# US 2014/0193624 A1 · Cutting Insert and Method for Production Thereof

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- Number: US 2014/0193624 A1
- Document ID: US20140193624A1
- Status: Published application
- Kind: A1
- Application number: 14/240,146
- Filed: 2012-09-17
- Published: 2014-07-10
- Earliest claimed: 2011-09-16
- Assignees: Walter AG
- Applicants: Walter AG
- Inventors: Dirk Stiens; Sakari Ruppi; Thomas Fuhrmann
- Web page: https://patentgrep.com/patent/US20140193624A1

## CPC

- B23B 27/148: {Composition of the cutting inserts}
- B23C 5/20: with removable cutter bits or teeth {or cutting inserts}
- C23C 16/403: {of aluminium, magnesium or beryllium}
- C23C 16/56: After-treatment
- C23C 28/044: {coatings specially adapted for cutting tools or wear applications}
- C23C 30/005: {on hard metal substrates}
- C30B 25/00: Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- Y10T 428/24975: No layer or component greater than 5 mils thick
- B23B: TURNING; BORING (arrangements for copying or controlling B23Q)
- B23C: MILLING (broaching B23D; broach-milling in making gears B23F; arrangement for copying or controlling B23Q)
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Cutting insert made of hard metal, cermet or ceramic substrate body with multi-layer coating applied thereto by CVD methods. The coating has a total thickness of 5 to 40 μm and, starting from the substrate surface, has one or more hard material layers, an alpha aluminium oxide (α-Al2O3) layer of a layer thickness of 1 to 20 μm and optionally at least portion-wise over the α-Al2O3 layer one or more further hard material layers as decorative or wear recognition layers. The α-Al2O3 layer has a crystallographic preferential orientation characterised by a texture coefficient TC (0 0 12)≧5 for the (0 0 12) growth direction. The α-Al2O3 layer has an inherent stress in the region of 0 to +300 MPas, and the substrate within a region of 0 to 10 μm from the substrate surface has an inherent stress minimum in the region of −2000 to −400 MPas.

## Claims

### Claim 1

A cutting insert, comprising:
a hard metal, cermet or ceramic substrate body; and
a multi-layer coating which is applied thereto by means of CVD methods of a total thickness of 5 to 40 μm and which starting from a surface of the substrate body has one or more hard material layers, over the hard material layers an alpha aluminium oxide (α-Al2O3) layer of a layer thickness of 1 to 20 μm and optionally at least portion-wise over the α-Al2O3 layer one or more further hard material layers as decorative or wear recognition layers,
wherein the α-Al2O3 layer has a crystallographic preferential orientation, characterised by a texture coefficient TC (0 0 12)≧5 for the (0 0 12) growth direction with
TC

(
0
0
12
)
=
I

(
0
0
12
)
I
0

(
0
0
12
)

[
1
n

∑
n
-
1
n

I

(
hkl
)
I
0

(
hkl
)
]
-
1
,
wherein
I(hkl) are the intensities of the diffraction reflections measured by X-ray diffraction,
I0(hkl) are the standard intensities of the diffraction reflections in accordance with pdf card 42-1468,
n is the number of reflections used for the calculation, and
the following reflections are used for the calculation of TC(0 0 12):
(0 1 2), (1 0 4), (1 1 0), (1 1 3), (1 1 6), (3 0 0) and (0 0 12),
wherein the α-Al2O3 layer has an inherent stress in the region of 0 to +300 MPas, and
wherein the substrate within a region of 0 to 10 μm from the surface of the substrate body has an inherent stress minimum in the region of −2000 to −400 MPas.

### Claim 2 (depends on 1)

A cutting insert according to claim 1 wherein the production of the cutting insert includes the substrate body being subjected to a dry or wet jet blasting treatment using a granular jet blasting agent.

### Claim 3 (depends on 1)

A cutting insert according to claim 1 wherein the hard material layers arranged over the surface of the substrate body and under the α-Al2O3 layer and the hard material layers arranged at least portion-wise optionally over the α-Al2O3 layer comprise carbides, nitrides, oxides, carbonitrides, oxynitrides, oxycarbides, oxycarbonitrides, borides, boronitrides, borocarbides, borocarbonitrides, borooxynitrides, borooxocarbides or borooxocarbonitrides of the elements of groups IVa to VIIa of the periodic system and/or aluminium and/or mixed metal phases and/or phase mixtures of the afore-mentioned compounds.

### Claim 4 (depends on 1)

A cutting insert according to claim 1 wherein the hard material layers arranged over the surface of the substrate body and under the α-Al2O3 layer comprise TiN, TiCN and/or TiAlCNO, wherein the hard material layers respectively involve layer thicknesses in the region of 0.1 μm to 15 μm.

### Claim 5 (depends on 1)

A cutting insert according to claim 1 wherein the hard material layers arranged over the substrate surface and under the α-Al2O3 layer and comprising TiN, TiCN and/or TiAlCNO are together of a total layer thickness in the region of 3 μm to 16 μm.

### Claim 6 (depends on 1)

A cutting insert according to claim 1 wherein the multi-layer coating starting from the surface of the substrate body has the following layer succession: TiN—TiCN—TiAlCNO-α-Al2O3, wherein optionally a TiN layer, a TiCN layer, a TiC layer or a combination thereof are provided at least portion-wise over the α-Al2O3 layer.

### Claim 7 (depends on 1)

A cutting insert according to claim 1 wherein, within a region from the outermost surface region to a depth of 10 μm from the outermost surface of the substrate body, the substrate body has an inherent stress minimum of at least −400 MPas.

### Claim 8 (depends on 1)

A cutting insert according to claim 1 wherein the substrate body comprises hard metal containing 4 to 12% by weight of Co, Fe and/or Ni, optionally 0.5 to 10% by weight of cubic carbides of the metals of groups IVb, Vb and VIb of the periodic system, or combinations thereof, and WC as the balance.

### Claim 9 (depends on 1)

A cutting insert according to claim 1 wherein the substrate body comprises hard metal and has a surface zone which is enriched with Co binder phase in relation to a nominal overall composition of the substrate body and which is depleted of cubic carbides and which starting from the surface of the substrate body is of a thickness of 5 μm to 30 μm, wherein a content of Co in the surface zone enriched with Co binder phase is at least 1.5 times higher than in a core of the substrate and a content of cubic carbides in the surface zone enriched with Co binder phase is at most 0.5 times a content of cubic carbides in the core of the substrate.

### Claim 10 (depends on 1)

A method for production of a cutting insert according to claim 1, comprising:
applying to a substrate body of hard metal, cermet or ceramic by means of CVD methods a multi-layer coating which is of a total thickness of 5 to 40 μm and which starting from a surface of the substrate body includes one or more hard material layers, over the hard material layers an alpha aluminium oxide (α-Al2O3) layer of a layer thickness of 1 to 20 μm and optionally at least portion-wise over the α-Al2O3 layer one or more further hard material layers as decorative or wear recognition layers,
wherein deposition conditions for the α-Al2O3 layer are so selected that the α-Al2O3 layer has a crystallographic preferential orientation characterised by a texture coefficient TC (0 0 12)≧5 for the (0 0 12) growth direction with
TC

(
0
0
12
)
=
I

(
0
0
12
)
I
0

(
0
0
12
)

[
1
n

∑
n
-
1
n

I

(
hkl
)
I
0

(
hkl
)
]
-
1
,
wherein
I(hkl) are the intensities of the diffraction reflections measured by X-ray diffraction,
I0(hkl) are the standard intensities of the diffraction reflections in accordance with pdf card 42-1468,
n is the number of reflections used for the calculation, and
the following reflections are used for the calculation of TC(0 0 12):
(0 1 2), (1 0 4), (1 1 0), (1 1 3), (1 1 6), (3 0 0) and (0 0 12),
wherein after application of the multi-layer coating the substrate body is subjected to a dry or wet jet blasting treatment using a granular jet blasting agent, and
wherein the jet blasting pressure, the jet blasting duration and the jet blasting angle of the jet blasting treatment are so selected that after the jet blasting treatment the α-Al2O3 layer has an inherent stress in the region of 0 to +300 MPas, and the substrate body after the jet blasting treatment within a region of 0 to 10 μm from the surface of the substrate body has an inherent stress minimum in the region of −2000 to −400 MPas.

### Claim 11 (depends on 10)

A method for production of a cutting insert according to claim 10 wherein the blasting treatment is a dry jet blasting treatment

### Claim 12 (depends on 10)

A method for production of a cutting insert according to claim 10 wherein the jet blasting agent has a lower level of hardness than corundum (α-Al2O3).

### Claim 13 (depends on 2)

A cutting insert according to claim 2 wherein the blasting treatment is a dry jet blasting treatment

### Claim 14 (depends on 2)

A cutting insert according to claim 2 wherein the jet blasting agent has a lower level of hardness than corundum (α-Al2O3).

### Claim 15 (depends on 4)

A cutting insert according to claim 4 wherein the hard material layer is TiAlCNO arranged directly under the α-Al2O3 layer and has a layer thickness in the region of 0.1 μm to 1 μm

### Claim 16 (depends on 4)

A cutting insert according to claim 4 wherein the hard material layer is TiN or TiCN with a layer thickness in the region of 2 μm to 15 μm.

### Claim 17 (depends on 16)

A cutting insert according to claim 16 wherein the layer thickness of the hard material layer of TiN or TiCN is in the region of 3 μm to 10 μm.

### Claim 18 (depends on 5)

A cutting insert according to claim 5 wherein the hard material layers arranged over the substrate surface and under the α-Al2O3 layer and comprising TiN, TiCN and/or TiAlCNO have a total layer thickness in the region of 5 μm to 12 μm

### Claim 19 (depends on 18)

A cutting insert according to claim 18 wherein the hard material layers arranged over the substrate surface and under the α-Al2O3 layer and comprising TiN, TiCN and/or TiAlCNO have a total layer thickness in the region of 7 μm to 11 μm.

### Claim 20 (depends on 7)

A cutting insert according to claim 7 wherein the inherent stress minimum is at least −600 MPas.

### Claim 21 (depends on 20)

A cutting insert according to claim 20 wherein the inherent stress minimum is at least −800 MPas.

### Claim 22 (depends on 8)

A cutting insert according to claim 8 wherein the substrate body comprises hard metal containing 4 to 12% by weight of Co

### Claim 23 (depends on 8)

A cutting insert according to claim 8 wherein the substrate body comprises 0.5 to 10% by weight of cubic carbides of Ti, Nb, Ta or combinations thereof.