JPH04198405A - Production of hard long raw material with hole - Google Patents

Abstract

PURPOSE:To efficiently obtain the raw material having excellent internal quality by penetrating core member, which can decompose during debinder treatment, to hard powder raw material containing binder sealed in a compacting die composed of a cylinder sealing both opening parts and embedding it. CONSTITUTION:One end side of a core member 3 is fixed to a sealed cover 2 and the other side of this core member 3 is freely inserted from the one end side of rubber cylinder 1 and also the sealed cover 2 is fitted to the opening part at one end side of the cylinder 1. Successively, the powder P is packed from the opening part at the other end side of cylinder 1 and free end side of the core member 3 is penetrated to the other cover 2, and the cover 2 is fitted to the opening part at the other end side of cylinder 1 and also the core member 5 is fixed to obtain a compacting mold (m) sealing the powder P. Further, isostatic pressure is acted to the compacting mold (m) to obtain the long green compact 4 embedding the core member 3 and this is separated from the mold and the debinder treatment is executed at the temp., which can decompose the core member 3, and this is sintered to obtain the raw material. Further, by twisting the green compact 4, the long twisted body embedding the core member 3 as spiral state is obtd.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a hard elongated material with holes, which manufactures a hard elongated material with holes from a hard powder raw material made of cemented carbide, cermet, ceramics, or the like. [Conventional technology]

As is well known, hard materials include metals, metal carbides,
The raw material is powder made of hard materials such as nitrides, oxides, and ferrides, and hard material products are made from these hard powder raw materials (
It is manufactured by kneading and bonding one or more types of binder to a powder source 1'-1 (hereinafter referred to as powder source 1'-1) and then molding, and after molding, performing various treatments such as binder removal treatment, machining, and sintering. By the way, as methods for forming the molding material, for example, the molding method, injection molding method, doctor blade method, etc. are known, and the manufacturing of tools such as drills and end mills requires long molding materials. , extrusion molding methods are widely used. 1. The extrusion molding method involves kneading one or more types of binder with a powder raw material to create a plastic kneaded body (hereinafter referred to as a kneaded body), and extruding this by an extrusion molding machine through an extrusion die having a predetermined 1jji surface shape. It is manufactured by molding elongated elements 1A having various cross-sectional shapes. However, in order to improve the plasticity of the kneaded material in order to cope with the increase in extrusion resistance due to the complicated cross-sectional shape of the extruded material, for example, Japanese Patent Publication No. 59-26653,
Special Publication No. 62-59074, Special Publication No. 61-4602
As seen in Japanese Patent Publication No. 6, Japanese Patent Publication No. 1-24743, etc., it has become unavoidable to mix more and more common types of binders into powder raw materials. That is, as the structure of the extrusion die becomes more complex, the extrusion resistance of the kneaded body increases, so this is dealt with by increasing the amount and type of binder to improve the plasticity of the kneaded body.

[Invention or problem to be solved]

As mentioned above, it is true that the kneaded product can be easily extruded from an extrusion die by improving the plasticity of the kneaded product, or other problems as described below occur due to an increase in the amount of binder. First, the first problem is that a large amount of binder flows out at once during the binder removal process, which increases the frequency of cracks in the molding material and increases the defective rate of the product. This can be avoided by slowing down the temperature increase rate when performing the binder removal process, but this is not preferable since the production efficiency decreases as the process time increases. In addition, the second problem is that bores tend to remain in the structure of the sintered product after sintering, and this has a negative impact on product quality, such as damage. For example, in the case of cemented carbide, not only does a defective structure such as free carbon occur in the sintered structure, but also the amount of shrinkage and bending deformation after sintering increases. This results in a decrease in quality, an increase in machining costs, and a decrease in yield due to insufficient dimensions. Therefore, the present invention can efficiently produce a hard long material with holes with excellent internal quality. The purpose of this invention is to provide a method for manufacturing a hard long material with holes.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems. Therefore, the gist of the method for manufacturing a hard elongated material with holes according to the first invention is as follows: In a mold consisting of a sealing lid that seals both openings, a hard powder raw material is sealed together with a predetermined amount of binder, and a core member made of an organic substance supported by the sealing lid is buried in the hard powder raw material. The method is characterized in that a molded body obtained by applying hydrostatic pressure to a mold is demolded, subjected to a binder removal treatment at a temperature at which the core member can be decomposed, and then subjected to a predetermined sintering treatment. Further, the gist of the method for producing a hard elongated material with holes according to the second invention is to place a predetermined amount of hard powder raw material into a mold consisting of a cylinder and a sealing lid that seals both openings of the cylinder. A core member made of an organic substance sealed together with a binder and supported by the sealing lid is embedded in a hard powder raw material, and hydrostatic pressure is applied to the mold to demold the resulting molded body and heat it to a predetermined temperature. It is characterized in that the core member is twisted while being heated, and then the binder is removed at a temperature at which the core member can be decomposed, and then a predetermined sintering process is performed. [Function] According to the method for manufacturing a hard elongated material with holes according to the first invention,
By the pressurizing action of hydrostatic pressure, a molded body with a core member embedded inside is obtained from the powder raw material and a small amount of binder, which are sealed in a cylinder with a sealing lid, and this molded body is separated from the core member. During the binder removal process, the core member is removed and a through hole is left in the molded body, and by sintering this, a hard elongated material with holes is obtained. It will be done. According to the method for manufacturing a hard elongated material with holes according to the second aspect of the invention, a powder raw material sealed with a sealing lid and a small amount of binder are mixed into a core member inside the cylindrical body by the pressurizing action of hydrostatic pressure. A molded body in which is embedded is obtained, and this molded body can be easily twisted due to improved plasticity by heating at a predetermined temperature. Next, the core member is de-pindered at a temperature that can decompose it, so during the de-bindering process, this core part A is removed, leaving a through hole in the molded body, and the hole twisted by the sintering process is removed. It is possible to obtain a rigid long material with a tack. [Example] Examples according to the present invention are shown in FIG. 1, which is a side sectional view of a mold, FIG. 2, which is a perspective view of the obtained elongated molded body, and by twisting]
While referring to FIG. 3, which is a perspective view of the twisted elongated molded body, FIG. 4, which is a schematic side view of the twisting device, and FIG. This will be explained below. That is, the symbol m shown in FIG. 1 is a mold, and this mold m consists of a comb tube 1 and a sealing lid 2 made of rubber that is fitted into both openings of the comb tube 1. Two cores (A3) made of nylon strings are supported by these sealing lids 2 at a predetermined distance and in parallel. Inside this mold m is a WC-CO based core. 1.5wt% paraffin wax and 0.5W as a paraffin binder are applied to the surface of the powder raw material that will become the cemented carbide.
P powder coated with t% ethylene vinyl acetate
Or one Jr. will be taken. Note that a kneaded body consisting of a powder raw material and a predetermined amount of binder may be used. The powder p is encapsulated by the following procedure. That is, the procedure for sealing the powder P is to first fix one end of the core member 13 to the sealing lid 2, loosely fit the other end of the core member 3 from one end of the comb cylinder 1, and then A sealing lid 2 is fitted into the opening at one end of the cylinder 1. Next, fill the powder p from the opening on the other end side of the rubber cylinder l,
By passing the free end of the core shell 3 through another sealing lid 2, fitting this sealing lid 2 into the opening on the other end of the rubber cylinder 1, and fixing the core member 3, the powder p can be removed. A mold m in which the mold is enclosed is obtained. Next, for the mold m obtained in this way, 1000
A hydrostatic pressure of kgf/crtl is applied to obtain a long molded body 4 in which the core member 3 is embedded, and this is twisted by a torsion device IO having a configuration described later, as shown in FIG. A long twisted body 5 in which the core member 3 was embedded in a spiral shape was manufactured. In this case, the long molded body 4 is formed by isostatic pressing.
The mold M was pressed to 1500kgf/
cn? It has been confirmed that an equivalent long molded body 4 can also be formed by applying pressure. Hereinafter, the details of the above-mentioned sheet-shaping device 10 will be explained based on FIG. 4 and FIG. 5, which are explanatory diagrams of its configuration. , a frame body 1 having a passage hole 1 through which the elongated molded body 4 passes, approximately in the center thereof;
1 is installed. The passage hole 11 is formed on one side of the frame 11.
Three rotary rollers 12 are rotatably supported at the same distance and at equal intervals to be in contact with the outer circumferential portion of the long molded body 4, and all of these three rotary rollers 12 are connected to the frame Il. A pulse motor 13 attached to the other side of the
It is designed to be rotated by Further, an annular heater 14 is disposed at a position opposite to the support side of the rotating roller I2 and close to the rotating roller 12 so as to be concentric with the center of the passage hole 11a. Furthermore, a track 15 is provided on the opposite side of the rotating roller 12 of the workbench S.
A long molded body 4 is laid by this track 15.
A chuck device 16 that grips one end side is supported so as to be able to approach and retreat from the frame 11. On the other hand, on the other side of the frame 11 and on the workbench S, a long torsion body 5 is held rotatably around two rotation axes parallel to the rotation axis of the rotation roller 12. The structure includes a holding table 17 that supports a holding roller row 17a. Hereinafter, to explain how to use the twisting device 10 having the configuration described in item 1, first, one end of the elongated molded body 4 is
while holding this chuck device 16 with the frame 11.
move towards. Then, the long molded body 4 is heated to 60 to 70°C through the annular heater I4,
Its plasticity is reversed and it continues to be fed in sequence between three rotating rollers 12 that are rotated by a pulse motor 13. On the other hand, since the rotating roller 12 is rotated at a predetermined accurate rotation speed by the pulse motor 13, this rotating roller 1
2, the long molded body 4 passes through the passage hole 11a of the frame body 11 while being twisted, and the part beyond passing through the passage hole 11a is rotated according to the rotation speed of the pulse motor 13 by the holding roller row 17a. By being guided and twisted, a long plate body 5 in which the core member 3 is embedded in a spiral shape as shown in FIG. 3 is obtained. Then, the twisted long plate body 5 was subjected to binder removal treatment at a temperature of 450° C. in a hydrogen atmosphere. Then, during this binder removal process, the core portion u3 is decomposed and removed by reaction with hydrogen, leaving a spiral hole in the buried portion of the core member 3. Next, this is pre-sintered at a temperature of 840°C, further vacuum-sintered at a temperature of 1400'C, and ground with a diamond grindstone to obtain a diameter of 1 in a well-known configuration.
A 5mm drill was manufactured. By the way, when extruding a molded body with through holes using a conventional molding method, it is necessary to knead at least 8 wt % of binder with respect to the WC-Co powder raw material. In this example, since molding can be performed with a small amount of binder as described above, various problems that have conventionally occurred, such as cracks in the molded material, residual defects in the structure of the sintered product, and free carbon in the sintered structure, can be avoided. This makes it possible to avoid the occurrence of defective structures, shrinkage after sintering, bending deformation, insufficient dimensions, etc. As can be well understood from the above explanation, according to the manufacturing method of the hard elongated moon with holes according to this embodiment, the twisting pitch can be freely changed by controlling the rotation speed of the pulse motor 13. Drills and end mills disclosed in JP-A No. 60-206523 and JP-A No. 61-219536, etc., in other words, the lead angle increases as it approaches the tip, reducing cutting vibration and increasing oil discharge amount. It can be extremely effective in manufacturing drills and end mills that can be expected to have the following properties. In the above, the production of a hard elongated material with a hole having a spiral hole has been explained, or rather, the elongated molded body 4 is not subjected to twisting processing, but is subjected to a predetermined sintering treatment after removing the binder. For example, a hard elongated material with a hole for a gun drill having a straight oil chamber at an eccentric position on one side of the center line passing through the radial center of the elongated molded body 4 (not shown)
It is also possible to manufacture the core member 3, and the position of embedding the core member 3 in the powder p can be freely determined. [Effects of the Invention] As described in detail below, according to the method for manufacturing a hard elongated material with holes according to the first invention and the second invention, the holes are tightly formed in the cylinder by the action of hydrostatic pressure. A molded body with a core member embedded inside is obtained from the sealed powder raw material and a small amount of binder, and the molded body is subjected to binder removal treatment at a temperature that allows the core member to decompose. The core member inside is removed and a through hole is left in the molded body, and by sintering this, a hard elongated material with holes is obtained, and furthermore, a hard elongated material with holes is obtained according to the second invention. According to this manufacturing method, a hard long blank with a spiral hole can be easily obtained, so there are no cracks in the forming material, which is an interlayer in the conventional forming method, and defects in the structure of the sintered product. This prevents the occurrence of defective structures due to the residual amount of decomposition residue after binder removal, deterioration of quality due to shrinkage and bending deformation after sintering, increase in machining costs, and decrease in yield due to insufficient dimensions. This can be expected to have an extremely large effect on productivity improvement and quality improvement.

[Brief explanation of the drawing]

1 to 5 relate to examples of the present invention, in which FIG. 1 is a side sectional view of the mold, FIG. 2 is a perspective view of the obtained long molded product, and FIG. 3 is a twisting process. FIG. 4 is a side view of the twisting device, and FIG. 5 is a sectional view taken along line A--A in FIG. 4. 1... Rubber tube, 2... Sealing lid, 3... Core member, 4
...Long molded body, 5...Long plate jiggly body, 10...
Twisting device, 11... Frame, lla... Passing hole, 1
2... Rotating roller, 13... Pulse motor, 14...
... Annular heater, 15... Orbit, 16... Chuck device, 17... Holding stand, +7a... Holding roller row, m... Molding mold, p... Powder, S... ·Workbench. Patent Applicant Kobe Steel Corporation Representative Patent Attorney Akira Kanemaru −

Claims (1)

[Scope of Claims] 1. A hard powder raw material is sealed together with a predetermined amount of binder in a mold consisting of a cylinder and a sealing lid that seals both openings of the cylinder, and an organic substance is supported by the sealing lid. A core member consisting of is embedded in a hard powder raw material, hydrostatic pressure is applied to the mold, the resulting molded body is demolded, and the core member is subjected to debinding treatment at a temperature at which it can be decomposed, and then a predetermined amount of A method for manufacturing a hard elongated material with holes, characterized by subjecting it to a sintering process. 2. A hard powder raw material is sealed together with a predetermined amount of binder in a mold consisting of a cylindrical body and a sealing lid that seals both openings of the cylindrical body, and a core member made of an organic substance supported by the sealing lid is hardened. The core member is embedded in a powder raw material, and the molded body obtained by applying hydrostatic pressure to the mold is demolded and twisted while being heated to a predetermined temperature, and then the core member can be decomposed. A method for manufacturing a hard elongated material with holes, the method comprising performing a predetermined sintering treatment after debinding at a high temperature.