JPS6092404A - Production of powder sintered product - Google Patents

Abstract

PURPOSE:To produce a powder sintered product with high production efficiency by compressing raw material powder to prescribed density by a wet press method and cutting equally the resulting molding to a desired height in the direction orthogonal to the compressing direction then sintering the molding. CONSTITUTION:Raw material powder such as ferrite or the like is loaded into the space part 8 formed of a lower punch 2 constituting a male die fixed onto the base plate 1 of a wet press device and a femal die 4 and an upper punch 5 mounted with a filter 9 to an upper plate 3 is lowered by a hydraulic cylinder 6 to press and dehydrate the powder by which a powder molding is obtd. The raw material powder is compressed 50-65% of the theoretical density at the height above the molding height adding an allowance for cutting to at least two- fold the height of the molding equivalent to the required height of the sintered product and below 50mm.. The molding obtd. in such a way is equally cut to the height equivalent to the required height of the sintered product in the direction orthogonal with the compressing direction and is then sintered.

Description

[Detailed description of the invention]

This invention relates to a method for producing powder sintered crystals obtained by wet-pressing and sintering raw material powders of fluorites, and relates to a production method that significantly improves the production efficiency of powder compacts. In general, no

[When forming blended raw material powder such as sheets into a ring-shaped or flat plate-shaped body using a wet press,
It takes a lot of time to dehydrate, pass through, etc. during molding, so in order to improve press efficiency, it is necessary to widen the molding space and configure multiple molds. Moreover, it required a pressing force of 100 tons or more. However, when molding a disk-shaped molded object with a diameter of, for example, 100 mm using a 200 ton press, only 5 pieces can be formed in one molding at most, which is different from the case with a highly productive mechanical press. In comparison, there was a problem of poor manufacturing efficiency and high costs. The invention aims to improve the low production efficiency of the conventional wet press method when obtaining molded bodies from raw materials such as ferrite 1 and ceramic powder. The purpose of the present invention is to provide a method for producing powder sintered crystals that dramatically improves the production efficiency per batch and achieves low cis i. That is, the present invention uses a wet pressing method to form raw material powder into a material having a theoretical density at a height that is at least twice the height of the compact corresponding to the required sintered product height plus a cutting allowance and at most 5'Om+n. Production of a powder sintered crystal characterized by compressing to 50% to 65%, cutting the obtained molded body into equal parts in a direction perpendicular to the compression direction to a height equivalent to the required sintered product height, and then sintering. It's a method. This invention can be applied to powder molding of various materials such as hard ferrite, light, and soft ferrite, as well as metals and Reramix, and can significantly improve manufacturing efficiency per wet press and reduce costs. In addition, various cutting methods such as cutting with a grindstone such as diamond or G-C, cutting with a blade saw, cutting with a hand saw, cutting with a high-pressure water jet, laser cut, etc. can be used to cut the molded product according to the present invention. can. Next, the compact of the present invention was compressed to 50% of the theoretical density.
The reason for limiting the range to 65% is that if it is less than 50% of the theoretical density, the required magnetic properties cannot be obtained in the case of llt&bamboo materials after firing, and handling after molding becomes difficult.
]%, a very large R1 force is required to compress the raw powder, which may cause problems with the strength of dies and punches.
This is because the apparent density becomes saturated, which is undesirable. In addition, the height of the compression molded body was set to 50 mm or less.
This is because if it exceeds 0 mm, it is difficult to completely dehydrate the raw material powder and it is impossible to press it into a good product. This invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of the wet press apparatus. In the press device, a lower punch (2) constituting a male die is fixed on a base (1), and an upper punch (5) consisting of a female die (4) hanging from an upper plate (3) is moved upward and downward. It is configured to be movable up and down by a pair of hydraulic cylinders (61 (7)) placed in the lower punch (2) and the upper punch (5
) is fitted onto the outside of the space (8) formed by the blended raw material powder, and the upper part of the raw II powder and the upper plate (part 31) are fitted with a filter (9) for smooth dehydration of the powder. Here, when loading the space (8) and compression molding, the height of the molded body is set to 218 or more, which corresponds to the required height of the sintered product, plus the cutting allowance. The compact is compressed at 50% to 65% of the theoretical density so that the height is 50 mm or less. In other words, if the height of the compact is four times the height of the sintered product, cut it into four equal parts, and then sinter the cut compact to make the required product. , with a press machine with the same capacity, the number of molded bodies with the required height obtained in one press is at least twice that of the conventional method, and furthermore, the required height is more than the time required for one press. 1. Turn the compact into a plurality of sintered products.
Since the IJ cutting time is shorter, the production per hour is lower.
1 has increased significantly [1, production efficiency has greatly improved. Examples are shown below. Here, a case will be described in which a donut-shaped product having a sintered product composition of SrO.6Fe203 and dimensions of 60 mu + x inner diameter and 611 m x + x 611 m x + dimensions will be described. The raw material powder blended so that the composition after sintering would have the above composition was loaded into a 200 ton wet press machine having the configuration shown in Fig. 1, and pressed at a pressure of 0.5 t4 to form an outer diameter of 60 mm x an inner diameter of 2 mm.
0mm x aza 20mm'CI method, apparent density is 3.3
A4 (60% of theoretical density) compact was compression molded. 1
15 pieces were molded in one molding process, and the time required for the molding process was 10
It was seconds. The molded body was cut using a high-pressure water jet cutting device 19i at a pressure of 6001q4. It was divided into three equal heights under the conditions of cutting widths of 0 and 2 mm to obtain a molded body 6 mm in height. Thereafter, the cut compact was treated with a skin binder and sintered. The number of sintered products obtained by one pressing and cutting process according to the method of this invention was 45, and the time required for pressing and cutting was 100 seconds. In addition, for comparison, 45 sintered products were obtained using the conventional method using the same press equipment.
The time required for pressing was 210 seconds, and it is clear that the production efficiency of the method of the present invention is more than twice that of the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the wet press apparatus. DESCRIPTION OF SYMBOLS 1...Base, 2...Lower punch, 3...Upper plate, 4...Die die, 5...Upper punch, 6, 7...
...Hydraulic cylinder, 8...Space, 9...Filter. Applicant: Sumitomo Special Metals Co., Ltd.

Claims (1)

[Claims] 1 1J stone powder is processed by the wet Soles method to a molding height that is at least twice the height of the molded product equivalent to the required sintered product height, taking into account the cutting allowance, and a height of 50mm or more, and 50% of the theoretical density. The molded body obtained was compressed to ~65% and cut into equal parts at a height corresponding to the height of the product required to be sintered in the same direction as I'I in the direction of compression.
Production of powder sintered crystal characterized by post-sintering
Δ method.