JP2007038355A - Small-diameter member and manufacturing method of small-diameter member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain adhesion and to improve wear resistance of a small-diameter member by avoiding defect and damage of a coating hard material at an edge due to plasma generated in a formation process of the coating hard material. <P>SOLUTION: The small-diameter member is formed of a bar-like body, wherein the tip of the bar-like body is provided with the coated hard material, and the coating hard material has a blade part. The defect and damage of the coated hard material at the edge part due to plasma generated in the formation process of the coated hard material are avoided to maintain the sharp edge of the blade part. The tip of the small-diameter member is formed of the coated hard material, and the small-diameter member with the blade part is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small diameter member and a manufacturing method thereof.

  An example in which a small-diameter member is processed with a cutting edge ridge line, a blade groove, and the like on a member main body and then coated with a hard film is disclosed in Patent Document 1, and further, an example in which the film is partially removed by grinding or the like after coating. It is described in.

Japanese Patent Laid-Open No. 2004-82301 JP-A-9-11050

  The present invention avoids defects and damage of the coated hard material at the edge due to the plasma generated in the process of forming the coated hard material, maintains the sharp edge blade, and improves the wear resistance of the small diameter member. is there. In the present invention, rather than forming the coated hard material on the final shaped tool, it is more effective to form the blade portion after forming the coated hard material, and when the cutting edge ridge and the groove are provided before coating Because the hard coated material grows according to their shape, especially the uneven shape, structural defects of the hard coated material occur, and in particular, the edge causes structural defects due to the growth rate difference of the hard coated material. In many cases, when used as a tool, it causes peeling and dropping of the coated hard material.

  The small-diameter member is a small-diameter member made of a rod-shaped body, having a coated hard member at the tip of the rod-shaped body, and the coated hard member having a blade portion. By adopting the above-described configuration, it is possible to avoid the defects and damage of the coated hard material at the edge portion due to the plasma generated in the process of forming the coated hard material, and to maintain the sharp edge blade portion. And the front-end | tip part of a small diameter member is comprised from the covering hard material, and the small diameter member by which the blade part was formed by this can be provided. The rod shape in the present specification indicates a cylindrical shape including a slight taper in the axial direction, an elliptical cylindrical shape, or a polygonal column shape. Further, the coated hard material indicates a hard material formed by physical vapor deposition or chemical vapor deposition.

  The invention of the present application avoids defects and damage of the coated hard material at the edge due to the plasma generated in the process of forming the coated hard material on the small diameter member, maintains the sharp edge blade, and improves the wear resistance of the small diameter member We were able to. Moreover, the manufacturing method was able to be provided.

The form of the small diameter member of the present invention is shown in FIGS. FIG. 1 shows a small-diameter member having a coated hard material 2 at the tip of the rod-like body 1 on the small-diameter side. The rod-shaped body includes a large diameter portion 3 and a small diameter portion 4. FIG. 2 is an enlarged view of the small-diameter portion, and a coating hard material is provided at the tip of the small-diameter portion. Here, since the coated hard material at the tip portion is a hard material coated and formed by physical vapor deposition or chemical vapor deposition, high adhesion strength at the interface can be obtained. Since the small-diameter portion made of a rod-like body is machined after coating, the left side view of the small-diameter portion can take a shape as shown in FIGS. 3 to 7, for example. When the small-diameter portion is a circular shape having a cylindrical shape as shown in FIG. 3, the diameter is D, and when the small-diameter portion is an elliptic shape having an elliptical cylindrical shape as shown in FIG. If the polygon is a polygonal column as shown in FIG. At this time, in particular, the torsional rigidity of the rod-shaped body can be improved by forming the small-diameter portion of the small-diameter member of the present invention from the rod-shaped body as shown in FIGS. This is because the cross-sectional area in the direction perpendicular to the axis can be made wider than in the case of the cylindrical shape in FIG. The improvement in torsional rigidity is effective in improving the machining accuracy when, for example, a small diameter member is used as a rotary tool. As shown in FIGS. 3 to 7, the blade portion can be applied to applications such as a cutting tool and a press die depending on the shape of the blade portion after processing.
Moreover, it is preferable that A value which is a diameter of the small diameter part main body of a rod-shaped body is 600 micrometers or less. This is because the characteristics as a small diameter member such as wear resistance are sufficiently exhibited when the A value is 600 μm or less. On the other hand, when the D value is less than 5 μm, there is a possibility that the small-diameter portion at the tip of the member may be deformed or disappeared by the ion bombardment process in the plasma cleaning process in the previous process for forming the coated hard material. After forming the coated hard material on the small diameter portion, the coated hard material is subjected to machining or the like to form a blade portion having an appropriate shape. As a result, defects and damage of the coated hard material at the edge due to the plasma generated in the process of forming the coated hard material are eliminated, and a small-diameter member having a sharp edge blade with very little surface irregularities.

  The blade portion of the small diameter member in the present invention forms a cutting edge ridge line at an edge portion where the outer peripheral flank and the rake face intersect. In the small diameter member of the present invention, at least one part of the cutting edge portion is made of a coated hard material, so that the effect of improving the wear resistance is obtained on the flank surface, and the work piece is welded or adhered on the rake surface. Can be reduced. Therefore, the accuracy of the workpiece surface after processing can be improved. The method for producing a small-diameter member in the present invention comprises a step of forming a coated hard material at the tip of the small-diameter portion and a step of forming a blade portion on the coated hard material by mechanical processing means. It is a manufacturing method of a member. It does not cause defects in the coated hard material, and demonstrates the original wear resistance and heat resistance of the hard material. Furthermore, the shape of a cutting edge or the like can be formed with a sharp edge, and the processing performance can be improved.

  At least one layer of the coated hard material of the present invention is preferably a hard carbon material. When the hard coating material is a hard carbon material, the properties of the solid carbon material as a solid lubricant form a lubrication layer with the workpiece and contribute to improving the wear resistance of the member body. is there. Furthermore, it is excellent in workability at the time of processing the blade portion, and a sharp edge blade portion can be formed. The hard carbon material includes a hydrogen-containing amorphous hard carbon material, a hydrogen-free amorphous hard carbon material, a hydrogen and metal-containing amorphous hard carbon material, a hard carbon material having a SP3 bond ratio of 30% to 90%, The diamond material etc. which consist only of SP3 bond substantially are included. On the other hand, the hard carbon material may be mainly composed of a hard carbon material. That is, it may be made of the above hard carbon material and less than 30 atomic% of the whole is substituted with other elements. Examples of other elements include Si, W, Cr, Ti, Al, Mo, F, Cl, O, and S. Substitution with these elements is preferable because an effect of improving chipping resistance is obtained. Further, in order to maintain the adhesion between the hard carbon material and the rod-shaped body, an adhesion reinforcing layer such as a metal layer can be combined. Furthermore, in order to reinforce and reinforce the wear resistance, one or more nitrides and carbides selected from Ti, Cr, Al, Si, Nb, Zr, Ta, V, Mo, W, Hf, and Fe are selected. It is also possible to combine a wear-resistant layer comprising one or more solid solutions or mixtures selected from borides, oxides and sulfides. Examples include (TiSi) N, (AlCrSi) N, TiN, CrN, (CrSi) N, (AlCr) N, (TiAl) N, SiC, TaN, WC, BN, AlN, AlO, SiO, MoS, and HfN. It is done. Boron nitride or a hard coating material mainly composed of boron nitride may be used.

  The member body is preferably any one of an Fe-based alloy, Ni-based alloy, Co-based alloy, Ti-based alloy, cemented carbide, cermet, and boron nitride sintered body. By appropriately selecting the combination with the hard coating material, a balance between wear resistance and breakage resistance is suitable. For the member main body, examples of the Fe-based alloy include carbon steel, stainless steel, and high-speed steel. The Co content of the cemented carbide can be selected in the range of 3 weight percent to 20 weight percent according to various applications. The application can be applied to a rotary tool, and an excellent wear resistance effect can be exhibited by, for example, an end mill, a drill, and a reamer. Hereinafter, the present invention will be described based on examples.

  The member main body made of a rod-shaped body was made of cemented carbide having a Co content of 7% by weight and a WC average particle size of 0.3 μm to 0.6 μm. The rod-shaped body has a large diameter portion and a small diameter portion. The large diameter part with the largest diameter becomes the shank part, and the small diameter part with the smallest diameter has the blade part. In the example, the shank diameter was 4 mm. The coated hard material was coated on the small diameter portion by an arc ion plating (hereinafter referred to as AIP) method, a sputtering (hereinafter referred to as SP) method, or a chemical vapor deposition (hereinafter referred to as CVD) method. For example, when a Ti target is used in the AIP method, the surface of the small diameter portion is coated with a TiN material. Thereafter, grinding was carried out so that the diameter of the small diameter portion became a target value. FIG. 8 is a schematic diagram of Example 5 of the present invention, in which an edge portion 8 is formed as a cutting edge ridge line where the flank face 6 and the rake face 7 intersect, and a two-blade blade having a core thickness B and a blade diameter D An approximate tool shape was created for the end mill. Table 1 shows Invention Examples 1 to 35 for small diameter members. Comparative examples are also shown. In the comparative example, a cemented carbide rod-shaped body was previously ground into a two-blade end mill shape in which a cutting edge ridge and a groove were formed, and then a hard film was coated with about 1 μm.

To measure the cross-sectional area of the small-diameter member, the cross section perpendicular to the axis of the blade portion was mirror-finished and measured with a scanning electron microscope (hereinafter referred to as SEM). The measurement error is considered to be a measurement error of at least ± 2 μm, taking into account the fact that the surface is mechanically cut and mirror-finished and the measurement error due to surface irregularities is taken into account. In Table 1, AIP + SP indicates the simultaneous operation of the AIP method and the SP method. CVD indicates thermal CVD, PCVD indicates plasma CVD, and EB indicates an ion plating method using an electron beam. A cemented carbide is a cemented carbide having the above-described composition unless otherwise specified. The cutting conditions shown below were used for the cutting evaluation. The condition was that ADC12 material, which is an aluminum alloy die casting, was used as a work material. For the evaluation of the cutting life, three pieces were processed with the same sample, and the average value of the cutting length was shown as the broken life.
(Cutting conditions)
Tool: Two-flute end mill Cutting method: Side finish cutting Cutting: Axial direction, 5 μm, radial direction, 1 μm
Cutting speed: 6m / min
Feed: 1 μm / blade Cutting oil: None

As shown in Table 1, in Examples 1 to 26 of the present invention, a stable breakage life was obtained compared to Comparative Examples 27 and 28, and the effects of the present invention were confirmed. Invention Examples 1 to 16 and 19 to 26 show cases in which different types of coated hard materials are used on the same cemented carbide rod-like body.
Invention Examples 1 to 3 show the case where the hard coating material is a hard carbon material, and Invention Example 4 is a diamond material. Here, the welding phenomenon of the work material was not seen at the blade part, and the effect of the lubrication characteristics also appeared, and an excellent breakage life was obtained.
Table 1 also shows the shape of the rod-shaped cross section perpendicular to the axis. As for the shape, the effects can be confirmed by comparing the combinations of Invention Examples 5 and 6, Invention Examples 7 and 8, Invention Examples 9 and 10, and Invention Examples 25 and 26. That is, when the cross-sectional shape of the rod-shaped body in the small-diameter portion is a polygonal shape or an elliptical shape rather than a circular shape, the torsional rigidity is increased, and a better breakage life is obtained. Invention Example 16 and Invention Examples 19 to 21 show cases where the S values, which are cross-sectional areas perpendicular to the axis of the blade portion made of the coated hard material, are different. A tool with a larger S value has a longer tool life, which is a favorable result. On the other hand, in Comparative Examples 27 and 28, the coated hard material was peeled off or the blade part was damaged early, resulting in a tool breakage from abnormal wear. This is considered to be because a structural defect of the coated hard material was generated on the uneven surface or the cutting edge ridge line portion by covering the base on which the blade portion was previously formed.

FIG. 1 shows a front view of a coated small diameter member. FIG. 2 shows an enlarged view of the small diameter portion of FIG. FIG. 3 shows a left side view of the small diameter portion of FIG. FIG. 4 shows a left side view after forming the blade portion. FIG. 5 shows a left side view after forming the blade portion. FIG. 6 shows a left side view after forming the blade portion. FIG. 7 shows a left side view after forming the blade portion. FIG. 8 shows a schematic cross-sectional view of the small diameter portion of Example 5 of the present invention.

Explanation of symbols

1: Rod-shaped body 2: Covered hard material 3: Large diameter part 4: Small diameter part 5: Blade part 6: Flank 7: Rake face 8: Edge part of cutting edge ridge line A: Diameter of member body B: Core thickness D: Blade diameter S: Cross-sectional area perpendicular to the axis of the blade

Claims (4)

A small-diameter member comprising a rod-shaped body, having a coated hard material at a tip portion of the rod-shaped body, and the coated hard material having a blade portion. The small diameter member according to claim 1, wherein the blade portion has a cutting edge ridge line and a blade groove. The small diameter member according to claim 1 or 2, wherein at least one layer of the hard coating material is a hard carbon material. The method for producing a small-diameter member according to claim 1, comprising a step of forming a coated hard material at the tip of the rod-shaped body and a step of forming a blade portion on the coated hard material by a mechanical processing means. A manufacturing method of a small diameter member.

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