JPH08132310A - Lubricating head film-coated drill - Google Patents

Abstract

PURPOSE: To improve adhesion resistance or fusion resistance of a drill comprising base material of tool steel, high speed steel, hard metal, or hard alloy including cermet. CONSTITUTION: A drill has a land width/groove width ratio within a range of 1.2-2.0, and a part or the whole of an effective length of the drill including a cutting blade part of the drill is coated with a hard coating comprising CrNx (satisfying an atomic ratio of 0.3<=x<=1.0) of 0.05μm-5.0μm. The outermost layer of the hard coating is coated with a hard surface coating composed of CrOy (satisfying an atomic ratio of 3<=y<=1.5) in a film thickness of 0.01μm-2.0μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill having a base material of a tool steel, a high speed steel, or a cemented carbide or a hard alloy including cermet, which has improved lubricity and adhesion resistance or welding resistance. A hard film coated drill.

[0002]

2. Description of the Related Art With respect to a drill having a hard coating film, the technology has been rapidly developed due to the generalization of PVD in recent years. At present, a high-speed drill having a TiN coating showing a golden color is started. It is applied to a drill made of high speed steel or cemented carbide coated with TiCN or the like. These are mainly developed with emphasis on wear resistance and heat resistance in cutting, but there are also work materials in a category that are completely ineffective with cutting tools for special purposes. Among these, there are soft materials such as aluminum and copper, and for these, cemented carbide and the like have been mainly used conventionally. CrN is not used in cutting tools, but is used in various parts and dies, and is said to have high corrosion resistance. Metal Press Industry Press 199
Magazine "Metal Press," published June 1, 1993, June 1993
Monthly issue, pages 33-38, or "Metal Press," 199
The various applications of CrN coating are described on pages 11 to 15 of the June 1992 issue, but there is little description of their characteristics and the like. "Metal press" that there is no application to cutting tools 1
As shown in Table 1 on page 12 of the June 994 issue, a large friction coefficient is considered to be the main factor. These conventional techniques mainly show various applications of CrN coating focusing on the hardness and expansion coefficient of the film and are essentially different from the products of the present invention.

[0003]

Generally, the cutting phenomenon is accompanied by a peculiar phenomenon such as adhesion or welding in addition to the basic ones related to wear and heat such as wear resistance and heat resistance of the tool material. As for the cutting phenomenon, the force received by the tool edge is accompanied by friction, and this friction phenomenon plays an important role in the process of cutting the work material or forming chips. Although the required functions of the cutting tool are different between pure copper and aluminum in the behavior thereof, the performance of the tool is significantly limited in the friction phenomenon for the same reason. In the case of aluminum, it is relatively easy to adhere or weld, and the adherent or weld is likely to grow. On the other hand, pure copper does not show much adhesion or welding overall, but there is a problem that there is growth of adhesion or welding at the tip of the cutting edge, causing hardness increase in the work material in the plastic flow state that has adhered or welded. there were.
In the cutting phenomenon, such a phenomenon occurs under relatively low cutting conditions as welding wear or adhesive wear occurs, but in a tool such as a drill in which the cutting speed of the cutting edge portion starts from 0 Although there is a problem, it has been an unavoidable problem with conventional tool materials or surface material types in order to raise the tool to higher performance. An object of the present invention is to provide a lubricating hard film-coated drill with improved adhesion resistance or welding resistance of a drill having a tool steel, a high speed steel and a hard alloy containing cemented carbide or cermet as a base material. To provide.

[0004]

Therefore, the present invention is directed to a drill made of tool steel, high speed steel, or hard alloy containing cemented carbide or cermet as a base material. The ratio is in the range of 1.2 to 2.0, and the CrNx of 0.05 μm to 5.0 μm (atomic ratio of 0.3 in the entire range of the effective drill length including the cutting edge portion of the drill).
≦ x ≦ 1.0, 0.3 ≦ y ≦ 1.5), and CrOy (atomic ratio 0.3 ≦ y ≦ 1.5 in the outermost layer of the hard coating). And a hard surface coating having a film thickness of 0.01 μm to 2.0 μm is formed, and the base material has a hardness of 1300 HV to 2200 HV on a Micro Vickers hardness meter of 50 g, and When the hard surface coating film is pressed with an A-scale Rockwell hardness tester, 100 indentations are produced.
As a result of observing at a magnification of 2 times, peeling is not recognized between the film and the drill base metal within the range of 1 mm or more of the outer circumference of the indentation,
The problems of the prior art described above have been solved by providing a lubricating hard film coated drill characterized by the above.

As a method for depositing CrOy on CrNx, the PVD method uses ion plating, sputter ion plating, and vacuum deposition. CrOy can be obtained by stopping N during ion plating or sputter ion plating of CrNx and introducing oxygen continuously or intermittently. In addition to this method, ion plating or other method such as PVD is used to form CrNx (satisfying 0.3 ≦ x ≦ 1.0 in atomic ratio), or Cr is vapor-deposited after formation to form an oxidizing atmosphere. It is also possible to form CrOy (having an atomic ratio of 0.3 ≦ x ≦ 1.5) by a method of heating reaction in the inside or by using anodization. Since such a hard coating needs adhesion, CrNx is arranged as the lower layer. CrNx, which is the lower layer, is more brittle than ion-plated TiN, and in actual fact, in cutting steel, its performance is generally lower than that of TiN coating. The film thickness of the CrNx hard coating is limited to 0.05 μm to 5.0 μm. The film thickness exceeding 5.0 μm may cause the sharpness of the cutting edge to be lost and affect the surface roughness. This is because the effect cannot be expected if the thickness is less than 05 μm. Atomic ratio 0.3 ≦ x ≦
The reason why 1.0 is satisfied is that the hardness of the hard coating is set to 1400 HV or more.

Regarding the coating of chromium oxide CrOy, which is the outermost layer of the CrNx hard coating, the lubricity of the powder is known, but there has been no example of the coating so far, and the characteristics are extremely brittle. . A powder different from the coating is often used as a wrap powder. In the case of coating with powder, the particles fall off immediately, so improvement in performance cannot be expected. On the other hand, in the drill cutting of copper or aluminum, the cutting resistance rise is mainly due to the condition of chip discharge, so the ratio of land width / groove width was limited to the range of 1.2 to 2.0. If this ratio is less than 1.2, chip clogging is likely to occur, and if it exceeds 2.0, the resistance of the soft material increases and the rigidity of the drill body becomes insufficient, which may affect the machining accuracy. . In addition, CrOy (atomic ratio 0.3
Satisfying ≦ x ≦ 1.5) is 0.01
The reason why the thickness is limited to the range of μm to 2.0 μm is that a film thickness exceeding 2.0 μm causes a sharp increase in cutting resistance and peeling of the coating film, and if the thickness is less than 0.05 μm, the effect cannot be expected. With CrOy, the atomic ratio is 0.3 ≦ x ≦
The reason for limiting to 1.5 is that this range is a proper range for preventing the adhesion or welding of the base material and the work material, and if less than 0.3, there is no effect, and if it exceeds 1.5, it becomes large. Because you can't.

[0007]

When copper or aluminum drill cutting limits the tool performance due to the phenomenon of adhesion or welding as described above, it is important to coat the tool surface with a material that is difficult to adhere or weld. Becomes Therefore, the applicant conducted a research study on various materials and formed an oxide of Cr in the uppermost layer, so that the friction coefficient was reduced. This phenomenon is simply due to the effect of slipping and removing the adhered material and the welded material before the growth of the adhered material and the welded material as an action of lowering the friction coefficient. In order to produce such an action, C, which has a relatively strong adhesive force,
It is necessary to form an oxide of r, and CrNx is preferably formed in the case of PVD in order to obtain a certain degree of adhesion. The action of the drill having a coating film formed by depositing CrOy on CrNx is to extremely improve the finished surface roughness, and the main action is to prevent adhesion or welding due to self-lubrication. Cutting performance has been dramatically increased. FIG. 1 shows the state of each Rockwell indentation (× 100) of the product of the present invention and the prototype in which CrOy is formed on CrNx, which has a weaker adhesive force.
Times). 2. The lubricating hard film coated drill according to claim 1, wherein the base material is optionally coated with TiN, TiC or TiCN, and the hard coating film is provided on the uppermost layer thereof. The effect of can be raised.

[0008]

【Example】

[Example 1] The land width / groove width ratio of the drill was 1.3.
Then, with a micro Vickers hardness tester whose base material has a hardness of 50 g, 1
A high-speed steel φ6 drill with 400 HV, and CrOy on CrNx by ion plating for 2.3 each.
Films of μm and 0.3 μm were formed, and pure copper was cut using an emulsion. CrNx is x in the composition of the formed film.
= 0.7, CrOy had an average composition of y = 1.2.
Cutting conditions are: cutting speed: 50m / min, feed rate: 0.25mm /
r, Work material: Pure copper thickness 25m, Through cutting. The number of processing with surface roughness Rmax = 5 μm obtained by cutting is 2.5 times or more that of a non-processed drill under the same cutting conditions, CrNx is x = 0.7, and the thickness of CrN is 2.3 μm. Even when compared with the coating, a performance of 1.5 times or more was obtained. The results are shown in FIG.

[Embodiment 2] A high speed steel φ6 drill having a ratio of land width / groove width of 1.8 and a base material of 1400 HV in a micro Vickers hardness tester having a hardness of 50 g is ion plated. CrOy was deposited on CrNx by 1.5 μm and 0.5 μm, respectively, and aluminum 6063 was cut using an emulsion. The coating component is Cr
The average composition was such that Nx was x = 0.65 and CrOy was y = 1.0. Cutting conditions are: cutting speed: 150m / min, feed rate: 0.15mm / rev, work material: aluminum 6063, thickness 15mm,
Through cutting Surface roughness due to cutting is Rmax = 1
Under the same cutting conditions, the number of machining of 0 μm is 3.5 times or more that of the untreated drill, and CrNx is x = 0.6.
5. Even when compared with the CrN coating having the film thickness of 1.5 μm, the performance of 1.4 times or more was obtained. The results are shown in FIG.

[Embodiment 3] A φ4.3 drill made of cemented carbide having a land width / groove width ratio of 1.6 and a base metal having a hardness of 50 g and a micro Vickers hardness meter of 2000 HV was ion-precoated. -CrOy on CrNx by tinging
Was formed into a film having a thickness of 3.5 μm and a film having a thickness of 0.3 μm, and aluminum 5052 was cut using oil mist lubrication. The components of the coating had an average composition of x = 0.8 for CrNx and y = 1.4 for CrOy. Cutting conditions are: cutting speed: 150m / min, feed rate: 0.15mm / rev, work material: aluminum 5052, thickness 10mm,
Through cutting Surface roughness due to cutting is Rmax = 3
Under the same cutting conditions, the number of processing of μm is 2.0 times or more that of unprocessed drill, and the thickness of TiN is 3.5 μm.
The performance was 2.9 times higher than that of the coated drill.
The results are shown in FIG.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing respective Rockwell indentations (× 100 times) in the case of a product of the present invention and a prototype in which CrOy is deposited on CrNx having a weaker adhesive force.

[Fig. 2] The ratio of land width / groove width of the drill is 1.3, and the base material is 1400 using a Micro Vickers hardness tester with a hardness of 50 g.
In a HV high-speed steel φ6 drill, CrOy films of 2.3 μm and 0.3 μm were formed on CrNx by ion plating, respectively, and pure copper was cut using an emulsion. 3.5 μm thick TiN coated drill and untreated drill Aluminum using untreated drill
A graph showing the number of holes drilled for each of the 5052 cuts.

[Fig. 3] A land width / groove width ratio of the drill is 1.8, and the base material is 1400 using a Micro Vickers hardness tester with a hardness of 50 g.
On a HV high-speed steel φ6 drill, deposit CrOy on CrNx by 1.5 μm and 0.5 μm, respectively, by ion plating, and use an emulsion to produce aluminum.
The graph showing the number of holes drilled in each of which the cutting of 063 was performed, and similarly, the unprocessed drill and the CrN-coated drill having a film thickness of 1.5 μm were used to cut aluminum.

[Fig. 4] A land width / groove width ratio of the drill is 1.8, and the base material is 1400 using a Micro Vickers hardness tester with a hardness of 50 g.
Using a high speed steel φ6 drill, which is an HV, deposit CrOy on CrNx by 3.5 μm and 0.3 μm respectively by ion plating, and use an emulsion to make aluminum.
052 was cut, and in the same way as this, a T film with a film thickness of 3.5 μm
Aluminum 5052 using iN coated drill and untreated drill
A graph showing the number of holes drilled for each.

Claims (2)

[Claims] 1. A drill comprising a tool steel, a high speed steel, or a cemented carbide or a hard alloy including cermet as a base material, wherein a land width / groove width ratio of the drill is 1.2 to 2.0. Within a range of 0.05 to 5.0 μm of CrNx (satisfying 0.3 ≦ x ≦ 1.0 in atomic ratio) within a part or the entire effective drill length including the cutting edge of the drill. The hard coating is made of CrOy (atomic ratio 0.3 ≦ y
≦ 1.5) and its film thickness is 0.01μ
m-2.0 μm hard surface coating, the base material has a hardness of 1300 HV to 2200 HV with a micro Vickers hardness meter of 50 g, and the hard surface coating film has A-scale Rockwell hardness. The result of observing the indentation generated when pressing with a meter at a magnification of 100 times is that no peeling is observed between the film and the drill base material in the range of 1 mm or more of the outer circumference of the indentation. Lubrication hard film coated drill. 2. The base material is TiN, TiC or TiCN.
2. The lubricated hard film coated drill according to claim 1, wherein said hard coated film is applied to the uppermost layer of said coated film including said hard coated film.