crushed particles, so that the average particle diameter (or the average magnetic powder particle size (D 50 )) of the first finely crushed particles reaches 0.95 ± 0.05 μm (for example, it can be obtained through commercially available The narrow unimodal particle size distribution measured by the particle size analyzer.Wherein, the steel ball can be a chrome-free bearing steel ball with a diameter of about Φ4.76mm.

在一實施例中,第二細粉碎顆粒例如是球磨機(Ball Mill)以料球重量比為1:12,磁粉漿料固含量約35~37%,轉速約為40rpm,濕式研磨9~10小時,進一步細化後出料得到第一細粉碎顆粒,以使第二細粉碎顆粒的平均粒徑(或稱平均磁粉粒度(D 50))達到0.55±0.05μm (例如可通過市售的費氏粒徑分析儀測得之窄單峰粒徑分佈。其中,鋼球可以是約為直徑Φ4.76mm的無鉻軸承鋼球。 In one embodiment, the second finely pulverized particles are, for example, a ball mill (Ball Mill) with a ball weight ratio of 1:12, a magnetic powder slurry with a solid content of about 35-37%, a rotational speed of about 40 rpm, and wet grinding of 9-10 hour, after further refinement, the discharge obtains the first finely crushed particles, so that the average particle diameter (or the average magnetic powder particle size (D 50 )) of the second finely crushed particles reaches 0.55 ± 0.05 μm (for example, it can be obtained through a commercially available fee The narrow unimodal particle size distribution measured by the particle size analyzer.Wherein, the steel ball can be a chrome-free bearing steel ball with a diameter of about Φ4.76mm.

本發明一實施例之改質鐵氧體磁粉的製造方法10接著係步驟15:混合該第一細粉碎顆粒以及該第二細粉碎顆粒以獲得該改質鐵氧體磁粉,其中該改質鐵氧體磁粉的一平均粒徑介於0.7至0.8微米之間。在本步驟15中,主要是通過混合的方式來形成平均粒徑介於0.7至0.8微米之間的改質鐵氧體磁粉。在一實施例中,以該改質鐵氧體磁粉的總重為100wt%,該第一細粉碎顆粉係介於59.5wt%至60.5wt%之間,以及該第二細粉碎顆粒係介於39.5wt%至40.5wt%之間。The manufacturing method 10 of modified ferrite magnetic powder according to an embodiment of the present invention is followed by step 15: mixing the first finely pulverized particles and the second finely pulverized particles to obtain the modified ferrite magnetic powder, wherein the modified iron An average particle size of the oxygen magnetic powder is between 0.7 and 0.8 microns. In this step 15 , the modified ferrite magnetic powder with an average particle size between 0.7 and 0.8 μm is mainly formed by mixing. In one embodiment, taking the total weight of the modified ferrite magnetic powder as 100wt%, the first finely pulverized particle powder is between 59.5wt% and 60.5wt%, and the second finely pulverized particle is between 59.5wt% and 60.5wt%. Between 39.5wt% and 40.5wt%.

這種作法不同於傳統方法。具體而言,傳統方法通常是使用經細粉碎步驟的單一種平均粒徑的鐵氧體磁粉,例如,單純將粗粉碎顆粒直接研磨至平均粒徑介於0.7至0.8微米之間的細粉碎顆粒。這種作法雖然可以得到目標平均粒徑,但是這種作法會導致超微細粉(例如小於0.1微米的粒徑)的增加,反而導致產品的良率下降,並且產品的磁特性差(相關的實驗佐證在後面段落描述)。反之,本發明是利用混合的方式來將兩種粒徑的細粉碎顆粒形成改質鐵氧體磁粉,其可具有較少的超微細粉(相關的實驗佐證在後面段落描述)。This approach is different from traditional methods. Specifically, the traditional method usually uses ferrite magnetic powder with a single average particle size that has been finely pulverized, for example, simply grinding coarsely pulverized particles directly to finely pulverized particles with an average particle size between 0.7 and 0.8 microns . Although this approach can obtain the target average particle size, this approach will lead to an increase in ultra-fine powder (such as a particle size less than 0.1 micron), which will instead lead to a decline in the yield of the product, and the poor magnetic properties of the product (related experiments The supporting evidence is described in the following paragraphs). On the contrary, the present invention uses a mixing method to form finely pulverized particles of two particle sizes into a modified ferrite magnetic powder, which can have less ultrafine powder (relevant experimental evidence is described in the following paragraphs).

這邊要提到的是,一般而言,該改質鐵氧體磁粉的平均粒徑越小,磁氣特性越佳。但是,該改質鐵氧體磁粉中粒徑過小的部分(即上述的細微顆粒)反而有害於磁氣特性與成型良率。具體而言,粒徑過小的部分的該改質鐵氧體磁粉容易在後續燒結步驟中產生非磁性相,進而有害於磁氣特性。另一方面,在後續磁場配向成型步驟中通常會使用一模具,以使該改質鐵氧體磁粉形成預定的形狀。該模具上通常會開設有多個小孔洞,以使該改質鐵氧體磁粉中的水份在加壓時流出。然而,該改質鐵氧體磁粉中粒徑過小的部分會在加壓過程中阻塞該些小孔洞,導致需以更大的壓力才能完成磁場配向成型步驟,導致胚體中形成較大的應力進而產生裂紋或是於燒結後產生缺陷。因此,通過上述特定參數的細粉碎步驟及混合步驟,進而減少或避免上述的問題。It should be mentioned here that, generally speaking, the smaller the average particle size of the modified ferrite magnetic powder, the better the magnetic properties. However, the portion of the modified ferrite magnetic powder whose particle size is too small (that is, the above-mentioned fine particles) is detrimental to the magnetic properties and molding yield. Specifically, the portion of the modified ferrite magnetic powder with too small a particle size tends to generate a non-magnetic phase in a subsequent sintering step, thereby detrimental to magnetic properties. On the other hand, a mold is usually used in the subsequent magnetic field alignment forming step to form the modified ferrite magnetic powder into a predetermined shape. Usually, a plurality of small holes are opened on the mold to allow the water in the modified ferrite magnetic powder to flow out when pressurized. However, the part with too small particle size in the modified ferrite magnetic powder will block the small holes during the pressurization process, resulting in the need for greater pressure to complete the magnetic field alignment forming step, resulting in the formation of greater stress in the green body. Cracks or defects after sintering. Therefore, the above-mentioned problems can be further reduced or avoided by the finely pulverizing step and the mixing step with the above-mentioned specific parameters.

請參照第2圖,本發明另一實施例提出一種改質鐵氧體磁石的製造方法20,其包含步驟21至23:提供一改質鐵氧體磁粉,其中該改質鐵氧體磁粉係如上所述任一實施例的改質鐵氧體磁粉的製造方法所製成(步驟21);對該改質鐵氧體磁粉進行一磁場配向成型步驟,以形成一胚體,其中該磁場配向成型步驟的一配向磁場強度係介於1.3至1.7特斯拉之間,一成型壓力係介於3至4噸/平方公分之間,以及一成型時間係介於90至110秒之間(步驟22);以及進行一燒結步驟,對該胚體以介於1220至1240℃之間的溫度持續燒結達50至70分鐘之間,以製得該鐵氧體磁石(步驟23)。Please refer to FIG. 2 , another embodiment of the present invention proposes a manufacturing method 20 of a modified ferrite magnet, which includes steps 21 to 23: providing a modified ferrite magnetic powder, wherein the modified ferrite magnetic powder is The modified ferrite magnetic powder produced by the manufacturing method of any of the above embodiments (step 21); the modified ferrite magnetic powder is subjected to a magnetic field alignment forming step to form a green body, wherein the magnetic field alignment An alignment magnetic field strength of the molding step is between 1.3 to 1.7 Tesla, a molding pressure is between 3 to 4 tons/cm2, and a molding time is between 90 to 110 seconds (step 22); and performing a sintering step of continuously sintering the green body at a temperature between 1220-1240° C. for 50-70 minutes to obtain the ferrite magnet (step 23 ).

本發明將於下文逐一詳細說明實施例之上述各步驟的實施細節及其原理。The present invention will describe in detail the implementation details and principles of the above-mentioned steps of the embodiments one by one below.

本發明一實施例之改質鐵氧體磁石的製造方法20首先係步驟21:提供一改質鐵氧體磁粉,其中該改質鐵氧體磁粉係如上所述任一實施例的改質鐵氧體磁粉的製造方法所製成。在本步驟21中,通過上述的改質鐵氧體磁粉的製造方法10製成該改質鐵氧體磁粉。The manufacturing method 20 of a modified ferrite magnet according to an embodiment of the present invention is first step 21: providing a modified ferrite magnetic powder, wherein the modified ferrite magnetic powder is the modified iron according to any embodiment as described above Oxygen magnetic powder is made by the manufacturing method. In this step 21 , the modified ferrite magnetic powder is produced through the above-mentioned manufacturing method 10 of the modified ferrite magnetic powder.

本發明一實施例之改質鐵氧體磁石的製造方法20接著係步驟22:對該改質鐵氧體磁粉進行一磁場配向成型步驟,以形成一胚體,其中該磁場配向成型步驟的一配向磁場強度係介於1.3至1.7特斯拉之間,一成型壓力係介於3至4噸/平方公分之間,以及一成型時間係介於90至110秒之間。在本步驟22中,主要是提供成型壓力與配向磁場,以使該改質鐵氧體磁粉成型為預定的形狀並且具有預定的磁場方向。這邊要提到的是,由於使用改質鐵氧體磁粉的製造方法10製成的該改質鐵氧體磁粉,故可使用較低的成型時間即可成型為胚體,並且具有較高的良率。The manufacturing method 20 of the modified ferrite magnet according to an embodiment of the present invention is followed by step 22: performing a magnetic field alignment forming step on the modified ferrite magnetic powder to form a green body, wherein a step of the magnetic field alignment forming step The alignment magnetic field strength is between 1.3-1.7 Tesla, a forming pressure is between 3-4 tons/cm2, and a forming time is between 90-110 seconds. In this step 22, the molding pressure and the alignment magnetic field are mainly provided, so that the modified ferrite magnetic powder is molded into a predetermined shape and has a predetermined magnetic field direction. It should be mentioned here that since the modified ferrite magnetic powder produced by the manufacturing method 10 of the modified ferrite magnetic powder can be formed into a green body with a relatively low molding time, and has a high yield rate.

本發明一實施例之改質鐵氧體磁石的製造方法20最後係步驟23:進行一燒結步驟,對該胚體以介於1220至1240℃之間的溫度持續燒結達50至70分鐘之間,以製得該鐵氧體磁石。在本步驟23中,主要是通過燒結步驟以使該胚體中的水份去除以製得一鐵氧體磁石。The manufacturing method 20 of the modified ferrite magnet according to an embodiment of the present invention is the last step 23: a sintering step is performed, and the green body is continuously sintered at a temperature between 1220 and 1240° C. for 50 to 70 minutes. , to make the ferrite magnet. In this step 23 , the moisture in the green body is mainly removed through a sintering step to produce a ferrite magnet.

這邊要提到的是,由於本發明實施例之改質鐵氧體磁石的製造方法20使用本發明實施例之改質鐵氧體磁粉的製造方法所製得的改質鐵氧體磁粉,其中該改質鐵氧體磁粉中的粒徑過小的部分較少。因此,在燒結步驟中不易產生非磁性相,並且在磁場配向成型步驟中也不易產生阻塞的問題,故可提高磁氣性質以及良率。It should be mentioned here that since the modified ferrite magnet manufacturing method 20 of the embodiment of the present invention uses the modified ferrite magnetic powder obtained by the manufacturing method of the modified ferrite magnetic powder of the embodiment of the present invention, Among them, the portion of the modified ferrite magnetic powder in which the particle diameter is too small is relatively small. Therefore, it is not easy to produce non-magnetic phase in the sintering step, and it is not easy to generate blocking problem in the magnetic field alignment forming step, so the magnetic properties and yield can be improved.

以下舉出數個實施例與比較例,以說明本發明實施例之改質鐵氧體磁粉的製造方法及本發明實施例之改質鐵氧體磁石的製造方法所製得的鐵氧體磁石確實具有上述的效果。Several examples and comparative examples are given below to illustrate the ferrite magnets produced by the method of manufacturing modified ferrite magnetic powder of the embodiment of the present invention and the method of manufacturing modified ferrite magnet of the embodiment of the present invention Indeed, it has the above-mentioned effect.

實施例1Example 1

首先,將主原料氧化鐵粉(Fe 2O 3)與另一種主原料碳酸鍶(SrCO 3)以SrO·nFe 2O 3(n=5.9)之基本組成進行配料,另同時加入4.9wt%的微量添加劑La 2O 3及水進行混合後,以料球重量比為1:5的市售球磨機(Ball Mill)混磨2小時後出料得到漿料狀態的混合物,鋼球為直徑3/16英吋的無鉻軸承鋼球。接著,將上述的混合物以市售空氣壓濾機進行脫水,脫水後的混合物的含水率約21±3%。 Firstly, mix iron oxide powder (Fe 2 O 3 ) as the main raw material and strontium carbonate (SrCO 3 ) as the main raw material with the basic composition of SrO·nFe 2 O 3 (n=5.9), and add 4.9wt% of After mixing a small amount of additive La2O3 and water, mix and grind for 2 hours with a commercially available ball mill (Ball Mill) with a ball weight ratio of 1:5 , and then discharge to obtain a mixture in a slurry state. The steel ball is 3/16 in diameter Inch chrome-free bearing steel balls. Next, the above mixture is dehydrated with a commercially available air filter press, and the moisture content of the dehydrated mixture is about 21±3%.

接著,將脫水後的混合物進行煅燒步驟。以一市售烘乾機對該混合物進行預熱,其中烘乾機之溫度為300±10 oC,持溫時間為30至40分鐘,經過烘乾後的混合物含水率小於2%。之後,將該混合物放入一市售旋窯進行煅燒以形成一前處理物,煅燒溫度為1280±20 oC,煅燒時間為1小時,且煅燒時旋窯內之氧氣含量約5%。 Next, the dehydrated mixture is subjected to a calcination step. Preheat the mixture with a commercially available dryer, wherein the temperature of the dryer is 300±10 o C, and the temperature holding time is 30 to 40 minutes. The moisture content of the dried mixture is less than 2%. Afterwards, put the mixture into a commercially available rotary kiln for calcination to form a pretreated product. The calcination temperature is 1280±20 o C, the calcination time is 1 hour, and the oxygen content in the rotary kiln is about 5% during calcination.

將經過旋窯煅燒之前處理物通過與旋窯相連結的溜管送入冷卻桶中進行冷卻。在前處理物的溫度降至90 oC以下時,通過裝置有旋風收集器之風選功能的松永式球磨機(Roller Mill)進行粗粉碎步驟,以使該些粗粉碎顆粒的平均粒徑約為2.5~2.7微米(例如約2.6微米)之窄單峰粒徑分佈。 The treated material before being calcined in the rotary kiln is sent into the cooling barrel through the chute connected with the rotary kiln for cooling. When the temperature of the pre-treated material drops below 90 o C, the rough pulverization step is carried out by a Matsunaga-type ball mill (Roller Mill) equipped with a wind separation function of a cyclone collector, so that the average particle size of the coarse pulverized particles is about Narrow unimodal particle size distribution of 2.5-2.7 microns (eg about 2.6 microns).

之後,以上述的該混合物的總重為100重量份計,再加入各個組成物,包含1.5重量份的Co 3O 4、1.0重量份的CaCO 3、0.4重量份的SiO 2、0.03重量份的P 2O 5及0.05重量份的B 2O 3至球磨機中,於球磨機(Ball Mill)以料球重量比為1:12,磁粉漿料固含量約35~37%,轉速約為40rpm,鋼球是約為直徑Φ4.76mm的無鉻軸承鋼球,並分別以濕式研磨3~4以及9~10小時進行細粉碎步驟,以分別得到第一細粉碎顆粒及第二細粉碎顆粒,其中第一細粉碎顆粒的平均粒徑(或稱平均磁粉粒度(D 50))達到0.95±0.05μm (例如可通過市售的費氏粒徑分析儀測得之窄單峰粒徑分佈),第二細粉碎顆粒的平均粒徑(或稱平均磁粉粒度(D 50))達到0.55±0.05μm (例如可通過市售的費氏粒徑分析儀測得之窄單峰粒徑分佈。之後,再將第一細粉碎顆粒及第二細粉碎顆粒混合以形成該改質鐵氧體磁粉,其中以該改質鐵氧體磁粉的總重為100wt%,該第一細粉碎顆粉係介於59.5wt%至60.5wt%之間,以及該第二細粉碎顆粒係介於39.5wt%至40.5wt%之間,該改質鐵氧體磁粉的平均粒徑約為0.7至0.8微米之間(例如約0.75微米)。 Afterwards, based on the total weight of the above-mentioned mixture being 100 parts by weight, various components were added, including 1.5 parts by weight of Co 3 O 4 , 1.0 parts by weight of CaCO 3 , 0.4 parts by weight of SiO 2 , and 0.03 parts by weight of P 2 O 5 and 0.05 parts by weight of B 2 O 3 are put into the ball mill. In the ball mill (Ball Mill), the weight ratio of the material to the ball is 1:12, the solid content of the magnetic powder slurry is about 35~37%, and the rotation speed is about 40rpm. The ball is a chromium-free bearing steel ball with a diameter of Φ4.76mm, and the fine crushing step is carried out by wet grinding for 3~4 hours and 9~10 hours respectively to obtain the first finely crushed particles and the second finely crushed particles, wherein The average particle size of the first finely pulverized particles (or average magnetic powder particle size (D 50 )) reaches 0.95±0.05 μm (for example, a narrow unimodal particle size distribution that can be measured by a commercially available Fischer particle size analyzer), and the first 2. The average particle diameter of the finely pulverized particles (or the average magnetic powder particle size (D 50 )) reaches 0.55 ± 0.05 μm (such as a narrow unimodal particle size distribution that can be measured by a commercially available Fischer particle size analyzer. After that, The first finely pulverized particles and the second finely pulverized particles are mixed to form the modified ferrite magnetic powder, wherein the total weight of the modified ferrite magnetic powder is 100wt%, and the first finely pulverized particle powder is between 59.5 wt% to 60.5wt%, and the second finely pulverized particles are between 39.5wt% to 40.5wt%, the average particle size of the modified ferrite magnetic powder is about 0.7 to 0.8 microns (for example about 0.75 microns).

接著,進行(濕式)磁場配向成型步驟,使用市售的25噸之半自動濕式磁場成型機,對該改質鐵氧體磁粉進行20顆胚體的磁場配向成型,配向磁場強度為1.5特斯拉(Tesla),成型壓力為3.5噸/平方公分(Ton/cm 2),成型胚件尺寸為Φ26.5、厚度約13mm之圓胚。於實施例1中,經成型20顆胚體之平均所需濕式磁場成型時間為72秒,胚體之平均良率為97%。 Next, carry out the (wet) magnetic field alignment molding step, using a commercially available 25-ton semi-automatic wet magnetic field molding machine, to carry out magnetic field alignment molding of 20 green bodies on the modified ferrite magnetic powder, and the alignment magnetic field strength is 1.5 For Tesla, the forming pressure is 3.5 tons per square centimeter (Ton/cm 2 ), and the forming blank is a round blank with a size of Φ26.5 and a thickness of about 13mm. In Example 1, the average wet magnetic field forming time required for forming 20 green bodies was 72 seconds, and the average yield of green bodies was 97%.

最後,進行一燒結步驟,對該胚體以介於1220至1240℃之間的溫度持續燒結達60分鐘,以製得實施例1之該鐵氧體磁石。Finally, a sintering step is performed, and the green body is continuously sintered at a temperature between 1220° C. and 1240° C. for 60 minutes to obtain the ferrite magnet of Example 1.

比較例1至3Comparative Examples 1 to 3

比較例1至3大致上相同於實施例1,唯其不同之處在於細粉碎步驟不同,並且不具有混合步驟。具體地,比較例1至3的細粉碎步驟皆各自形成單級平均粒徑的細粉碎顆粒,例如比較例1是單級球磨得到平均粒徑約為0.95微米的細粉碎顆粒;比較例2是單級球磨得到平均粒徑約為0.55微米的細粉碎顆粒;以及比較例3是單級球磨得到平均粒徑約為0.75微米的細粉碎顆粒,如下表一所示。Comparative Examples 1 to 3 are substantially the same as Example 1 except that the fine pulverization step is different and there is no mixing step. Specifically, the fine pulverization steps of Comparative Examples 1 to 3 each form finely pulverized particles with a single-stage average particle diameter. Single-stage ball milling obtained finely pulverized particles with an average particle size of about 0.55 microns; and in Comparative Example 3, single-stage ball milled finely pulverized particles with an average particle size of about 0.75 microns, as shown in Table 1 below.

表一   球磨微粉碎方式 球磨微粉碎後之磁粉粒子徑 (μm) 球磨總時間 (小時) 磁石燒結密度 (g/cm 3) B r b H c i H c ( BH) max H k/ i H c 濕式磁場成型時間 濕式磁場成型良率 (G) (Oe) (Oe) (MGOe) (%) (秒) (%) 比較例1 單級球磨 0.95 3~4 4.83 4103 3721 4015 4.16 72.5 63 94 比較例2 單級球磨 0.55 9~10 4.91 4408 4329 4506 4.53 92.8 182 62 比較例3 單級球磨 0.75 7~8 4.96 4316 4287 4429 4.39 94.2 136 88 實施例1 分級混合級配球磨 0.75 9~10 5.08 4536 4352 4558 5.19 96.1 72 97 Table I Ball milling method Magnetic powder particle size after ball milling (μm) Total milling time (hours) Magnet Sintered Density (g/cm 3 ) B r b H c i H c ( BH ) max H k / i H c Wet magnetic field forming time Wet magnetic field forming yield (G) (Oe) (Oe) (MGOe) (%) (Second) (%) Comparative example 1 single stage ball mill 0.95 3~4 4.83 4103 3721 4015 4.16 72.5 63 94 Comparative example 2 single stage ball mill 0.55 9~10 4.91 4408 4329 4506 4.53 92.8 182 62 Comparative example 3 single stage ball mill 0.75 7~8 4.96 4316 4287 4429 4.39 94.2 136 88 Example 1 Grading mixed grading ball mill 0.75 9~10 5.08 4536 4352 4558 5.19 96.1 72 97

接著,利用市售儀器(中國計量科學研究院NIM-2000型 B-H Loop Tracer)量測各實施例與比較例中,各自的20顆鐵氧體磁石的各種磁氣性質,並且平均值計算,列於上表一。Then, utilize commercially available instruments (NIM-2000 type B-H Loop Tracer of China Institute of Metrology) to measure the various magnetic properties of 20 ferrite magnets in each embodiment and comparative example, and the average value is calculated, listed in Table 1 above.

依據日本TDK FB9B,其規格中值分別為:B r=4500G; bH c=4300Oe; iH c=4500Oe;(BH) max=4.9MGOe。若是低於上述的規格中值,則表示該鐵氧體磁石未達商用標準。因此,由上表二可知,比較例1至3並未達到日本TDK FB9B規格中值的要求,而實施例1達到日本TDK FB9B規格中值的要求。 According to Japan TDK FB9B, the median values of the specifications are: B r =4500G; b H c =4300Oe; i H c =4500Oe; (BH) max =4.9MGOe. If it is lower than the above-mentioned specification median value, it means that the ferrite magnet is not up to the commercial standard. Therefore, it can be seen from the above Table 2 that Comparative Examples 1 to 3 did not meet the requirements of the median value of the Japanese TDK FB9B specification, while Example 1 met the requirement of the median value of the Japanese TDK FB9B specification.

然而,比較例1至3的成型時間不僅高於實施例1之外,比較例1至3的成型良率也低於實施例1。就一般工業考量,成型時間需小於120秒,並且良率需達75%以上才屬合格製程。另外值得一提的是,由於粒徑大於0且小於等於0.05微米的細微顆粒係與成型時間有正相關,故可知實施例1中的細微顆粒的含量少於比較例1至3的細微顆粒的含量。However, the molding time of Comparative Examples 1 to 3 is not only higher than that of Example 1, but also the molding yield of Comparative Examples 1 to 3 is lower than that of Example 1. In terms of general industrial considerations, the molding time must be less than 120 seconds, and the yield rate must be over 75% to be a qualified process. It is also worth mentioning that since the fine particles with a particle size greater than 0 and less than or equal to 0.05 microns have a positive correlation with the molding time, it can be seen that the content of the fine particles in Example 1 is less than that of the fine particles in Comparative Examples 1 to 3. content.

實施例1可同時達到較高的整體磁特性以及較短的成型時間、較高的成型良率,其原因主要是: 因為實施例1中,取60±0.5%之「第一細粉碎顆粒」與40±0.5%之「第二細粉碎顆粒」,進行混合級配成實施例1之改質鐵氧體磁粉,其磁粉粒徑分佈窄且均勻(如第3圖所示)。微粉碎後的粒徑分佈若過大,容易於引起明顯的不連續晶粒成長,從而造成整體磁特性變差。反之,若粒度分佈愈窄,即瓷漿中磁粉的顆粒尺寸愈均勻,愈有利於後續濕式磁場成型與燒結。 由第3圖能明顯觀察到實施例1之磁粉粒徑分佈<0.1μm之超微細粉的比例明顯降低,可改善其成型性。另一方面,其整體磁粉粒徑峰值降至0.75±0.05μm,可提升其燒結後永磁鐵氧體磁石微觀組織中之單磁區晶粒比例,有助於提升其整體磁特性。以實施例1之分級混合級配球磨技術所得到之瓷漿,因最長球磨時間僅9~10小時,整體球磨時間短,有利於永磁鐵氧體磁石之大批量生產。Example 1 can simultaneously achieve higher overall magnetic properties, shorter molding time, and higher molding yield. The main reason is that in Example 1, 60±0.5% of the "first finely pulverized particles" are used Mix and grade with 40±0.5% of the "second finely ground particles" to form the modified ferrite magnetic powder of Example 1. The particle size distribution of the magnetic powder is narrow and uniform (as shown in Figure 3). If the particle size distribution after fine pulverization is too large, it is easy to cause obvious discontinuous grain growth, resulting in the deterioration of the overall magnetic properties. Conversely, if the particle size distribution is narrower, that is, the particle size of the magnetic powder in the porcelain slurry is more uniform, it is more conducive to the subsequent wet magnetic field forming and sintering. From Figure 3, it can be clearly observed that the proportion of ultrafine powder with a particle size distribution of <0.1 μm in the magnetic powder of Example 1 is significantly reduced, which can improve its formability. On the other hand, the peak particle size of the overall magnetic powder is reduced to 0.75±0.05μm, which can increase the proportion of single magnetic domain grains in the microstructure of the permanent ferrite magnet after sintering, and help to improve its overall magnetic properties. The porcelain slurry obtained by the graded mixing and grading ball milling technology in Example 1, because the longest ball milling time is only 9 to 10 hours, the overall ball milling time is short, which is beneficial to the mass production of permanent ferrite magnets.

另要需要詳細說明的是,比較例3之作法有別於實施例1,其中比較例3直接以「單級」球磨,以使瓷漿於微粉碎後平均磁粉粒度(D 50)達到0.75±0.05μm (利用費氏粒徑分析儀測量)之作法,其內部磁粉中所含<0.1μm之超微細粉的比例相對於實施例1仍然偏高(可從良率得知),因此比較例3相對於實施例1之作法對於提升瓷漿之成型性幫助甚低。 In addition, it needs to be explained in detail that the method of Comparative Example 3 is different from that of Example 1. In Comparative Example 3, the "single-stage" ball milling is used directly so that the average particle size (D 50 ) of the porcelain slurry after fine grinding reaches 0.75± In the method of 0.05 μm (measured by a Fischer particle size analyzer), the proportion of ultrafine powder <0.1 μm contained in the internal magnetic powder is still higher than that of Example 1 (it can be known from the yield rate), so Comparative Example 3 Compared with the practice of Example 1, the help for improving the moldability of the porcelain slurry is very low.

綜上所述,本發明實施例之改質鐵氧體磁石的製造方法可節省成型所需時間,並且良率大於75%(甚至達97%),並且對於永磁鐵氧體磁體的剩磁、矯頑磁力、矩形度以及磁場配向度也起到顯著提升的效果。In summary, the manufacturing method of the modified ferrite magnet according to the embodiment of the present invention can save the time required for molding, and the yield rate is greater than 75% (even up to 97%), and the residual magnetism of the permanent ferrite magnet, The coercive force, squareness and magnetic field alignment also play a significant role in improving.

雖然本發明已以較佳實施例揭露,然其並非用以限制本發明,任何熟習此項技藝之人士,在不脫離本發明之精神和範圍內,當可作各種更動與修飾,因此本發明之保護範圍當視後附之申請專利範圍所界定者為準。Although the present invention has been disclosed with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

10:方法 11~15:步驟 20:方法 21~23:步驟 10: method 11~15: Steps 20: method 21~23: Steps

第1圖是本發明一實施例之改質鐵氧體磁粉的製造方法之流程方塊圖。 第2圖是本發明一實施例之改質鐵氧體磁石的製造方法之流程方塊圖。 第3圖是實施例1、比較例1及比較例2的細粉碎顆粒的粒徑分布圖。 FIG. 1 is a flow block diagram of a manufacturing method of modified ferrite magnetic powder according to an embodiment of the present invention. FIG. 2 is a flow block diagram of a manufacturing method of a modified ferrite magnet according to an embodiment of the present invention. Fig. 3 is a particle size distribution diagram of finely pulverized particles of Example 1, Comparative Example 1, and Comparative Example 2.

10:方法 10: method

11~15:步驟 11~15: Steps

Claims (10)

一種改質鐵氧體磁粉的製造方法,其包含步驟: 提供一混合物,其中該混合物包含一氧化鐵粉及一鍶化物; 進行一煅燒步驟,對該混合物以1260至1300℃之間的溫度持溫達50至70分鐘之間,以形成一前處理物; 對該前處理物進行一粗粉碎步驟,以形成多個粗粉碎顆粒,其中以使該些粗粉碎顆粒的一平均粒徑介於2.5至2.7微米之間; 對該些粗粉碎顆粒進行一細粉碎步驟,其中該細粉碎步驟分別將該些粗粉碎顆粒粉碎成第一細粉碎顆粒及第二細粉碎顆粒,其中該第一細粉碎顆粒的一平均粒徑介於0.9至1微米之間,以及該第二細粉碎顆粒的一平均粒徑介於0.5至0.6微米之間;以及 混合該第一細粉碎顆粒以及該第二細粉碎顆粒以獲得該改質鐵氧體磁粉,其中該改質鐵氧體磁粉的一平均粒徑介於0.7至0.8微米之間。 A method for manufacturing modified ferrite magnetic powder, comprising the steps of: providing a mixture, wherein the mixture comprises iron oxide powder and a strontium compound; Carrying out a calcination step, keeping the mixture at a temperature between 1260°C and 1300°C for between 50 and 70 minutes to form a pretreatment; performing a coarse crushing step on the pre-treated material to form a plurality of coarse crushed particles, wherein an average particle diameter of the coarse crushed particles is between 2.5 and 2.7 microns; A fine crushing step is performed on the coarsely crushed particles, wherein the finely crushed step crushes the coarsely crushed particles into first finely crushed particles and second finely crushed particles, wherein an average particle diameter of the first finely crushed particles is between 0.9 and 1 micron, and an average particle size of the second finely divided particles is between 0.5 and 0.6 micron; and The first finely pulverized particles and the second finely pulverized particles are mixed to obtain the modified ferrite magnetic powder, wherein an average particle diameter of the modified ferrite magnetic powder is between 0.7 and 0.8 microns. 如請求項1所述之改質鐵氧體磁粉的製造方法,其中該前處理物的一分子式係SrO.nFe 2O 3,其中n介於5至6之間。 The manufacturing method of modified ferrite magnetic powder as described in Claim 1, wherein a molecular formula of the pretreatment substance is SrO. nFe 2 O 3 , where n is between 5 and 6. 如請求項1所述之改質鐵氧體磁粉的製造方法,其中該混合物更包含一鈷化物及一鑭化物中的至少一種。The manufacturing method of the modified ferrite magnetic powder according to claim 1, wherein the mixture further includes at least one of a cobalt compound and a lanthanum compound. 如請求項3所述之改質鐵氧體磁粉的製造方法,其中該前處理物的一分子式係(Sr 2+ 1-xLa 3+ x)O.n(Fe 3+ 1-yCo 2+ y) 2O 3,其中n介於5至6之間,x介於0.25至0.3之間,以及y介於0.01至0.02之間。 The manufacturing method of modified ferrite magnetic powder as described in Claim 3, wherein a molecular formula of the pretreatment is (Sr 2+ 1-x La 3+ x )O. n(Fe 3+ 1-y Co 2+ y ) 2 O 3 , wherein n is between 5 and 6, x is between 0.25 and 0.3, and y is between 0.01 and 0.02. 如請求項1所述之改質鐵氧體磁粉的製造方法,其中在提供該混合物的步驟中,更包含:提供一添加劑,其中該添加劑包含碳酸鈣、氧化矽、五氧化二磷以及氧化硼中的至少一種。The method for manufacturing modified ferrite magnetic powder as described in Claim 1, wherein in the step of providing the mixture, it further includes: providing an additive, wherein the additive includes calcium carbonate, silicon oxide, phosphorus pentoxide and boron oxide at least one of the 如請求項5所述之改質鐵氧體磁粉的製造方法,其中該添加劑包含碳酸鈣及氧化矽,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;以及氧化矽係介於0.2至0.8重量份之間。The manufacturing method of modified ferrite magnetic powder as described in Claim 5, wherein the additive comprises calcium carbonate and silicon oxide, and based on a total weight of the mixture being 100 parts by weight, calcium carbonate is between 0.5 and 1.5 parts by weight Between parts; and silicon oxide is between 0.2 to 0.8 parts by weight. 如請求項5所述之改質鐵氧體磁粉的製造方法,其中該添加劑包含碳酸鈣、氧化矽、五氧化二磷以及氧化硼,並且以該混合物的一總重為100重量份計,碳酸鈣係介於0.5至1.5重量份之間;氧化矽係介於0.2至0.8重量份之間;五氧化二磷係大於零且小於等於0.1重量份;以及氧化硼係大於零且小於等於1重量份。The manufacturing method of modified ferrite magnetic powder as described in claim 5, wherein the additive comprises calcium carbonate, silicon oxide, phosphorus pentoxide and boron oxide, and based on a total weight of the mixture being 100 parts by weight, carbonic acid Calcium is between 0.5 and 1.5 parts by weight; silicon oxide is between 0.2 and 0.8 parts by weight; phosphorus pentoxide is greater than zero and less than or equal to 0.1 parts by weight; and boron oxide is greater than zero and less than or equal to 1 weight share. 如請求項1所述之改質鐵氧體磁粉的製造方法,其中在提供該混合物的步驟之後以及進行該煅燒步驟之前更包含對該混合物進行一脫水步驟,其中經該脫水步驟處理後的該混合物的含水率係介於18%至24%之間。The method for manufacturing modified ferrite magnetic powder as described in Claim 1, wherein after the step of providing the mixture and before the step of calcination, it further includes a dehydration step of the mixture, wherein the dehydration step treats the The moisture content of the mixture is between 18% and 24%. 如請求項1所述之改質鐵氧體磁粉的製造方法,其中以該改質鐵氧體磁粉的總重為100wt%,該第一細粉碎顆粉係介於59.5wt%至60.5wt%之間,以及該第二細粉碎顆粒係介於39.5wt%至40.5wt%之間。The manufacturing method of modified ferrite magnetic powder as described in Claim 1, wherein the total weight of the modified ferrite magnetic powder is 100wt%, and the first finely pulverized powder is between 59.5wt% and 60.5wt% Between, and the second finely divided particles are between 39.5wt% and 40.5wt%. 一種改質鐵氧體磁石的製造方法,其包含步驟: 提供一改質鐵氧體磁粉,其中該改質鐵氧體磁粉係通過如請求項1至9任一項所述之改質鐵氧體磁粉的製造方法所製成; 對該改質鐵氧體磁粉進行一磁場配向成型步驟,以形成一胚體,其中該磁場配向成型步驟的一配向磁場強度係介於1.3至1.7特斯拉之間,一成型壓力係介於3至4噸/平方公分之間,以及一成型時間係介於90至110秒之間;以及 進行一燒結步驟,對該胚體以介於1220至1240℃之間的溫度持續燒結達50至70分鐘之間,以製得一鐵氧體磁石。 A method for manufacturing a modified ferrite magnet, comprising the steps of: A modified ferrite magnetic powder is provided, wherein the modified ferrite magnetic powder is made by the method for manufacturing modified ferrite magnetic powder as described in any one of Claims 1 to 9; A magnetic field alignment molding step is performed on the modified ferrite magnetic powder to form a green body, wherein an alignment magnetic field strength of the magnetic field alignment molding step is between 1.3 and 1.7 Tesla, and a molding pressure is between Between 3 and 4 t/cm2, and a molding time between 90 and 110 seconds; and A sintering step is performed, and the green body is continuously sintered at a temperature between 1220-1240° C. for 50-70 minutes to obtain a ferrite magnet.
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