JP2001322005A - Surface coated cemented carbide cutting tool with excellent wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool with excellent wear resistance. SOLUTION: In the surface coated cemented carbide cutting tool made by physically depositing a tough coating layer made of one kind of single layer or two kinds of multilayers of a composite nitride layer and a composite carbonitride layer of Ti and Al by average thickness of 0.5 to 15 μm via an adhesive substrate coating layer made of one kind of single layer or two kinds of multilayers of a carbide layer, a nitride layer and a carbonitride layer of Ti having average thickness of 0.1 to 10 μm on the surface of a tool substrate made of tungsten carbide group cemented carbide or titanium carbonitride group cermet, a wear resistant coating layer made of an aluminum oxide main body layer made by substituting a part of Al by one kind or not less than two kinds of Ta, V, Nb, W, Mo and Cr of 5 to 20 atomic percent of the total amount with Al to bring a solid solution is physically deposited by average thickness of 0.5 to 15 μm on the surface of the tool in a state that a crystal structure of aluminum oxide is held via an adhesive intermediate coating layer made of one kind of single layer or two kinds of multilayers of a composite carbon oxide layer and a composite carbonitroxide layer of Ti and Al having average thickness of 0.1 to 10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool made of a surface-coated cemented carbide which has excellent wear resistance and therefore exhibits excellent cutting performance over a long period of time, for example, in continuous cutting and interrupted cutting of steel. Hereinafter, referred to as a coated carbide cutting tool).

[0002]

2. Description of the Related Art Conventionally, for example, an arc ion plating apparatus, which is a kind of physical vapor deposition apparatus schematically shown in FIG.
In the state heated to a temperature of ℃, the anode electrode and the cathode electrode (evaporation source) on which Ti is formed for forming the adhesive base coating layer and Ti-Al alloy having a predetermined composition is formed for forming the tough coating layer. In the meantime, an arc discharge is generated, and at the same time, methane gas and / or nitrogen gas are introduced into the apparatus as a reaction gas, while tungsten carbide (hereinafter referred to as WC) is used.
A tool base made of a base cemented carbide or titanium carbonitride (hereinafter, referred to as TiCN) base cermet, and disposed opposite to the anode electrode and the cathode electrode at a predetermined interval (hereinafter, these are collectively referred to as a cemented carbide base). For example, under the condition that a bias voltage of, for example, -120 V is applied, the surface of the cemented carbide tool base is coated, for example, as disclosed in
No. 6565, 0.1 to 10 μm
Single layer or two or more layers of Ti carbide layer, nitride layer, and carbonitride layer (hereinafter, referred to as TiC layer, TiN layer, and TiCN layer, respectively) having an average layer thickness of Of a composite nitride of Ti and Al [hereinafter, referred to as (Ti, Al) N] layer and a composite carbonitride [hereinafter, referred to as (Ti, Al) CN] layer through an adhesive undercoat layer made of A coated carbide cutting tool manufactured by physical vapor deposition of a tough coating layer consisting of one kind of single layer or two kinds of multiple layers with an average layer thickness of 0.5 to 15 μm is known.

[0003]

On the other hand, in recent years, FA and speed of cutting have been remarkable, and there is also a demand for labor saving and energy saving of cutting. As a result, the life of cutting tools has been extended. However, in the case of the above-mentioned conventional coated carbide cutting tool, the tough coating layer composed of the (Ti, Al) N layer and the (Ti, Al) CN layer has excellent strength and strength. Although it has toughness and shows good chipping resistance (the property that micro chipping does not easily occur on the tool cutting edge), it has insufficient wear resistance,
At present, the service life is reached in a relatively short time.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoints, studies were conducted to improve the wear resistance of the conventional coated carbide cutting tool. As a result, (a) the ordinary Al ₂ O ₃ coating layer formed by the physical vapor deposition method has a high heat resistance. It is desirable to improve wear resistance because it has excellent hardness and high hardness, but the Al ₂ O ₃ coating layer is a tough coating layer constituting the above-mentioned conventional coated carbide cutting tool. Since it has poor adhesion to certain (Ti, Al) N layers and (Ti, Al) CN layers, the surface of the conventional coated carbide cutting tool is coated with the Al ₂ O
_{3 In} coated carbide cutting tools with a coating layer formed,
In particular, when performing intermittent cutting in which a high load is applied to the tool cutting edge under heavy cutting conditions such as high depth of cut and high feed, the above Al ₂ O ₃
The coating layer is easily peeled off and cannot be put to practical use.

(B) Constituting the above-mentioned conventional coated carbide cutting tool
(Ti, Al) N layer and (Ti, Al) CN layer
First, a composite of Ti and Al
A layer of carbonate [hereinafter referred to as (Ti, Al) CO] layer and
// Compound carbonitride of Ti and Al [hereinafter, (Ti,
Al) CNO] layer was physically vapor-deposited, and
Ta, V, Nb, W, Mo and
And Cr, that is, an ionic radius of 0.57 angstroms
Ion radius is 0.68 on each
Gustroms Ta, 0.69 Angstroms N
b, 0.65 angstrom V, 0.64 on
Gustrom's Cr, 0.68 Angstrom's M
o and one of 0.68 Å of W
Or two or more kinds of Al_TwoO_ThreeAl in the crystal structure of
5 to 20 atoms in a part of the total amount with Al
%, Preferably 7 to 15 atomic%.
Al contained in solution_TwoO_ThreeWhen the main layer is physically deposited,
 The resulting Al_TwoO _ThreeWhile retaining the crystal structure of
Al_TwoO_ThreeThe main layer is a lattice with a large ion radius difference.
Due to the increase in internal strain, ordinary physical vapor-deposited Al
_TwoO_ThreeAlthough the coating layer is affected by the layer thickness, 0.2 to 0.8 G
While having a compressive residual stress of Pa,
It has a compressive residual stress.
Al with high power_TwoO_ThreeThe main layer is the (Ti, Al) CO layer
And (Ti, Al) CNO layer adheres extremely strongly,
And Al_TwoO_ThreeWhile maintaining the characteristics of
The (Ti, Al) CO layer and the (Ti, Al) CNO
The layers are the (Ti, Al) N layer and the (Ti, Al) CN
With excellent adhesion to the tough coating layer
Therefore, the TiC layer, the TiN layer, and the TiCN layer
Carbide substrate having a cohesive undercoating layer and the toughness
Carbide tools, combined with excellent adhesion to the conductive coating layer
Before being physically deposited on the substrate via the adhesive undercoat layer
The above-mentioned (Ti, Al) CO layer and the toughness coating layer are further added.
And the above-mentioned Al through a (Ti, Al) CNO layer._TwoO_Threemain
Coated carbide cutting tools made by physical vapor deposition of body layers are, for example, steel
Intermittent cutting, especially at high depth of cut with high load on tool cutting edge
Even under heavy cutting conditions such as high feed rate_TwoO_Three
Excellent wear resistance over a long period without peeling of the main layer
To be able to demonstrate their sexuality. (A) and (b)
The research results shown in the above were obtained.

The present invention has been made on the basis of the above research results, and has a surface of a cemented carbide tool substrate having a thickness of 0.1%.
The (Ti, Al) N layer and the (Ti, Al) N layer are formed through an adhesive undercoating layer composed of a single layer or two or more layers of a TiC layer, a TiN layer, and a TiCN layer having an average layer thickness of 10 μm to 10 μm. A coated carbide cutting tool obtained by physically depositing a tough coating layer consisting of one kind of single layer or two kinds of multiple layers of the (Ti, Al) CN layer with an average layer thickness of 0.5 to 15 μm. On the surface of the tough coating layer, 0.1 to 10 μm
(Ti, Al) CO layer with an average layer thickness of m
(i, Al) A part of Al is retained through the adhesive intermediate coating layer composed of one kind of single layer or two kinds of multiple layers of the CNO layer while maintaining the crystal structure of Al ₂ O _3. 5 to 20 atomic% of Ta, V, Nb, in proportion to the total amount with Al
W, formed by physical vapor deposition with an average layer thickness of 0.5~15μm one or abrasion resistant coating layer comprising a formed by replacing solid solution Al ₂ O ₃ based layer in two or more of Mo and Cr And a coated carbide cutting tool having excellent wear resistance.

In the coated carbide cutting tool of the present invention, the adhesive undercoat layer, the tough coating layer,
The reason why the average thickness of the adhesive intermediate coating layer and the wear-resistant coating layer is limited as described above will be described. (A) Adhesive undercoat layer If the average layer thickness is less than 0.1 μm, it is not possible to secure a predetermined strong adhesiveness between the above-mentioned carbide tool base and the tough coating layer. If the average layer thickness exceeds 10 μm, it causes thermoplastic deformation due to high heat generated during cutting,
Since uneven wear occurs on the cutting edge, and the wear progresses rapidly due to this, the average layer thickness is reduced to 0.1%.
〜１０10 μm. (B) Tough coating layer If the average layer thickness is less than 0.5 µm, desired excellent toughness cannot be secured, and as a result, chipping or chipping (micro chipping) is likely to occur on the cutting edge. If the layer thickness exceeds 15 μm, in combination with the layer thickness of the above-mentioned adhesive undercoat layer, thermoplastic deformation during cutting is more likely to occur,
Since the service life is shortened due to the uneven wear of the cutting edge, the average layer thickness is set to 0.5 to 15 μm.
It was decided. (C) Adhesive intermediate coating layer If the average layer thickness is less than 0.1 μm, it is not possible to secure strong adhesiveness between the above-mentioned tough coating layer and wear-resistant coating layer. When the layer thickness exceeds 10 μm,
Since the entire physical vapor deposition coating layer promotes embrittlement and is likely to cause chipping or chipping of the cutting edge, the average layer thickness is set to 0.1.
It was determined as 1 to 10 μm. (D) Abrasion-resistant coating layer If the average layer thickness is less than 0.5 μm, the desired excellent wear resistance cannot be secured, while the average layer thickness is 15 μm.
If the thickness exceeds μm, chipping and chipping of the cutting edge easily occur, so the average layer thickness is set to 0.5 to 15 μm.

[0008] Further, the substitution content ratio of Al by Ta, V, Nb, W, Mo and Cr in the wear-resistant coating layer is set to 5 to 20 at.% If the content ratio is less than 5 at. A compressive residual stress that can ensure sufficient adhesion between the wear-resistant coating layer and the adhesive intermediate coating layer cannot be formed.
This is based on the reason that if the content exceeds atomic%, the compressive residual stress becomes too large and self-destruction easily occurs. Further, a TiN layer may be formed on the abrasion-resistant coating layer, if necessary, with an average thickness of 0.1 to 2 μm, since the TiN layer has a golden color tone. In this case, the color tone is insufficiently applied when the thickness of the cutting tool is less than 0.1 μm, while the color tone is insufficiently applied up to 2 μm. An average layer thickness is sufficient.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide cutting tool of the present invention will be specifically described with reference to examples. WC powder having an average particle diameter of 1 to 3 μm,
TiC powder, ZrC powder, VC powder, TaC powder, Nb
A C powder, a Cr ₃ C ₂ powder, a TiN powder, a TaN powder, and a Co powder were prepared, and these raw material powders were blended in the composition shown in Table 1, wet-mixed in a ball mill for 72 hours, and dried. It is press-molded into a green compact at a pressure of 1.5 × 10 ⁸ Pa, and the green compact is heated in a vacuum at a temperature of 1400 ° C.
For 1 hour, and after sintering, add R:
Honing process of 0.05 and ISO standard / SPG
Carbide tool bases A1 to A8 made of a WC-based cemented carbide having a chip shape of A120408 were formed. In addition, as raw material powders, T powder having an average particle size of 0.5 to 2 μm is used.
iCN (TiC / TiN = 50/50 by mass ratio) powder,
Mo ₂ C powder, ZrC powder, NbC powder, TaC powder,
WC powder, Co powder, and Ni powder were prepared, and these raw material powders were blended in the composition shown in Table 2, wet-mixed in a ball mill for 24 hours, and dried, and then 9.8 × 10
^A green compact is press-molded at a pressure of ⁷ Pa, and the green compact is pressed in a nitrogen atmosphere of 1.3 × 10 ³ Pa at a temperature of 1540 ° C.
For 1 hour, and after sintering, add R:
Applying honing process of 0.03, ISO standard, CNM
Carbide tool bases B1 to B6 made of TiCN-based cermet having a chip shape of G120406 were formed.

[0010] Then, the carbide tool bases A1 to A8 and B1 to B6 are ultrasonically cleaned in acetone and dried, and each is charged into an arc ion plating apparatus shown in FIG. As an electrode (evaporation source), Ti is used for forming an adhesive undercoat layer, and Ti-Al alloys having various component compositions are used for forming a tough coating layer. 3 × 10 ^-3 Pa
While maintaining the vacuum, the inside of the apparatus was heated to 500 ° C. by a heater, and then an Ar gas was introduced into the apparatus to obtain an Ar atmosphere of 2.5 Pa.
A pulse bias voltage of
r gas bombarding cleaning, then introducing methane gas and / or nitrogen gas as a reaction gas
With the reaction atmosphere of Pa, the pulse bias voltage applied to the cemented carbide tool base was reduced to -200 V, and an arc discharge was generated between the cathode electrode and the anode electrode. A8 and B1
Conventionally coated cemented carbide cutting tools 1 to 22 were produced by forming an adhesive base coating layer and a tough coating layer having the target compositions and target layer thicknesses shown in Tables 3 and 4 on each surface of B6.

Next, the conventional coated carbide cutting tools 1 to 1
On the surface of each of the samples No. 22, a Ti-Al alloy having various component compositions for forming an adhesive intermediate coating layer as a cathode electrode (evaporation source) by the arc ion plating apparatus of FIG. Ta for forming the conductive coating layer,
Al- (Ta, V, Nb, W, M) containing a predetermined amount of one or more of V, Nb, W, Mo and Cr.
o, Cr) alloy, and 1.3 × 1
0 while maintaining a vacuum of ^-3 Pa, the inside of the apparatus with a heater 6
While heating to a predetermined temperature within the range of 20 to 720 ° C., the pulse bias voltage applied to the carbide substrate is set to −700.
V, and then as a reaction gas in the apparatus, while introducing methane gas and oxygen gas, or methane gas, nitrogen gas, and oxygen gas for forming the adhesive intermediate coating layer, and introducing oxygen gas for forming the wear-resistant coating layer, An arc discharge is generated between the cathode electrode and the anode electrode to form an adhesive intermediate coating layer and a wear-resistant coating layer having the target compositions and target layer thicknesses shown in Tables 5 to 7, whereby the coating of the present invention is obtained. Hard cutting tools 1 to 22 were manufactured respectively.

[0012] The T ₂ in the Al ₂ O ₃ main layer constituting the wear-resistant coating layer of the coated carbide cutting tools 1 to 22 of the present invention.
When the contents of a, V, Nb, W, Mo and Cr were quantitatively analyzed using an energy dispersive X-ray measuring apparatus,
The content was substantially the same as the target content in Table 7, and the compressive residual stress of the Al ₂ O ₃ main layer was measured using an X-ray stress measurement method. Was. Furthermore, the composition and layer thickness of each coating layer were also measured by Auger spectroscopy and an optical microscope, and the compositions and average layer thicknesses substantially the same as the target compositions and target layer thicknesses in Tables 3 to 7 (measured at five arbitrary locations) (Comparison with the average value).

Next, among the various coated carbide cutting tools obtained as a result, the coated carbide cutting tools 1 to 16 of the present invention and the conventional coated carbide cutting tools 1 to 16 are described below. Work material: JIS S45C Round bar with four longitudinal grooves at equal intervals in the longitudinal direction, Cutting speed: 280 m / min., Feed: 0.3 mm / rev., Depth of cut: 3.6 mm, Cutting time: 10 min. Intermittent high-cut cutting test, and work material: JIS SCM415 lengthwise equally spaced four longitudinally grooved round bars, cutting speed: 320 m / min., Feed: 0.48 mm / rev., Depth of cut: 1. 5mm, cutting time: 10 minutes, dry intermittent high feed cutting test of alloy steel under the following conditions:
For the coated carbide cutting tools 17 to 22 of the present invention and the conventionally coated carbide cutting tools 17 to 22, a work material: JIS SUS304, four longitudinally spaced round bars at regular intervals in the longitudinal direction, cutting speed: 320 m / min., feed: 0.3 mm / rev., depth of cut: 3.4 mm, cutting time: 10 minutes, dry intermittent high depth cutting test of stainless steel under the following conditions:
And Work material: JIS SNCM439 lengthwise round bar with four longitudinal grooves, cutting speed: 350 m / min., Feed: 0.5 mm / rev., Cutting depth: 1.5 mm, cutting time: 10 A dry intermittent high-feed cutting test was performed on the alloy steel under the following conditions, and the flank wear width of the cutting edge was measured in each cutting test. Table 8 shows the measurement results.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

[Table 5]

[0019]

[Table 6]

[0020]

[Table 7]

[0021]

[Table 8]

[0022]

According to the results shown in Tables 3 to 8, it can be seen that the present invention
The coated carbide cutting tools 1-22 each have a wear-resistant coating layer.
Constituting Al_TwoO_ThreeThe main layer has an ion radius smaller than that of Al.
One of the larger Ta, V, Nb, W, Mo and Cr
Higher compressive residual stress
Hold and form the adhesive intermediate coating layer
(Ti, Al) CO layer and (Ti, Al) CNO layer
It adheres firmly, while the adhesive intermediate coating layer
(Ti, Al) N layer and (Ti,
Al) Since it comes to adhere firmly to the CN layer,
The cemented carbide substrate of the adhesive undercoat layer and the toughness
Intermittent cutting of steel, combined with strong adhesion to the conductive coating layer
Even when cutting under high cutting conditions and high feed heavy cutting conditions
Al_TwoO _ThreeExcellent abrasion resistance with no peeling of the main layer
While conventional coated carbide cutting tools 1-22
Are caused by insufficient wear resistance of the tough coating layer
Under such severe conditions, the wear progresses rapidly.
Is evident. As mentioned above, the coated carbide cutting of the present invention
The cutting tool is made of Al that constitutes the wear-resistant coating layer._TwoO_ThreeMain layer
The excellent wear resistance and adhesion of the intermediate coating layer
Excellent adhesion, carbide substrate and adhesion undercoat
Coating layer, adhesive base coating layer and tough coating layer, and toughness
Excellent secured between coating layer and adhesive intermediate coating layer
The continuous adhesion and cutting of various steels under normal conditions
And severe cutting conditions, as well as
Intermittent cutting under high cutting and high feed conditions
Even said Al_TwoO_ThreeNo peeling of the main layer
Excellent wear resistance without chipping or chipping of the blade
With excellent cutting performance over a long period of time
And are fully satisfied with energy-saving and labor-saving cutting.
It can respond.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an arc ion plating apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C22C 29/04 C22C 29/04 Z 29/08 29/08 29/10 29/10 29/12 29/12 Z 29/16 29/16 H C23C 14/06 C23C 14/06 P 14/16 14/16 BF term (reference) 3C046 FF03 FF05 FF10 FF13 FF16 FF17 FF19 FF25 4K018 AD03 AD04 AD06 FA24 KA15 4K029 AA04 BA41 BA44 BA54 BA55 BA58 BA60 BB02 BC02 BD05 EA01

Claims (1)

[Claims] 1. A tool base comprising a tungsten carbide based cemented carbide or a titanium carbonitride based cermet,
A carbide layer of Ti having an average layer thickness of 0.1-10 μm,
Of a composite nitride layer of Ti and Al and a composite carbonitride layer through an adhesive undercoating layer composed of a single layer of the nitride layer and a single layer of the carbonitride layer or a double layer of the two types. Of a single toughening layer or a tough coating layer comprising two or more
In a surface-coated cemented carbide cutting tool formed by physical vapor deposition with an average layer thickness of １５15 μm, a composite carbonate of Ti and Al further having an average layer thickness of 0.1 to 10 μm on the surface of the tough coating layer. A, while maintaining the crystal structure of aluminum oxide, through an adhesive intermediate coating layer consisting of one kind of single layer or two kinds of multiple layers of the layer and the composite carbonitride layer.
5 to 20 atomic% in a proportion of l to the total amount with Al
A wear-resistant coating layer composed of an aluminum oxide-based layer obtained by substituting one or more of Ta, V, Nb, W, Mo and Cr with a mean thickness of 0.5 to 15 μm. Cutting tool made of cemented carbide with excellent wear resistance, characterized by physical vapor deposition.