摘要:
PROBLEM TO BE SOLVED: To provide a method for production of a W-type ferrite improved in magnetic characteristic, particularly in coercive force. SOLUTION: This method for producing the ferrite magnetic material having a hexagonal W-type ferrite as a main phase comprises a forming process for making a formed body containing a main ingredient and the first accessory ingredient comprising one, two or more selected from the ingredients of Ga, Al, W, Ce, Mo and Cr and a firing process for firing the resultant formed body. The formed body may comprise a calcined body containing both the main and the first accessory ingredients or may comprise a mixture of a calcined body composing the main ingredient with the first accessory ingredient. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a technique for improving a sintering density with gaining an effect of carbon addition. SOLUTION: The method for manufacturing an oxide sintered compact comprises a forming process of forming a mixture containing a raw material powder, a carbon powder and a polycarboxylic acid-based dispersant and a sintering process of sintering a formed body obtained and of giving a sintered compact. The polycarboxylic acid-based dispersant suppresses the segregation of the carbon powder, so that the increase in pinholes and the decrease in the sintering density caused thereby may be suppressed even if the carbon powder vanishes at the time of sintering. Consequently, the segregation of the carbon powder can be suppressed and a high density, oxide sintered compact can be obtained with gaining an effect of the carbon addition. Being applied to a W-type ferrite magnet, the W-type ferrite magnet with a high remanent magnetic flux density (Br) can be obtained. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a technology effective for an improvement in the residual magnetic flux density (Br) and the coercive force (HcJ) of an La-Co containing M-type ferrite sintered magnet without increasing the content of Co. SOLUTION: There is provided a ferrite magnetic material comprising a ferrite having a hexagonal structure as a main phase, which contains A, La, R, Fe and Co. A is at least one element selected from among Sr, Ba and Pb, and R is Pr and/or Nd. The component ratios of the total of the respective metallic elements A, La, R, Fe and Co in the main phase to the total amount of the metallic elements are A:1 to 13 atomic%, La:0.003 to 10 atomic%, R:0 to 10 atomic % (excluding 0), Fe:80 to 95 atomic%, and Co:0.05 to 5 atomic%. By including one or two kinds of Pr and Nd together with La and Co, the residual magnetic flux density (Br) and the coercive force (HcJ) can be improved without increasing the content of Co. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To improve magnetic characteristics of a W-type ferrite, especially its coercive force. SOLUTION: The manufacturing method of a ferrite magnetic material has a process (a) for calcining the mixture wherein the Ca component of not smaller than 0.01 wt.%, and smaller than 1.0 wt.% obtained when calculating it in terms of CaCO 3 is added to the raw-material powder containing an A component (where A represents one or more kinds of elements selected from Sr, Ba, and Pb) and an Fe component; a process (b) for crushing the calcined material obtained in the process (a); a process (c) for molding in a magnetic field the crushed powder obtained in the process (b); and a process (d) for so baking the molded body obtained in the process (c) as to obtain the sintered body whose magnetic phase is a hexagonal crystal W-type ferrite. Since the crystal grains of the sintered body are made fine by adding the Ca component of the predetermined quantity to the raw-material powder when blending the raw-material powder, the coercive force (HcJ) of the ferrite magnetic material which exceeds 30,000e can be obtained. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a W type ferrite sintered compact which has high existence ratio of a W phase in the entire area of the sintered compact and to provide its production process. SOLUTION: The W type ferrite sintered compact having ≥65% existence ratio of the W phase within the sintered compact and ≤20%/mm change rate of the existence ratio of the W phase is obtained by making a raw material composition containing ≥0.05 to COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a ferrite magnetic material comprising a main phase of W-type, which has magnetic properties improved through the optimization of additives. SOLUTION: The ferrite magnetic material comprises, as a main phase, a hexagonal W-type ferrite and a Ga-constituent in an amount of 15 wt.% or less (not including zero) expressed in terms of Ga 2 O 3 . The ferrite magnetic material comprises, as a main constituent, a compound represented by composition formula: AFe 2+ a Fe 3+ b O 27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.5≤a≤2.1; and 12.9≤b≤16.3). Alternatively, the ferrite magnetic material comprises, as a main constituent, a compound represented by composition formula: AZn c Fe d O 27 (wherein A comprises at least one element selected from Sr, Ba and Pb; 1.1≤c≤2.1; and 13≤d≤17). COPYRIGHT: (C)2010,JPO&INPIT
摘要翻译:要解决的问题:提供一种包括W型主相的铁氧体磁性材料,其通过优化添加剂而具有改进的磁性能。 解决方案:铁氧体磁性材料包括以Ga 表示的15重量%以下(不包括零)的量的六方晶型W型铁素体和Ga成分作为主相, 2 SB> O 3 SB>。 铁氧体磁性材料以组成式表示的化合物作为主要成分包含:AFe 2 + SP> a SB> Fe 3 + (其中A包含选自Sr,Ba和Pb中的至少一种元素;1.5≤a≤2.1;和12.9≤b≤16.3)。 或者,铁氧体磁性材料以组成式表示的化合物作为主要成分包含:其中A 包括选自Sr,Ba和Pb中的至少一种元素;1.1≤c≤2.1;和13≤d≤17)。 版权所有(C)2010,JPO&INPIT
摘要:
PROBLEM TO BE SOLVED: To provide a method of obtaining a W-type ferrite sintered compact high in the existing ratio of W phase in the whole range of the sintered compact. SOLUTION: This manufacturing method comprises a molding process in a magnetic field in which a feed composition containing a specified quantity of a reducing agent is molded to form a molding, and a firing process in which the molding is fired by raising the temperature of the molding in the reducing temperature range of the reducing agent at a speed of not greater than 4°C/min (excluding 0). It is preferable that the firing is carried out after a heat treatment in which the molding is kept at a temperature of 200-400°C in an oxidizing atmosphere. The sintered compact obtained by the method is rich in W phase in the sintered compact with its existing ratio of not lower than 90%. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a technique for improving a sintering density with gaining an effect of carbon addition. SOLUTION: The method for manufacturing an oxide sintered compact comprises a forming process of forming a mixture containing a raw material powder, a carbon powder and a polyoxyethylene-based dispersant and a sintering process of sintering a formed body obtained and of giving a sintered compact. The polyoxyethylene-based dispersant suppresses the segregation of the carbon powder, so that the increase in pinholes and the decrease in the sintering density caused thereby may be suppressed even if the carbon powder vanishes at the time of sintering. Consequently, the segregation of the carbon powder can be suppressed and a high density, oxide sintered compact can be obtained with gaining an effect of the carbon addition. Being applied to a W-type ferrite magnet, the W-type ferrite magnet with a high remanent magnetic flux density (Br) can be obtained. COPYRIGHT: (C)2006,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a technique for improving sintering density while fully receiving the effect of carbon addition. SOLUTION: The method is provided with: a molding process of molding a mixture containing raw material powder, carbon powder and a polyhydric alcohol expressed by the general formula: C x (OH) y H z (wherein 4≤x≤100, 2≤y≤x, 4≤z≤2x); and a sintering process of obtaining a sintered compact by sintering the resulting molding. The polyhydric alcohol suppresses the segregation of the carbon powder and therefore, even if the carbon powder disappears during the sintering, an increase of pinholes and the decrease in the sintering density due to the same can be suppressed. According to the method, the segregation of the carbon powder can be suppressed and the sintered oxide compact of high density can be obtained while the effect by the carbon addition is fully received. A W type ferrite magnet of a high residual magnetic flux density (Br) can be obtained by applying the method to the W type ferrite magnet. COPYRIGHT: (C)2005,JPO&NCIPI
摘要:
PROBLEM TO BE SOLVED: To provide a technology for improving sintered density while benefiting from carbon addition. SOLUTION: The manufacturing method of an oxide sintered compact comprises a molding step wherein a mixture containing a raw material powder, a carbon powder and a dispersant is molded and a sintering step wherein the obtained molded product is sintered to obtain the sintered compact. The dispersant used here is an organic compound having a hydroxy or carboxy group, its neutralized salt or its lactone, an organic compound having a hydroxymethylcarbonyl group or an organic compound having an enolic hydroxy group which can dissociate as an acid or its neutralized salt, wherein the organic compound has 3-20 carbons and has hydroxy groups bound to ≥50% of carbon atoms that are not forming double bonds with oxygen atoms. The dispersant (e.g. gluconic acid) inhibits segregation of the carbon powder and therefore inhibits increase in pinholes and the resulting decrease in sintered density, even when the carbon powder disappears at sintering. COPYRIGHT: (C)2005,JPO&NCIPI