# US 2008/0187775 A1 · Alumina Coated Grade

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- Number: US 2008/0187775 A1
- Document ID: US20080187775A1
- Status: Published application
- Kind: A1
- Application number: 12/021,852
- Filed: 2008-01-29
- Published: 2008-08-07
- Earliest claimed: 2007-02-01
- Assignees: Seco Tools AB
- Inventors: Sakari Ruppi; Jenni Zackrisson; Silvia Dahlund
- Web page: https://patentgrep.com/patent/US20080187775A1

## CPC

- C23C 30/005: {on hard metal substrates}
- C23C 16/0272: {Deposition of sub-layers, e.g. to promote the adhesion of the main coating}
- C23C 16/403: {of aluminium, magnesium or beryllium}
- C23C 16/45523: {Pulsed gas flow or change of composition over time}
- Y10T 428/12576: Boride, carbide or nitride component
- Y10T 428/24975: No layer or component greater than 5 mils thick
- Y10T 428/252: Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
- Y10T 428/265: 1 mil or less
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An α-Al2O3 coated cutting tool insert combining a cemented carbide with a binder phase enriched surface zone and a textured α-Al2O3-layer is disclosed. The α-Al2O3 layer has a thickness ranging from about 2-9 μm and is composed of columnar grains having a length/width ratio from about 2-12. It is characterised by a strong (104) growth texture and by low intensity of the (012), (110) and (113) diffraction peaks. The textured α-Al2O3 is preferably deposited on an MTCVD Ti(C,N) layer having a thickness from about 2-10 μm. When the alumina layer is the uppermost layer, it may be wet-blasted to an Ra value of <about 1 μm, giving the tool a black and shiny appearance.

## Claims

### Claim 1

A cutting tool insert comprising a cemented carbide body and a coating;
wherein the cemented carbide body comprises:
WC;
about 5-9 wt-% Co; and
about 5-11 wt-% cubic carbides of at least one metal selected from the group consisting of groups IVb, Vb and VIb of the periodic table;
wherein the cemented carbide body has an S-value of about 0.79-0.9 and a coercivity of about 9-16 kA/m;
wherein at least one surface of the cemented carbide body comprises a binder phase enriched surface zone with a thickness of about 5-40 μm being essentially free from cubic carbides adjacent the coating;
wherein the coating comprises at least one α-Al2O3 layer, wherein the α-Al2O3 layer is about 2-9 μm thick and wherein the α-Al2O3 layer comprises columnar grains with a length/width ratio from about 2-12 whereby the α-Al2O3 layer has a texture coefficient TC(104)≧2.0:
the texture coefficient TC(hkil) being defined as:
TC

(
hkil
)
=
I

(
hkil
)
I
0

(
hkil
)
[
1
n

∑
n
=
1
n

I

(
hkil
)
I
0

(
hkil
)
]
-
1
where:
I(hkl) intensity of the (hkl) reflection;
Io(hkl) standard intensity according to JCPDS card no. 46-1212;
n number of reflections used in the calculation;
where the (hkil) reflections used are: (012), (104), (110), (113) and (116).

### Claim 2 (depends on 1)

A cutting tool insert of claim 1,
wherein the cemented carbide body comprises about 7.5-9.5 wt-% cubic carbides of at least one metal selected from the group consisting of groups IVb, Vb and VIb of the periodic table.

### Claim 3 (depends on 1)

A cutting tool insert of claim 1,
wherein the cemented carbide body comprises cubic carbides of at least one metal selected from the group consisting of Ti, Nb, and Ta.

### Claim 4 (depends on 1)

A cutting tool insert of claim 1,
wherein the cemented carbide body has a coercivity of about 10-15 kA/m.

### Claim 5 (depends on 1)

A cutting tool insert of claim 1,
wherein at least one surface of the cemented carbide body comprises a binder phase enriched surface zone having a thickness of about 10-30 μm.

### Claim 6 (depends on 1)

A cutting tool insert of claim 1,
wherein the α-Al2O3 layer has a texture coefficient TC(104)≧about 3.

### Claim 7 (depends on 1)

A cutting tool insert of claim 1,
wherein TC(012), TC(110) and TC(113) are all <about 1.0.

### Claim 8 (depends on 1)

A cutting tool insert of claim 1,
wherein the coating comprises a first layer adjacent the body;
wherein the first layer of the coating comprises a material selected from the group consisting of CVD Ti(C,N), CVD TiN, CVD TiC, CVD HfN, MTCVD Ti(C,N), MTCVD Ti(C,O,N), MTCVD Zr(C,N), MTCVD Zr(C,O,N), MTCVD Ti(B,C,N), MTCVD (Ti,Al)(C,O,N) and combinations thereof; and
wherein the first layer of the coating has a thickness of from about 2-10 μm.

### Claim 9 (depends on 8)

A cutting tool insert of claim 8,
wherein the first layer comprises Ti(C,N).

### Claim 10 (depends on 1)

A cutting tool of claim 1,
wherein the α-Al2O3 layer is the uppermost layer and has an Ra value <about 1.0 μm.

### Claim 11 (depends on 1)

A cutting tool of claim 1,
wherein the α-Al2O3 layer has an Ra value <about 0.7 μm.