Coated cutting tool and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9945029-B2
Application number	US-201214365655-A
Country	US
Kind code	B2
Filing date	Dec 14, 2012
Priority date	Dec 14, 2011
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A coated cutting tool includes a substrate and a surface coating, wherein the coating is a Ti(C,N,O) layer comprising at least one columnar fine-grained MTCVD Ti(C,N) layer with an average grain width of 0.05-0.4 μm and an atomic ratio of carbon to the sum of carbon and nitrogen (C/(C+N)) contained in the MTCVD Ti(C,N) layer being on average 0.50-0.65. A method for manufacturing the coated cutting tool includes depositing the MTCVD Ti(C,N) layer.

First claim

The invention claimed is:

1. A coated cutting tool comprising;
a substrate;
a surface coating disposed on the substrate, said surface coating having a Ti(C,N,O) layer including at least one columnar MTCVD Ti(C,N) layer with an average grain width of 0.05-0.2 μm, measured on a cross section with a surface normal perpendicular to a surface normal of the substrate, on a rake face of said coated cutting tool, along a straight line in a direction parallel to a surface of the substrate, at a centered position between a lowermost and an uppermost interface of said columnar MTCVD Ti(C,N) layer, an average thicknesses of said columnar MTCVD Ti(C,N) layer being 8-15 μm, wherein an atomic ratio of carbon to the sum of carbon and nitrogen (C/(C+N)) contained in said MTCVD Ti(C,N) layer is in average 0.50-0.65 measured with electron microprobe analysis at 10 positions spaced 50 μm along said straight line, the Ti(C,N,O) layer including an outermost Ti(C, O) layer; and
an Al 2 O 3 layer deposited on said Ti(C, O) layer.

2. The coated cutting tool according to claim 1 , wherein the average grain width is 0.1-0.2 μm.

3. The coated cutting tool according to claim 1 , wherein the C/(C+N) ratio is 0.56-0.60.

4. The coated cutting tool according to claim 1 , wherein said MTCVD Ti(C,N) layer has an X-ray diffraction pattern measurable by CuKα radiation, wherein texture coefficients TC(hkl)
are defined as:

TC
⁡

(
hkl
)

=

I
⁡

(
hkl
)

I
0

⁡

(
hkl
)

⁡

[

1
n

⁢

∑

n
=
1

n

⁢

I
⁡

(
hkl
)

I
0

⁡

(
hkl
)

]

-
1

wherein I(hkl) is the measured intensity of the (hkl) reflection; I0(hkl) is the standard intensity according to ICDD's PDF-card No. 42-1489; n is the number of reflections used in the calculation; (hkl) reflections used are (111),(200),(220),(311),(331),(420),(422) and (511); and a sum of TC(422) and TC(311) is >5.5.

5. The coated cutting tool according to claim 1 , wherein the Al 2 O 3 layer is an α-Al 2 O 3 layer with an average thickness of 2-6 μm.

6. The coated cutting tool according to claim 1 , wherein the Ti(C,N,O) layer further comprises a Ti(C,O) layer adjacent to the Al 2 O 3 layer.

7. The coated cutting tool according to claim 1 , wherein the columnar MTCVD Ti(C,N) layer has an X-ray diffraction pattern having a 2θ position of 123.15-123.25 degrees.

8. A method for producing a coated cutting tool using a CVD process, comprising the steps of:
providing a substrate in a vacuum chamber;
providing precursors to said vacuum chamber; and
depositing a Ti(C,N,O) layer having at least one columnar MTCVD Ti(C,N) layer on said substrate, wherein the columnar MTCVD Ti(C,N) layer is deposited at a temperature of 800-850° C., using precursors comprising at least TiCl 4 , CH 3 CN or other nitrile, and H 2 , wherein a gas flow of said CH 3 CN or other nitrile is from 0.2 up to 0.5 vol-%, a gas flow of TiCl 4 is about 2-4 vol-%, and a flow of N 2 gas is less than 10 vol-%, of a total precursors gas flow during deposition of said MTCVD Ti(C,N) layer, and with a Ti/CN ratio, based on a volume percent of TiCl 4 and CH 3 CN or other nitrile provided to the vacuum chamber, of 4-8.

9. The method according to claim 8 , wherein the Ti/CN ratio is 6-7.

10. The method according to claim 8 , wherein the precursors consist of TiCl 4 , CH 3 CN and H 2 .

11. The method according to claim 8 , further comprising the step of depositing a Ti(C,N,O) layer of TiN, MTCVD Ti(C,N), HTCVD Ti(C,N) and Ti(C,O) on the substrate.

12. The method according to claim 8 , further comprising the step of depositing an α-Al2O3 layer.

13. The method according to claim 8 , wherein the flow of N 2 gas is less than 5 vol-%, of the total precursor gas flow.

14. The method according to claim 8 , wherein the columnar MTCVD Ti(C,N) layer is deposited at a temperature of 820-850° C.

Assignees

• Sandvik Intellectual Property

Inventors

• Bjormander Carl

Classifications

• C23C30/005

  on hard metal substrates · CPC title

• C23C16/36 Primary

  Carbonitrides · CPC title

• C23C28/044

  coatings specially adapted for cutting tools or wear applications · CPC title

• Y10T407/27

  comprising tool of specific chemical composition · CPC title

• B23C5/16

  characterised by physical features other than shape · CPC title