JP6778509B2 - Wire saw device and method of cutting out powder molded product using this device - Google Patents

Description

The present invention uses a wire saw device, which is useful for producing a sintered body such as a predetermined cemented carbide by cutting out a secondary molded body having a predetermined shape from a powder molded body as a primary molded body. A method of cutting out a secondary molded product having a predetermined shape (or a cutting method) from a powder molded product (or compression molded product), and a method of sintering a secondary molded product to produce a sintered body (cemented carbide, etc.). Regarding.

Cemented carbide is widely used in cutting tools, excavators, punching metal fittings, and the like. Such a cemented carbide is usually prepared by a powder metallurgy method, for example, a powder mixture of tungsten carbide WC and cobalt is compression-molded into blocks, and if necessary, heat-treated (pre-sintered) to prepare a molded body. The sintered body is processed into a predetermined shape by using a diamond grindstone, a cutter, or the like in order to shape the shaped body into the shape of the above, sinter the shaped molded body, and further improve the dimensional accuracy. However, since cemented carbide has extremely high hardness, it is inferior in processability and greatly reduces the productivity of the product. In particular, when a plurality of products are cut out from a block-shaped sintered body, the productivity of the products is significantly reduced. In addition, the sintered body may be damaged during the processing process, which may reduce the yield of the product. Furthermore, the chips generated by the processing of the sintered body are sintered, so that it is difficult to reuse them.

Electric discharge machining (wire-cut electric discharge machining) is known as one of the processing methods for such a sintered body. However, in this electric discharge machining, since the electric discharge between the pair of electrodes is used to melt and cut, not only the energy consumption and the consumption of the electrodes are large, but also it is necessary to perform the electric discharge machining using an aqueous or oil-based machining liquid. is there.

On the other hand, it is conceivable to cut out a predetermined secondary molded body from the block-shaped primary molded body produced by compression molding of the powder mixture using a cutting tool, shape the molded body, and sinter the molded body. However, in this method, since the block-shaped primary molded body is chalk-shaped and soft and brittle, cracks are likely to be generated in the secondary molded body during cutting and shaping, and when the secondary molded body falls with the cutting. , The secondary molded body is damaged. Further, since the cutting portion is likely to be chipped at the end portion, it is necessary to cut the cutting allowance after performing a predetermined process by setting the end portion as a cutting allowance in consideration of the chipped portion. Therefore, as the number of steps increases, the yield decreases. Further, the fact that the primary molded body is easily damaged is a great adverse effect in efficient processing in a short time, and it is difficult to increase the productivity.

According to Japanese Patent Application Laid-Open No. 2003-165847 (Patent Document 1), a wire saw provided with a fine-grained hard cutting material on the surface is linearly fed by the opposing first and second guide mechanisms, and the first and second are described. A ceramic processing apparatus for processing the shape of the workpiece while pressing the wire saw against the ceramic workpiece fixed to a table arranged between the second guide mechanisms is described. In this apparatus, the table is used. , X and Y directions are described as XY tables that move freely or according to pre-programmed instructions. It is also described that the first and second guide mechanisms are controlled independently. However, in this device, when the ceramic is cut while feeding the wire saw, the ceramic is hard, so that the cut portion generates heat, and when the ceramic is cut by a dry method, the cutting efficiency by the wire saw to which the abrasive grains are attached is greatly reduced. Further, when the wire saw is bridged over the pulleys of the first and second guide mechanisms and sent out in the vertical direction and the ceramic is moved in the XY axis direction on the XY table, tension acts on the wire saw in the moving direction of the table. Then the wire saw tilts. Therefore, since the wire saw runs in an inclined state between the cutting portion and the pulley, the pulley is ground by the wire saw, and the ceramic cannot be cut stably for a long time. Moreover, the ceramic work piece is cut in the vertical direction with a wire saw and extracted into a predetermined shape such as a columnar shape to form a through portion such as a round hole in the ceramic work work, so that the cut or sliced ceramic falls. May be damaged.

Japanese Unexamined Patent Publication No. 2003-303728 (Patent Document 2) describes a step of producing a molded body of magnet powder, a step of processing the molded body using a wire saw on which abrasive grains are fixed, and a step of processing the molded body. A method for manufacturing a sintered magnet including a step of sintering is described, and in the processing step, the molded body is moved relative to the wire saw to slice the molded body, and the wire saw is used. On the other hand, it is also described that the molded body is relatively moved in a horizontal plane to pull the sliced portions apart in the vertical direction, and that the cutting liquid is applied to the contact portion of the molded body with the wire saw.

Japanese Patent Application Laid-Open No. 2005-268668 (Patent Document 3) states that when a raw material alloy powder containing a rare earth element is molded and the molded product is cut into a predetermined shape, it is substantially orthogonal to the cut surface of the molded product. It is described that the surface in at least one of the two directions is pressure-supported, and that the surface is cut by wire saw processing.

However, in these methods, the molded product is sliced in the vertical direction with a predetermined width, and the shape of the cut molded product is restricted to the plate-like shape. In particular, the sliced molded product may fall and be damaged, and in order to prevent the sliced molded product from falling over, a pressure support mechanism is required as described above. Further, if the cutting fluid adheres, there is a possibility that cracks during sintering and uneven performance of the sintered body due to poor structure may occur.

Japanese Patent Application Laid-Open No. 2013-63648 (Patent Document 4) describes a material containing silicon carbide in which a large number of cells are juxtaposed in the longitudinal direction across a cell wall by extrusion molding and an outer peripheral wall is formed on the side surface thereof. A method for cutting a honeycomb molded body is described in which a columnar honeycomb molded body is produced and the honeycomb molded body is cut to a predetermined length. In this method, the wavelength region 0. It is described that a cutting auxiliary groove is provided by a laser of 7 to 2.5 μm, and cutting is performed by a wire through the cutting auxiliary groove. Also in this method, the honeycomb molded body is cut at a predetermined length in the direction orthogonal to the length direction of the honeycomb molded body, and the honeycomb-shaped form is restricted.

It is also conceivable to cut the powder molded product with a contour machine (band saw device). However, since the contour machine uses a band saw, the powder compact can only be processed in a straight line.

JP-A-2003-165847 (Claims, FIG. 1) JP-A-2003-303728 (Claims, FIG. 1) JP-A-2005-268668 (Claims, FIG. 1) JP 2013-63648 (Claims, FIG. 1)

Therefore, an object of the present invention is to stably cut (or cut) a secondary molded product having a predetermined shape from a powder molded product as a primary molded product to produce a predetermined sintered body such as cemented carbide. A wire saw device useful for, a method of cutting a secondary molded body (or a cutting method) from a powder molded body (or compression molded body) using this device, and a sintered body (super) by sintering the secondary molded body. The purpose is to provide a method for producing cemented carbide, etc.).

Another object of the present invention is a wire saw device and a cutting method (or cutting method) useful for cutting (or cutting) a secondary molded body from a powder molded body into a non-plate shape (or a three-dimensional three-dimensional shape). ), And a method for producing a sintered body (cemented carbide, etc.) by sintering a secondary molded body having a three-dimensional three-dimensional shape.

Yet another object of the present invention is to damage the secondary molded body while preventing it from tipping over or falling even if the primary molded body is soft and brittle and the secondary molded body has a thin wall and / or a small diameter portion. Provided are a wire saw device capable of cutting (or cutting) accurately without any need, a method of cutting (or cutting) a secondary molded product using this device, and a method of manufacturing a sintered body (cemented carbide, etc.). There is.

Another object of the present invention is a wire saw device capable of producing a secondary molded body and a sintered body with high yield and productivity, and effectively reusing the generated chips or dust, using this device. It is an object of the present invention to provide a method for cutting out (or cutting) a secondary molded product, and a method for producing a sintered body (cemented carbide, etc.).

The present inventors have focused on the fact that in powder metallurgy, the processing efficiency of a sintered body is greatly reduced, and that the powder molded body (compression molded body) used for sintering is easy to process, but is soft, brittle and easily damaged. As a result of diligent studies to achieve the above-mentioned problems, instead of slicing and cutting the powder compact in the vertical direction with a wire saw, the wire saw is run in the horizontal direction (X-axis direction on the left and right) and the powder is formed. When the molded product (primary molded product) is moved at least in the Y-axis direction (depth direction) and the powder molded product is cut or sliced in the lateral direction in a dry manner, the secondary molded product (pre-molded product) is cut or cut in a stacked state. Since it can be sliced, the secondary molded body (pre-molded body) does not fall or fall, so not only is it hardly damaged, but unlike the wet cutting, the structure of the secondary molded body (pre-molded body) at the cut portion No fluctuation, especially when the powder molded body (primary molded body) is moved in the Y-axis direction and the Z-axis direction (height direction), damages the secondary molded body having a three-dimensional three-dimensional shape from the powder molded body. The present invention has been completed by finding that it can be cut or cut out with high accuracy and high yield and productivity without any problems.

That is, the device of the present invention is a device (wire saw device) for cutting a powder molded body (or a primary molded body) with a wire saw, and is a wire saw capable of traveling in the X-axis direction and the wire saw. On the other hand, it is provided with a table that is relatively movable in at least the Y-axis direction of the Y-axis direction and the Z-axis direction, and on which the powder molded product can be placed or held.

Such a wire saw device includes a cutting area in which the wire saw can travel in the X-axis direction (lateral direction), and a table that can move in the YZ-axis direction with respect to the wire saw in this cutting area. You may. Further, an advancing / retreating means for advancing / retreating the powder molded body placed or held on the table with respect to the wire saw in the Y-axis direction, and moving the powder molded body up / down in the Z-axis direction with respect to the wire saw. A control unit for controlling the vertical movement means and the vertical movement means and the vertical movement means for moving the powder molded body in the YZ axis direction (circumferential direction) around the wire saw is provided. May be good.

The powder molded product (or primary molded product) may be a molded product obtained by compression molding the raw material powder using a binder, if necessary, and may be a soft and brittle chalk-shaped molded product. The powder molded product may be a molded product before sintering by powder metallurgy, for example, a cemented carbide powder molded product. Such a powder molded product may have at least one property selected from the following (a), (b) and (c).

(A) Hardness 0.01 to 1 GPa
(B) Density ^{3 to 10} g / cm ³
(C) Folding force 0.1 to 50 MPa

The hardness can be measured with a measurement load of 9.8 N according to JIS Z 2244, and the density can be calculated from the volume and weight of the primary molded body measured by a physical method. The bending force can be measured according to the method specified in CIS (Japan Machine Tool Manufacturers Association (former Carbide Tool Association) standard) 026.

The present invention is a method of manufacturing a secondary molded product by cutting a powder molded product as a primary molded product with a wire saw. The wire saw is run in the X-axis direction, and the wire saw is placed on a table. A method (or cutting method) in which a placed or held powder molded product is relatively moved in at least the Y-axis direction of the Y-axis direction and the Z-axis direction, and the powder molded product is cut to produce a secondary molded product. Also includes.

In such a method, the operation of moving the powder molded product in the Y-axis direction and slicing (or cutting) the powder molded product from one end face to the other end face is performed at least once to form a thin sheet or plate. The secondary molded product of the above may be manufactured. Further, the powder molded body placed or held on the table may be moved in the Y-axis direction and the Z-axis direction with respect to the wire saw to cut out (or cut out) the secondary molded body having a three-dimensional three-dimensional shape. .. For example, the powder compact may be moved in the Y-axis direction and the Z-axis direction, and a plurality of secondary compacts may be cut out (or cut) along a cutting locus in a continuous form (one-stroke form) by a wire saw. The secondary molded product may be cut out from the powder molded product by forming a cutting locus in the manner of one-stroke writing. Further, the powder molded body placed or held on the table is moved to the wire saw in the Y-axis direction and the Z-axis direction, and a plurality of three-dimensional three-dimensional shaped secondary molded bodies are cut out adjacent to each other in the Y-axis direction. You may.

More specifically, in the method of the present invention, the powder compact is moved forward at least in the Y-axis direction with respect to the wire saw (A), and a predetermined first cutting start portion of the powder compact is formed. The first lateral cutting step (at least the step of cutting laterally) of cutting the powder molded product to the base point, and
(B) After (or in response to) the arrival of the cut portion at the first base point, the powder compact is moved forward in at least the Y-axis direction and moved in the Y-axis direction and the Z-axis direction to be secondary. A three-dimensional cutting step for cutting a powder molded product with a cutting locus corresponding to at least a part of the cross-sectional outline (cross-sectional shape) of the molded product.
(C) The first lateral cutting step and the three-dimensional cutting step are regarded as one cutting cycle, and this cutting cycle is repeated in the Y-axis direction while moving the powder molded product forward at least in the Y-axis direction, and at least the first step. A repetitive step for forming a plurality of cutting loci returning to the base point of 1 and cutting the powder compact by making the plurality of secondary compacts adjacent to each other in the Y-axis direction.
(D) After the three-dimensional cutting step of the final cutting cycle, a step of separating and recovering the secondary molded product may be included.

It should be noted that the powder compacts are cut at different height positions, and a plurality of rows of secondary compacts formed adjacent to each other in the Y-axis direction are formed at intervals in the Z-axis direction. A row of secondary moldings may be formed. For example, after cutting the powder molded product in the above step, the powder molded product may be cut at different height positions in the following embodiment (H1) or (H2).

(H1) The powder molded body is moved in the Z-axis direction, and the powder molded body is retracted in the Y-axis direction at a height position different from the first cutting end point of the powder molded body as the second cutting start portion to cut. The cycle is repeated in the opposite direction, and the powder molded body is cut laterally up to the second cutting end point of the powder molded body. (H2) The powder molded body is cut in the X-axis direction and the Y-axis direction while avoiding contact with the wire saw. And by moving in the Z-axis direction, the wire saw is positioned (initial position) on the side of the first cutting start portion of the powder molded body, and the height position different from the first cutting start portion is set as the second cutting start portion. The powder molded body is moved forward in the Y-axis direction, the cutting cycle is repeated in the forward direction, and the powder molded body is cut laterally up to the second cutting end point of the powder molded body.

The present invention further includes a method of manufacturing a sintered body by sintering a secondary molded product produced by the above method. This sintered body may be a cemented carbide.

In the present specification, the "X-axis direction" is used synonymously with the lateral direction, the "Y-axis direction" is used with the depth direction, and the "Z-axis direction" is used synonymously with the height direction. In addition, the "powder molded body" may be referred to as a powder compression molded body or a primary molded body, including a pre-sintered body (or a temporary sintered body) from which the binder has been removed, and may be cut or cut out from the "powder molded body". The molded product produced by the above is referred to as a "secondary molded product", and this "secondary molded product" may be referred to as a pre-molded product.

In the present invention, since the powder molded body (primary molded body) is cut at least in the lateral direction (X-axis direction) using a wire saw, the cut secondary molded body does not fall over, and the secondary molded body can be formed. It can be stably manufactured, and a predetermined sintered body such as cemented carbide can be efficiently manufactured. Further, since the powder molded body (primary molded body) can be moved in the YZ direction, a non-flat (or three-dimensional three-dimensional shape) secondary molded body is efficiently cut out (or cut) from the powder molded body. )it can. In particular, even if the primary molded body is soft and brittle and the secondary molded body has a thin wall and / or a small diameter portion, it is cut out (or accurately) without damaging the secondary molded body while preventing it from tipping over or falling. (Cut) is possible. Further, since it is cut with a wire saw, it is possible to manufacture a secondary molded product and a sintered body with high yield and productivity. Furthermore, since the chips or dust generated by the cutting process is an unsintered body, the chips or dust can be effectively reused.

FIG. 1 is a schematic front view for explaining the wire saw device of the present invention. FIG. 2 is a schematic side view of the device shown in FIG. FIG. 3 is a schematic perspective view showing a cutting state of the powder molded product by the apparatus shown in FIG. FIG. 4 is a schematic view showing a cutting locus of a powder molded product by a wire saw. FIG. 5 is a schematic view showing another cutting locus of the powder molded product by the wire saw and the holding member.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, if necessary.

The wire saw device (processing device) shown in FIGS. 1 to 3 includes a supply reel 2 for unwinding the wound wire saw 1, a take-up reel 3 for winding the wire saw unwound from the reel, and a winding reel 3. It is arranged between the supply reel 2 and the take-up reel 3, and includes a pair of guide reels 4 and 5 for guiding the wire saw 1 in the X-axis direction (lateral direction), and a pair of guide reels 4 Guide rolls 6a to 6d are arranged between the reels 2 and the take-up reels 3 and the guide rolls 6a to 6d, respectively, and a tension for adjusting the tension of the wire saw 1 is provided on the take-up reel 3 side. A pulley 7 is arranged. A cutting area is formed between the pair of guide reels 4 and 5 so that the wire saw 1 can travel in the X-axis direction (lateral direction). The guide rolls 6a and 6b adjacent to the pair of guide reels 4 and 5 may function as tension pulleys.

The supply reel 2 and the take-up reel 3 are each provided with a traverse mechanism (not shown), and the wire saw 1 is provided in the forward rotation direction (forward direction) from the supply reel 2 toward the take-up reel 3. In addition to being able to travel, the wire saw 1 can also travel in the reverse rotation direction (reverse direction) from the winding reel 3 toward the supply reel 2 after winding the wire saw 1 having a predetermined length.

Since the cemented carbide powder molded body 10 is cut by the wire saw 1, the powder molded body 10 can be placed or held on a table (work table) 11. In this example, the table 11 is provided with a holding member 12 for positioning the powder molded body 10 on the table 11, and is located on the peripheral edge of the table 11 (ends in the X-axis and Y-axis directions). , A recovery groove portion 13 for collecting chips is formed.

The table (work table) 11 is movable in the Y-axis direction (depth direction) and the Z-axis direction (vertical direction) with respect to the wire saw 1 that can travel in the X-axis direction (horizontal direction). That is, a guide portion 14 extending in the Y-axis direction is interposed between the table 11 and the support base 15, and is along the guide portion 14 by advancing / retreating means (not shown) for advancing / retreating in the Y-axis direction. The table 11 can be moved. Further, the powder molded body 10 can be moved up and down in the Z-axis direction with respect to the wire saw 1 by a vertical movement means (elevating means) (not shown) capable of moving the support base 15 up and down. In this example, a pair of rail portions 14a and 14a are formed on the support base 15 along the Y-axis direction, and can be arranged on the bottom surface of the table 11 in a traveling path between the pair of rail portions 14a and 14a. A traveling portion 14b extending in the Y-axis direction is formed, and the pair of rail portions 14a and 14a and the traveling portion 14b form a guide portion 14.

In this example, the advance / retreat unit provided with the advance / retreat means is arranged on the vertically moving unit provided with the vertically moving means via the support base 15, and the vertically moving unit and the advancing / retreating unit are arranged. The mobility and movement direction (Y-axis direction and / or Z-axis direction) of the powder molded body 10 placed or held on the table 11 are controlled by a control unit (numerical control (NC) device) for controlling the operation. doing. In the control unit, a conventional drive unit (for example, a servomotor and / or a cylinder capable of multi-axis synchronous control) is used, and a numerical value is input as a variable to perform shape processing according to a program (macro program). The operation of 11 may be controlled.

Further, the apparatus also includes a nozzle 16 capable of blowing air in order to remove dust generated when the powder molded body 10 is cut by the wire saw 1, and a duct (or) for collecting scattered dust. It also has a dust collection unit) (not shown).

In such a device, the powder molded body 10 can be moved in the Y-axis direction (depth direction) and the Z-axis direction (height direction) with respect to the wire saw 1 traveling in the X-axis direction (lateral direction). Various forms of secondary compacts can be cut out from the soft and brittle powder compact 10 without using a liquid or a cutting liquid. For example, in the above example, the operation of moving the table 11 in the Y-axis direction and the operation of moving the table 11 in an arc shape (or ring shape) in the YZ axis direction are repeated with the wire saw 1 as the center. As a result, a plurality of columnar secondary molded bodies 17 can be cut out adjacent to each other in the Y-axis direction. Moreover, since the cut out secondary molded body 17 is supported by the receiving surface of the arc-shaped cut portion, the secondary molded body 17 can be manufactured with high dimensional accuracy without being damaged. Therefore, the secondary molded product 17 can be manufactured with high yield and productivity. Moreover, since the dust generated by cutting with the wire saw 1 can be efficiently collected in the dust collecting unit by the air from the nozzle 16, the amount of dust scattered by the chips is extremely small, and the scattering of the chips can be remarkably suppressed. Therefore, even a powder molded product containing a specific chemical substance such as cobalt can greatly improve the working environment. Further, the chips collected by the dust collecting unit and the collecting groove portion 13 can be effectively reused for the powder molded product.

The form of the traveling path of the wire saw is not particularly limited, as long as the wire saw can travel in the X-axis direction (lateral direction) in the cutting region of the powder molded product. The tension pulley can be arranged not only on the take-up reel 3 side but also at an appropriate position on the traveling path of the wire saw, and the guide rolls 6a and 6b adjacent to the pair of guide reels 4 and 5 may function as the tension pulley.

The wire saw can usually be formed of a wire core wire (main body) and abrasive grains (hard abrasive particles such as diamond particles, silicon nitride, and alumina) attached or fixed (electrodeposited) to the wire core wire. The wire core wire may be formed of, for example, a hard steel wire (piano wire), a nickel alloy (alloy such as Fe / Ni alloy), a refractory metal (tungsten, molybdenum, etc.), a nylon (aramid) fiber bundle, or the like. , Usually, it is often a piano wire. The average diameter (wire diameter) of the wire core wire is not particularly limited and can be selected according to the type of powder molded body, the accuracy of the outer shape of the secondary molded body, etc., for example, 0.01 to 1 mm, preferably 0.05 to. It may be about 0.5 mm (for example, 0.1 to 0.3 mm), more preferably about 0.12 to 0.25 mm (for example, 0.15 to 0.2 mm). The average wire diameter of the wire saw may be, for example, 0.1 to 0.5 mm, preferably 0.15 to 0.4 mm, and more preferably 0.2 to 0.3 mm. Further, in order to prevent grinding by abrasive grains, the contact portion (for example, the peripheral surface) with the wire saw in the pulley or guide roll is covered with a soft rubber or foam such as urethane rubber or its foam. You may.

The tension of the wire saw can be selected according to the type of the powder molded body and the wire core wire, and is, for example, about 30 to 70 N, preferably 35 to 65 N, and more preferably 40 to 60 N (for example, 45 to 55 N). It may be.

In the reciprocating travel in the forward and reverse directions of the wire saw (forward rotation direction and reverse rotation direction of the supply reel 2), the core wire of the wire saw may be gradually fed out to suppress twisting of the wire saw.

The holding member 12 is not always necessary for a powder molded body having a large weight, such as the cemented carbide powder molded body 10. Further, the form of the holding member 12 is not particularly limited as long as it can be in contact with the powder molded body 10 to regulate the movement of the powder molded body 10, and may be pin-shaped, plate-shaped, prismatic, or the like that can be erected on a table. It may be a prismatic shape or a frame shape (U-shaped or the like) that can be horizontally installed on the table. The holding member 12 may be a member that can be fixed or temporarily fixed to the table 11, for example, metal, or may be formed by a removable means such as a magnet.

Further, the recovery groove portion 13 is not always necessary. Further, the collection groove portion 13 for collecting chips may be formed at the end portion of the table 11 in the X-axis direction and / or the Y-axis direction.

In order to cut or cut out a secondary molded body having a predetermined form from the powder molded body, the wire saw and the powder molded body (or table) may be relatively movable in a predetermined direction, and are usually used in a wire saw. On the other hand, in many cases, the powder molded body (or table) can be moved in at least the Y-axis direction (particularly the Y-Z-axis direction) of the Y-axis direction and the Z-axis direction. In particular, when the powder molded body (or table) is moved at least in the Y-axis direction, the secondary molded body cut on the cut surface can be supported, so that the secondary molded body can be manufactured stably and with high accuracy.

A guide mechanism (guide unit), a cylinder mechanism, etc. can be used to move the table in the Y-axis direction and the Z-axis direction, and motors (stepping motor, servomotor, etc.) are used to drive these mechanisms. Hydraulic pressure etc. can be used. Further, at least two-axis synchronously controllable (for example, multi-axis synchronously controllable) motors may be used, and the table may be moved in the Y-axis direction and the Z-axis direction by the control unit according to a predetermined program. By program control, secondary molded bodies of various shapes can be manufactured, and secondary molded bodies can be manufactured with high yield and productivity.

The form of the guide portion interposed between the table 11 and the support base 15 is not particularly limited, and the rail portion (rail portion such as the V-groove-shaped rail portion extending in the Y-axis direction) formed on the support base 15 and the above-mentioned It can be formed by a traveling portion formed on the table 11 and capable of traveling along the rail portion (a traveling portion having a form corresponding to the V groove and extending in the Y-axis direction, etc.).

Since the powder molded product (primary molded product) is not sintered, it is characterized by being soft and brittle. Such a powder molded product often has, for example, at least one property (particularly all properties) selected from the following (a), (b) and (c).

(A) Hardness 0.005 to 1 GPa (for example, 0.001 to 0.1 GPa (for example, 0.01 to 0.7 GPa), preferably 0.03 to 0.03 to 1 GPa) measured at a load of 9.8 N according to JIS Z 2244. About 0.5 GPa, more preferably 0.05 to 0.3 GPa (for example, 0.1 to 0.3 GPa)) (b) Measured or calculated by a physical method (dimensions in the X-axis, Y-axis and Z-axis directions) Density 2-10 g / cm ³ (eg 3-10 g / cm ³ , preferably 3-9 g / cm ³ (eg 5-8 g / cm ³ ), more preferably 6 calculated based on the volume and weight. ~ 7.5 g / cm ³ ) Approx. (C) CIS (Japan Machine Tool Manufacturers Association (former Carbide Tool Association) standard) 0.1 to 50 MPa (for example, 0) It may be about 5 to 25 MPa, preferably 0.7 to 10 MPa (for example, 1 to 5 MPa), and more preferably 1 to 3 MPa.

The type of powder molded body (primary molded body) is not particularly limited, and the molded body before sintering (compression molded body) used for powder metallurgy, for example, metal oxidation of ceramic powder molded body (alumina, titania, zirconia, etc.) Materials, metal nitrides such as metal nitrides such as aluminum nitride and boron nitride, compression moldings of powders such as metal carbides such as silicon carbide), magnet powder moldings (neodium Nd, pseudosim Pr, cisprosium Dy, etc.) It may be a magnet powder molded body containing a rare earth element), a cemented carbide powder molded body, or the like. A preferred powder molded product is a cemented carbide powder molded product.

Such a cemented carbide powder molded product (primary molded product) usually contains tungsten carbide WC and components (cobalt Co and / or nickel Ni, etc.) that form a liquid phase by sintering and form a bonded phase. It contains, and if necessary, carbon source C (carbon black, carbon nanocoil, carbon nanotube, etc.) may be contained, or a component that is inevitably mixed may be contained. The bonded phase includes, for example, Group IV elements (titanium Ti, zirconium Zr, etc.), Group V elements (vanadium V, niobium Nb, tantalum Ta, etc.), Group VI elements (chromium Cr, molybdenum Mo, tungsten W, etc.). Etc.), Group VII elements (manganese Mn, renium Re, etc.) and the like may be contained. The preferred binding phase may contain at least cobalt.

These components have a powdery granular form. The average particle size of tungsten carbide WC may be, for example, about 0.1 to 15 μm (for example, 0.12 to 12 μm, preferably 0.2 to 10 μm), and the average particles of cobalt Co and / or nickel Ni. The diameter is not particularly limited because it melts to form a bonded phase, and may be, for example, about 0.1 to 5 μm (for example, 0.5 to 3 μm, preferably 1 to 2.5 μm). The ratio of cobalt Co and / or nickel Ni to 100 parts by weight of the entire cemented carbide component is 0 to 40 parts by weight, preferably 0.5 to 35 parts by weight, and more preferably about 1 to 30 parts by weight. It may be.

The average particle size of vanadium V and / or chromium Cr is not particularly limited because it dissolves in the bonded phase, and is, for example, 0.1 to 5 μm (for example, 0.5 to 3 μm, preferably 1 to 2.5 μm). ) May be the case. Periodic Table The ratio of Group IV to Group VII elements (vanadium V and / or chromium Cr, etc.) is 0 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the entire superhard alloy component. It may be about 0.2 to 2 parts by weight, more preferably 0.2 to 2 parts by weight.

Such components are required in powdery granular form with binders, especially binders that can be removed by heating, such as linear or branched aliphatic hydrocarbons such as paraffin, wax or wax, polyethylene glycol and the like. Therefore, alcohols such as ethanol and / or benzines may be added, mixed and dried, and compression-molded. The ratio of the binder may be about 0 to 20 parts by weight, preferably 0.1 to 10 parts by weight (for example, 0.2 to 7 parts by weight) with respect to 100 parts by weight of the powder or granular material.

The powder molded product (primary molded product) can be prepared by compression molding such a mixture (powdered mixture). The molding pressure of the mixture may be, for example, about 50 to 200 MPa, preferably about 75 to 150 MPa.

Such a compression molded product (powder molded product) may contain the binder, for example, under normal pressure or reduced pressure, 100 to 1000 ° C. (preferably 300 to 900 ° C., more preferably 500 to 800 ° C.). The binder may be removed by heating to a degree to prepare a powder molded product (pre-sintered product (or temporary sintered body)) containing no binder. The hardness of the surface of such a pre-sintered body (or a temporary sintered body) may be slightly larger than that of the unsintered body.

The primary molded body (powder molded body) is often a thick-walled or block-shaped molded body.

In the method of the present invention, the wire saw is run in the X-axis direction, and the powder molded body (primary molded body) placed or held on the table is placed on or held on the table with respect to the wire saw at least in the Y-axis direction and the Z-axis direction. It can be moved relatively in the Y-axis direction to cut the powder molded product to produce a secondary molded product. The form of the secondary molded body is not particularly limited, and may be, for example, a two-dimensional shape such as a sheet or a plate, and a pin-shaped or rod-shaped or columnar (square columnar, round bar-shaped, etc.) or tertiary shape having an indefinite cross section. It may have an original three-dimensional shape, or a form in which the same or different predetermined cross-sectional shape portions are connected (a form in which block portions (prisms, round bars, etc.) are connected in a thin-walled portion, for example, a beaded shape), etc. It may be.

For example, when a powder compact (or table) is moved in the Y-axis direction and sliced (cut) from one end face to the other end face of the powder compact, the diameter of the wire saw is small, so that it is in the form of an extremely thin sheet or A plate-shaped secondary molded product can be manufactured. Moreover, the table is moved in the + Y-axis direction (forward direction) to slice (cut) the powder molded body from one end face to the other end face, and the height position of the table is changed (moved in the Z-axis direction). The operation of slicing (cutting) the powder molded body from the other end face to one end face by moving the table in the −Y axis direction (backward direction) is repeated, and the position in the height direction (Z axis direction) is changed for powder molding. When the body is sliced in the lateral direction (Y-axis direction), the sliced secondary compacts can be supported in a plane in a stacked state even if the thickness is extremely small, so that the secondary compacts can be stably and highly accurately supported with high productivity. And can be manufactured by yield. For example, in the past, since the tool width (thickness) was as large as about 0.7 to 1 mm, only a plate-shaped secondary molded product having a thickness of about 1.5 mm could be manufactured, but in the present invention, the thickness is 0.2 to 0. Even a plate-shaped secondary molded product of about 0.6 mm (for example, 0.3 to 0.5 mm) can be manufactured stably and in a stacked state, and the productivity and yield of the secondary molded product can be dramatically improved. ..

When the movement of the table in the Y-axis direction and the movement in the Z-axis direction are regarded as one cutting cycle (1 slice cycle), this cycle can be repeated at least once (preferably a plurality of times), and the cycle can be repeated. When repeating a plurality of times, for example, the movement of the table in the + Y-axis direction, the movement in the Z-axis direction, and the movement in the −Y-axis direction may be used.

It is also conceivable to form a thin-walled sheet by press molding. However, in press molding, it is extremely difficult to form a thin and uniform layer of powder or granular material in a mold, and there is a limit in preparing a brittle and soft thin-walled sheet. On the other hand, in the present invention, even if the powder molded product (for example, an unsintered primary molded product) is brittle and soft, a thin secondary molded product can be easily produced.

By moving the powder molded body placed or held on the table with respect to the wire saw in the Y-axis direction and the Z-axis direction, a non-flat (or three-dimensional three-dimensional shape) secondary molded body can be cut out. .. For example, when the powder compact is moved in the Y-axis direction and the Z-axis direction and the secondary compact is cut in the form of a non-regular cutting locus, for example, a wavy shape or a bent shape, they are fitted or attached to each other. It is also possible to obtain a pair of secondary molded articles having possible mating surfaces.

Further, the powder compact (or table) may be moved in the Y-axis direction and the Z-axis direction, and a plurality of secondary compacts may be cut out by a cutting locus with a wire saw in a continuous form (one-stroke form). That is, by moving the powder molded product (or table) in the Y-axis direction and the Z-axis direction, secondary molded products having various cross-sectional shapes are regularly or irregularly cut out or manufactured from one powder molded product. At the same time, secondary molded bodies having different cross-sectional shapes (or thicknesses) can be cut out regularly or irregularly from one powder molded product. More specifically, by moving the table in the Y-axis direction and the Z-axis direction, a rod-shaped or columnar body (square bar, round bar, etc.) can be cut out from the powder molded body regardless of the diameter. it can. In particular, an ultrafine rod (such as a round rod), for example, a rod having a diameter of about 0.5 to 1.5 mmΦ (for example, 0.5 to 1 mmΦ) can be cut out. Even in the preparation of such a secondary molded product, since the secondary molded product is supported by the cut portion of the powder molded product, it is not damaged while being prevented from falling.

Further, the powder molded body placed or held on the table is moved to the wire saw in the Y-axis direction and the Z-axis direction, and a plurality of three-dimensional three-dimensional shaped secondary molded bodies are regularly or irregularly Y-shaped. It can also be cut out adjacent to the axial direction and / or the Z-axis direction. The morphology of the secondary compacts adjacent in such a direction may be the same or different.

The secondary molded product adjacent to the Y-axis direction includes, for example, the following first lateral cutting step (1), three-dimensional cutting step (2), repeating step (3), and separation and recovery step (4). Can be cut out from the powder molded product.

(1) With respect to the wire saw, the powder compact is moved or moved forward at least in the Y-axis direction to cut the powder compact from the first cutting start portion of the powder compact to a predetermined first base point. 1 lateral cutting step (for example, a step of cutting at least laterally to a predetermined depth)
(2) With the first base point as the base point (or in response to the arrival of the cut portion at the first base point), the powder compact is moved in the Y-axis direction and the Z-axis direction (for example, at least in the Y-axis direction). (Move in the Y-axis direction and the Z-axis direction while moving forward), for cutting the powder molded body with a cutting locus corresponding to at least a part of the cross-sectional outline (cross-sectional shape) of the secondary molded body. Three-dimensional cutting step (3) The first lateral cutting step and the three-dimensional cutting step are regarded as one cutting cycle, and this cutting cycle is repeated in the Y-axis direction while moving the powder molded body forward at least in the Y-axis direction. To form a plurality of cutting loci (plural closed loci or loop loci) returning to at least the first base point, and to cut the powder molded body by adjoining the plurality of secondary molded bodies in the Y-axis direction. (4) A step of separating and recovering the secondary molded body after the three-dimensional cutting step of the final cutting cycle.

In particular, while moving the powder compact in the Y-axis direction (forward and / or backward movement) and moving in the Z-axis direction (up and / or down), a closed cutting locus (plural) with a wire saw in the manner of a single stroke. By forming a closed locus or a loop-shaped locus), the secondary molded body can be efficiently cut out from the powder molded body. The secondary molded body can be formed by moving the powder molded body in the Y-axis direction and the Z-axis direction with the wire saw as a reference (or center) according to the cross-sectional shape of the secondary molded body.

Hereinafter, the operation of the apparatus and the cutting method (or cutting method) will be described in detail with reference to the attached drawings. Note that FIG. 4 shows an example of cutting out a secondary molded body having a round bar shape (circular cross section). In FIG. 4A, a plurality of three-dimensional three-dimensional shaped secondary molded bodies are cut out adjacent to each other in the Y-axis direction in the following aspect (A).

In the method of aspect (A), as shown by the solid line (1a), the powder molded body 10 is moved forward (moved in the + Y-axis direction) in the Y-axis direction with respect to the wire saw to make the first powder molded body. The first lateral cutting step of cutting the powder compact 10 in the lateral direction from the cutting start portion 21 to the predetermined first base point 22.
(2a) After the cut portion of the wire saw reaches the first base point 22, the powder molded body 10 is moved forward in the Y-axis direction and moved in the Y-axis direction and the Z-axis direction to move the secondary molded body 27. A cutting locus corresponding to the cross-sectional outline (cross-sectional shape) and reaching a predetermined second base point 23 facing the first base point 22 in the Y-axis direction (in this example, a first semi-arc-shaped locus). ) 24, the first semi-closed (or semi-looped) cutting step of cutting the powder compact 10
(3a) The (1a) first lateral cutting step and (2a) first semi-closed semi-loop cutting step are regarded as one cutting cycle, and this cutting cycle is used for the powder molded body 10 in the Y-axis direction. The first repeating process (advancing direction repeating process) that repeats in the Y-axis direction while moving forward
(4a) After reaching the second base point 23 in the (2a) first semi-closed (semi-loop) cutting step of the final cutting cycle, the powder compact 10 is moved forward in the Y-axis direction to perform powder molding. It includes a second lateral cutting step of cutting the powder molded body 10 in the lateral direction up to the first cutting end point 25 of the body 10.

By such a step, a semi-closed (or semi-looped) cutting locus can be formed adjacent to the Y-axis direction (in this example, the first semi-arc shape is the Y-axis via a flat locus portion). It forms a cutting locus adjacent to the direction).

Further, after such a step, the powder molded body 10 is retracted in the Y-axis direction to form a semi-closed (or semi-looped) cutting locus in the direction opposite to the above, by repeating the step. It is possible to form a cutting locus in which a plurality of secondary molded bodies 27 are cut out. That is,
(5a) As shown by the broken line, after the second lateral cutting step, the powder molded body 10 is moved backward (moved in the −Y axis direction) in the Y-axis direction to perform the second lateral cutting step. The process of moving the cut portion to the second base point 23 along the cut locus, and
(6a) After the cut portion reaches the second base point 23, the powder molded body 10 is moved in the Y-axis direction and the Z-axis direction while retreating in the Y-axis direction to form the cross-sectional outline of the secondary molded body 27. A cutting locus that corresponds and returns from the second base point 23 to the first base point 22 (in this example, a second semicircular locus that is continuous with the first semicircular locus and forms a closed loop locus). ) 26, a second semi-closed (semi-loop) cutting step of cutting the powder molded body 10 and
(7a) (4a) The second lateral cutting step and (6a) the second semi-closed semi-loop cutting step are regarded as one cutting cycle, and this cutting cycle is performed by moving the powder compact 10 in the Y-axis direction. A second repeating process (reverse direction repeating process) that repeats while moving backward,
(8a) After reaching the first base point 22 in the (6a) second semi-closed semi-loop cutting step of the final cutting cycle, the powder compact 10 is moved backward in the Y-axis direction to perform the first lateral movement. By the step of moving the powder compact 10 laterally along the cutting locus of the directional cutting step (up to the first cutting start portion of the powder compact 10), the plurality of secondary compacts 27 are moved in the Y-axis direction. The powder molded body 10 cut out adjacent to the can be formed.

(9a) Through such a step, the secondary molded body 27 can be formed adjacent to each other in the Y-axis direction, and the secondary molded body 10 is separated along the cut surface by the separation step, which is secondary molding without damage. The body can be separated and recovered.

The first lateral cutting step (1a) corresponds to the first lateral cutting step (1), and the first semi-closed cutting step (2a) corresponds to the three-dimensional cutting step (2). First repeating step (3a), second lateral cutting step (4a), moving step (5a), second semi-closed cutting step (6a), second repeating step (7a) and moving step ( 8a) corresponds to the repeating step (3), and (9a) the separating step corresponds to the separation and recovery step (4).

In the aspect (A), the powder molded body 10 is moved forward on one side (upper side) with the forward movement of the powder molded body 10 in the Y-axis direction about the reference line connecting the first base point 22 and the second base point 23. A semi-closed first cutting locus is formed adjacent to each other in a convex (mountain-shaped) form, and a concave shape (lower side) is formed on the other side (lower side) as the powder molded body 10 moves backward in the Y-axis direction. A semi-closed second cutting locus is formed adjacent to each other in the form of a valley), and a loop-shaped closed cutting locus is formed by the first cutting locus and the second cutting locus. The method of forming the cutting locus is not particularly limited.

In the aspect (B) shown in FIG. 4 (b), the solid line is drawn with the forward movement of the powder molded body 10 in the Y-axis direction about the reference line connecting the first base point 22 and the second base point 23. As shown, a semi-closed first cutting locus 24 is formed adjacent to each other on both sides (upper and lower sides) in the form of a waveform (sine curve), and the powder molded body 10 recedes in the Y-axis direction. Along with the movement, as shown by the broken line, a semi-closed second cutting locus 26 is formed adjacent to each other in the form of a waveform (sine curve) on both sides (upper side and lower side), and the first A loop-shaped closed cutting locus is formed by the cutting locus and the second cutting locus.

The secondary molded body does not have to be formed by reciprocating the powder molded body 10 in the Y-axis direction, and may be formed by moving the powder molded body 10 forward or backward in the Y-axis direction.

In FIG. 4C, a plurality of three-dimensional three-dimensional shaped secondary molded bodies are cut out adjacent to each other in the Y-axis direction in the following aspect (C). That is, in the method of aspect (C), the powder molded body 10 is moved forward (moved in the + Y-axis direction) in the Y-axis direction with respect to the wire saw (1b), and a predetermined first cutting start portion 21 is used. The first lateral cutting step of cutting the powder compact 10 laterally up to the base point 22 of 1 and
(2b) After (or in response to) the arrival of the cut portion of the wire saw to the first base point 22, the powder compact 10 is moved forward and backward in the Y-axis direction while moving forward and backward in the Y-axis direction and the Z-axis. A closed shape (loop) that cuts the powder molded body 10 with a closed form cutting locus 33 that moves in the direction, corresponds to the cross-sectional outline (cross-sectional shape) of the secondary molded body 10, and returns to the first base point 22. Shape) Cutting process and
(3b) (1b) The first lateral cutting step and (2b) closed (loop-shaped) cutting step are regarded as one cutting cycle, and this cutting cycle moves the powder molded body 10 forward in the Y-axis direction. While repeating the process repeating in the Y-axis direction,
(4b) After reaching the first base point 22 in the (2b) closed (loop-shaped) cutting step of the final cutting cycle, the powder compact 10 is moved forward in the Y-axis direction to move the powder compact 10 forward to the first powder compact 10. It includes a second lateral cutting step of cutting the powder molded body 10 in the lateral direction up to the cutting end point portion 25 of the above.

The second lateral cutting step (4b) is included in the separation / recovery step (4), and in this separation / recovery step (4), the secondary molded body 27 formed adjacent to the Y-axis direction is powder-molded. It can be recovered by extracting it from the body 10.

Further, if the wire saw is moved again along the cut portion (cutting locus) formed in the powder molded body 10, the dimensional accuracy of the secondary molded body may be slightly lowered. In such a case, the secondary molded body may be formed without overlapping the cutting loci.

In FIG. 4D, a plurality of three-dimensional three-dimensional shaped secondary molded bodies are cut out adjacent to each other in the Y-axis direction in the following aspect (D). In the method of aspect (D), the powder molded body 10 is moved forward in the Y-axis direction with respect to the wire saw (1c), and a predetermined first base point 22 is moved from the first cutting start portion 21 of the powder molded body 10. The first lateral cutting step of cutting the powder molded product 10 in the lateral direction, and
(2c) After the cut portion reaches the first base point 22 (or in response to the arrival), the powder molded body 10 moves forward in the Y-axis direction (moves in the + Y-axis direction) and moves in the Z-axis direction. It moves in the Z-axis direction (upward movement) while moving in the Y-axis direction (moving in the -Y-axis direction) while moving (downward movement), and corresponds to the cross-sectional outline (cross-sectional shape) of the secondary molded body. A closed (or loop) cutting step of cutting the powder molded body 10 with a cutting locus 24 in a closed form (in this example, an arc shape, a circular shape, or a loop shape) returning to the first base point 22.
(3c) After (or in response to) the re-arrival of the cut portion to the first base point 22, the powder compact 10 is moved forward in the Y-axis direction and moved in the Z-axis direction (downward movement). To a predetermined second base point 23 that faces the first base point 22 in the Y-axis direction and is located forward (+ Y-axis direction) from the facing portion of the cut locus 24 in the closed form (arc-shaped form). It includes a semi-closed (or semi-looped) cutting step of cutting the powder molded body 10 with a semi-closed (semi-looped) cutting locus 28.

In this example, the semi-closed (semi-looped) cutting locus 28 is formed with a radius of curvature larger than the radius of curvature of the closed locus (arc-shaped) cutting locus 24. That is, in the (3c) semi-closed cutting step, the locus is similar to the closed locus 24 corresponding to the cross-sectional outline of the secondary molded body 27 and deviates upward from the upper cutting locus 24. A semi-closed (semi-looped) cutting locus 28 is formed in the above.

Further, in the cutting method of the aspect (D), (4c) the first lateral cutting step, the closed (loop) cutting step, and the semi-closed (semi-loop) cutting step are combined into one cutting cycle. After the cut portion reaches the second base point 23 in the repeating step of repeating this cutting cycle in the Y-axis direction and the (3c) semi-closed cutting step of the (5c) final cutting cycle, the powder compact 10 is Y. It includes a second lateral cutting step of laterally cutting the powder molded body 10 up to the first cutting end point 25 of the powder molded body 10 by moving forward in the axial direction.

In the aspect (D), the three-dimensional cutting step (2) can be formed by the closed (or loop) cutting step (3b) and the semi-closed (or semi-loop) cutting step (3c).

In the aspect (D), the powder molded product is cut in a loop shape with a closed cutting locus that returns to the first base point to generate a secondary molded product having a predetermined shape. Along the loop-shaped cutting locus or loop to the step and the portion of the secondary molded body facing the first base point in the Y-axis direction after the cut portion returns to the first base point. After the semi-loop cutting step of cutting in a similar shape that deviates from the shape cutting locus and the semi-loop cutting step, the powder compact is moved or moved forward in the Y-axis direction to perform cutting. It may include a transverse cutting step. Further, in the (3c) semi-closed cutting step, the loop-shaped cutting locus may be cut in a similar shape, and for example, the closed-shaped cutting locus corresponding to the cross-sectional outline of the secondary molded body 27 may be cut. A semi-closed (semi-loop-shaped) cutting locus 28 may be formed with a locus similar to the 24 and deviating from the cutting locus 24 (for example, a locus deviating downward).

In the above example, the secondary molded body is formed in the form of a rod-shaped body having a circular cross section, but the secondary molded body is not limited to the circular cross section, and any form such as a polygonal cross section, a star shape, or an elliptical shape is formed. Can form a secondary molded body.

Further, in the above example, in the lateral cutting step (first and second cutting steps, cutting step from the first base point to the second base point), the powder molded body is moved in the Y-axis direction. Although it is cut linearly, the powder compact may be moved at least in the Y-axis direction, and may be moved in the Z-axis direction in addition to the Y-axis direction to cut non-linearly (a form such as meandering or bending). You may. Further, if necessary, after cutting the predetermined secondary molded body, the powder molded body is moved in the Z-axis direction to shift to the cutting locus of the adjacent secondary molded body with a cutting locus such as a U shape. You may.

The cutting locus is not particularly limited, and includes a cutting locus of a plurality of secondary molded bodies and a transition cutting locus in which the cutting locus shifts from the cutting locus of one secondary molded body to an adjacent secondary molded body. It often forms a continuous form of cutting locus.

Further, in the powder molded body, the plurality of secondary molded bodies may be formed in a single row form in the Y-axis direction, or may be formed in a plurality of rows. For example, after repeating the cutting cycle in the Y-axis direction to reach the first cutting end point in the Y-axis direction (for example, the cutting end point facing the first cutting start part of the powder compact), the following By cutting the powder compacts at different height positions in the aspect of (H1) or (H2), a plurality of rows of secondary compacts formed adjacent to each other in the Y-axis direction are formed in the Z-axis direction. A plurality of rows of secondary molded bodies can be formed in the form formed at intervals.

(H1) After moving the powder molded body forward in the Y-axis direction to form a secondary molded body from one end face (cutting start portion side) of the powder molding body toward the other end face (cutting end point side). , A method of retreating a powder molded product in the Y-axis direction and repeating an operation (cutting cycle) of forming a secondary molded product from the other end face toward one end face. In this method, the powder molded body is moved in the Z-axis direction (height), and a height position different from that of the first cutting end point is set at the second cutting start part (the first cutting end point of the powder molded body). The powder molded body can be moved backward in the Y-axis direction as a cutting start portion having the same end face as the above but having a height position different from that of the first cutting end end portion, and the cutting cycle can be repeated in the opposite direction.

(H2) A method of repeating an operation (cutting cycle) of forming a secondary molded body from one end face (cutting start portion side) to the other end face (cutting end point side) of the powder molded body. In this method, the powder molded body is moved in the Z-axis direction (height), the powder molded body is moved backward in the Y-axis direction and the Z-axis direction while avoiding contact with the wire saw, and the first cutting is performed. The powder molded body can be moved forward in the Y-axis direction with a height position different from that of the first cutting start portion on the side surface on the start portion side as the second cutting start portion, and the cutting cycle can be repeated in the forward direction.

Of these aspects, aspect (H1) is often used.

In the above example, the example in which the secondary molded body is cut out adjacent to each other in the Y-axis direction of the powder molded body is mainly described, but the powder molded body is moved in the Y-axis direction and the Z-axis direction. The secondary molded body may be cut out, and if necessary, the secondary molded body may be cut out adjacent to each other in the Z-axis direction (height direction) of the powder molded body.

Further, in the present invention, it is also possible to cut out an unnecessary portion from the powder molded product in the manner of one-stroke writing to produce a secondary molded product in the form of hollowing out. For example, as shown in FIG. 5, in a state where the powder molded body 30 is held by the holding member 32 on the table (not shown), the wire saw 1 is passed through the insertion hole 31 formed in the powder molded body 30. The powder molded body 30 (and the table) is moved in the Y-axis direction and the Z-axis direction to be centered on a predetermined square frame, and the corners of the central square frame are adjacent to the corners of the square frame. A plurality of prismatic molded bodies 37 having a quadrangular cross section can be cut out from the cutting locus 34 to obtain a hollow molded body (secondary molded body that has been punched) 38. This hollow molded body can be sintered to obtain a sintered body.

When the cutting process is performed using the insertion hole 31 as the start hole, the punching process can be performed without a break, and the punched secondary molded body can be prepared. Therefore, the shape of the die of a mold such as a semiconductor can be approached, the man-hours and time required for precision machining can be shortened, and the mold can be formed accurately.

As described above, in the present invention, various forms of secondary molded articles can be produced. In particular, when the powder compact is cut in a one-stroke manner or manner (or in a continuous cutting locus), the secondary compact can be produced efficiently, with high productivity, and with a high yield.

A sintered body can be manufactured by shaping and sintering the secondary molded body cut out from the powder molded body, if necessary. Sintering of the secondary molded product can be performed by a conventional method, for example, by heating at a temperature of about 1000 to 3000 ° C., depending on the type of the molded product. For example, the secondary molded product of the magnet powder molded product can be sintered at a temperature of about 1000 to 1300 ° C. (for example, 1000 to 1150 ° C.), and the secondary molded product of the cemented carbide powder molded product is, for example, 1200 to 1200. It can be sintered at a temperature of about 1600 ° C. (for example, 1.25 to 1550 ° C.). The sintering time may be, for example, about 5 minutes to 48 hours (for example, 1 to 24 hours) depending on the sintering apparatus. In addition, sintering may be performed under reduced pressure (or vacuum), and may be performed under normal pressure or pressure. By such sintering, a sintered body having high dimensional accuracy can be manufactured with high productivity and yield.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
A block-shaped compression molded body (length 50 x width 100 x height 200 mm) containing powdered tungsten carbide WC, powdered cobalt Co, and paraffin is heated to 700 ° C. under reduced pressure to remove paraffin. , A powder molded body was prepared. When measured with JIS Z 2244 (measured load 9.8 N), the hardness of the powder molded product was 0.23 GPa, and the density of the powder molded product calculated from the volume and weight calculated based on the dimensions was 7.0 g / cm ³ The bending resistance of the powder molded product measured by CIS 026 was 2.2 MPa.

This powder molded body was placed on the table shown in FIG. 1, and a wire saw (average diameter 0.25 mm) in which diamond abrasive grains were electrodeposited on a piano wire (average diameter 0.18 mm) was used, as shown in FIG. 4 (d). A round bar-shaped secondary molded body (diameter 5 mmΦ) was formed adjacent to each other in the vertical and horizontal directions with the cut locus shown. The distance between the arc-shaped cutting locus 24 and the second base point 23 was set to 0.5 mm, and the distance between the second base point 23 and the first base point 22 was set to 0.6 mm in the adjacent secondary molded product. .. By such an operation, 100 round bar-shaped secondary compacts could be prepared in 1 hour. In the conventional method, it took 8 hours to prepare 100 round bar-shaped secondary molded products.

The obtained round bar-shaped secondary molded body was sintered under vacuum at 1360 ° C. for 7 hours to prepare a sintered body (punching punch of cemented carbide). This sintered body has a hardness of 1.75 GPa when measured by the method specified in CIS (Japan Machine Tool Manufacturers Association (former Carbide Tool Association) standard) 027, and CIS (Japan Machine Tool Manufacturers Association (former Carbide Tool Association) standard). Association) Standard) The density measured by the method specified in 028 is 14.7 g / cm ³ ), and the bending force measured by the method specified in CIS (Japan Machine Tool Manufacturers Association (former Carbide Tool Association) standard) 026 is It was 3.2 GPa.

Example 2
The powder molded product prepared in the same manner as in Example 1 was placed on the table shown in FIG. 1 and a wire saw (average diameter 0.25 mm) in which diamond abrasive grains were electrodeposited on a piano wire (average diameter 0.18 mm). Is moved in the X-axis direction, the powder molded body is moved forward in the Y-axis direction (+ Y-axis direction), sliced in the lateral direction, and then moved by about 0.6 mm in the Z direction (height direction) to form the powder. The operation of retreating the body in the Y-axis direction (-Y-axis direction) and slicing in the lateral direction was repeated. By such a slicing operation, a large number of plate-shaped secondary compacts having a thickness of 0.4 mm were prepared. Although the secondary molded product was thin, it could be prepared without forming damaged parts such as chips.

The obtained plate-shaped secondary molded product was sintered in the same manner as in Example 1 to prepare a sintered body (cemented carbide blade). This sintered body had the same hardness, density and bending force as in Example 1.

Example 3
In Example 1, an extra-fine round bar-shaped secondary molded body is formed in the vertical and horizontal directions in the same manner as in Example 2 except that the diameter of the round bar-shaped secondary molded body is 0.8 mmΦ in the cutting locus shown in FIG. 4 (b). It was formed adjacent to. The obtained ultrafine round bar-shaped secondary molded body was sintered in the same manner as in Example 1 to prepare a sintered body (ultrafine pin of cemented carbide). This sintered body had the same hardness, density and bending force as in Example 1.

INDUSTRIAL APPLICABILITY In the field of powder metallurgy, the present invention can produce a secondary molded product having various forms, and can also produce a sintered body obtained by sintering the secondary molded product. This sintered body can be used for applications such as magnets and cemented carbide, depending on the type of powder molded body. Cemented carbide has high hardness and strength, and cutting, drilling, cutting, rolling, drills such as abrasion resistant dies, cutting tools such as end mills, milling cutters, lathes, pinion cutters (automobile parts, engine parts, transmissions). It can be widely used for parts, metal processing of steering parts, etc.), drilling blades for shield machines, punching metal fittings, etc. In particular, a thin-walled secondary molded body can be prepared, and a columnar secondary molded body such as a round bar (including a fine round bar) can be formed. By sintering these secondary molded bodies, a cutting tool can be formed. It is possible to prepare thin-walled cemented carbide suitable for such as, and columnar cemented carbide suitable for punching punches of electronic parts.

1 ... Wire saw 10 ... Powder molded body 11 ... Table 12, 32 ... Holding member 21 ... First cutting start part 22 ... First base point 23 ... Second base point 24, 26, 28, 33, 34 ... Cutting locus 25 ... First cutting end point 17, 27, 37 ... Secondary molded body

Claims (12)

The powder compact that has not been sintered to a device for cutting a wire saw, and laterally can travel a wire saw, for this wire saw, relative to the depth direction and the height Direction A wire saw device provided with a table that is movable and on which the powder compact can be placed or held, and can cut out a plurality of secondary compacts with a continuous form of cutting locus by the wire saw. Equipment . The device according to claim 1, further comprising a cutting area in which the wire saw can travel in the lateral direction and a table in the cutting area in which the wire saw can move in the depth - height direction with respect to the wire saw. Against wire saw, a reciprocating motion means for置又mounting the table to move forward and backward a powder compact which is held in the depth direction, the upper and lower for vertically moving the powder compact in the height direction relative to a wire saw The first or second claim, wherein the moving means, the advancing / retreating means, and the vertical moving means are controlled, and a control unit for moving the powder molded body in the depth - height direction around a wire saw is provided. apparatus. The apparatus according to any one of claims 1 to 3, wherein the powder molded product has at least one property selected from the following (a), (b) and (c).
(A) Hardness 0.01 to 1 GPa
(B) Density ^{3 to 10} g / cm ³
(C) Folding force 0.1 to 50 MPa The apparatus according to any one of claims 1 to 4, wherein the powder molded product is a cemented carbide powder molded product. The powder compact that has not been sintered as the primary molded product A method for producing a secondary molded body was cut with a wire saw, it is run a wire saw laterally with respect to the wire saw, the table the placing置又the powder compact was maintained, is relatively moved in the depth direction and the height direction, to produce a plurality of secondary shaped body by cutting a powder compact at a slicing trajectory of the continuous form by a wire saw Method. The method according to claim 6, wherein the powder molded body placed or held on the table is moved to the wire saw in the depth direction and the height direction to cut out the secondary molded body having a three-dimensional three-dimensional shape. Against wire saw,置又mounting the table moves the powder molded body held in the depth direction and the height direction, cut by adjacent secondary molding of a plurality of three-dimensional shape in the depth direction according to claim 6 or the method of 7, wherein. (1) A first method of cutting a powder molded body from a first cutting start portion of the powder molded body to a predetermined first base point by moving the powder molded body forward at least in the depth direction with respect to a wire saw. Lateral cutting process and
(2) After the cut portion reaches the first base point, the powder molded body is moved forward in the depth direction and the height direction while moving forward at least in the depth direction, and at least a part of the cross-sectional outline of the secondary molded body. A three-dimensional cutting process for cutting a powder compact with a cutting locus corresponding to the outline of
(3) the first transverse cutting step and three-dimensional cutting step and one cutting cycle, the cutting cycle, while the powder molded body is advanced dynamic at least in the depth direction, repeated in the depth direction, retracts at least the depth direction by advancing, return to the first base point in a manner of single stroke, and to form a plurality of closed slicing trajectory or looped cutting trajectory, are adjacent a plurality of secondary molded body in the depth direction powder molding Repeated process for cutting the body and
(4) The method according to any one of claims 6 to 8 , which includes a step of separating and recovering the secondary molded product after the three-dimensional cutting step of the final cutting cycle. The powder molded product is cut at different height positions, and the powder molded products are cut at different height positions, and a plurality of rows of secondary molded products formed adjacent to each other in the depth direction are formed at intervals in the height direction. The method according to claim 9 , wherein the next molded body is formed. A method for producing a sintered body by sintering a secondary molded product produced by the method according to any one of claims 6 to 10 . The method according to claim 11 , wherein the sintered body is a cemented carbide.

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