Coated cutting tool insert with MT-CVD TiCN on TiAI(C,N)

Patent metadata

Field	Value
Publication number	US-10407777-B2
Application number	US-201515514275-A
Country	US
Kind code	B2
Filing date	Sep 3, 2015
Priority date	Sep 26, 2014
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A coated cutting tool includes a substrate of cemented carbide, cermet, ceramics, steel or cubic boron nitride, a multi-layered wear resistant coating and at least two refractory coating layers deposited. The at least two refractory coating layers include a first coating layer and a second coating layer deposited on top of each other. The first coating layer is titanium aluminum nitride or carbonitride Ti1-uAluCvNw, with 0.2≤u≤1.0, 0≤v≤0.25 and 0.7≤w≤1.15 deposited by CVD. The second coating layer is titanium carbonitride TixCyN1-y, with 0.85≤x≤1.1 and 0.4≤y≤0.85, and is deposited on top of the first coating layer by MT-CVD. The second TixCyN1-y coating layer has a columnar grain morphology and the overall fiber texture of the TixCyN1-y coating layer is characterized by a texture coefficient TC (1 1 1)>2.

First claim

The invention claimed is:

1. A coated cutting comprising:
a substrate of cemented carbide, cermet, ceramics, steel or cubic boron nitride; and
a multi-layered wear resistant coating having a total coating thickness from 5 to 25 μm and including at least two refractory coating layers deposited by chemical vapour deposition (CVD) or moderate temperature chemical vapour deposition (MT-CVD), the at least two refractory coating layers including a first coating layer and a second coating layer being deposited on top of each other, wherein the first coating layer consists of titanium aluminium nitride or carbonitride Ti 1-u Al u C v N w , with 0.2≤u≤1.0, 0≤v≤0.25 and 0.7≤w≤1.15, deposited by CVD at a reaction temperature in the range from 600° C. to 900° C., the second coating layer being titanium carbonitride Ti x C y N 1-y , with 0.85≤x≤1.1 and 0.4≤y≤0.85, deposited on top of the first coating layer by MT-CVD at a reaction temperature in the range from 600° C. to 900° C., and wherein the second Ti x C y N 1-y coating layer has a columnar grain morphology, an overall fiber texture of the Ti x C y N 1-y coating layer having a texture coefficient TC (1 1 1)>2, the TC (1 1 1) being defined as:

TC
⁡

(
111
)

=

I
⁡

(
111
)

I
0

⁡

(
111
)

⁡

[

1
n

⁢

∑

n
-
1

n

⁢

I
⁡

(
hkl
)

I
0

⁡

(
hkl
)

]

-
1

,

wherein
(h k l)=measured intensity of the (hkl) reflection
I 0 (h k l)=standard intensity of the standard powder diffraction data according to
JCPDF-card no. 42-1489
n=number of reflections used in the calculation, whereby the (hkl) reflections used are: (1 1 1), (2 0 0), (2 2 0) and (3 1 1).

2. The coated cutting tool of claim 1 , wherein the second Ti x C y N 1-y coating layer has a thickness L and an average grain diameter W, and a ratio L/W<5.

3. The coated cutting tool of claim 1 , wherein the grains of the second Ti x C y N 1-y coating layer have an average grain diameter W of W≥0.4 μm.

4. The coated cutting tool of claim 1 , wherein the first Ti 1-u Al u C v N w coating layer has a columnar grain morphology and the overall fiber texture of the first Ti 1-u Al u C v N w coating layer having a maximum intensity of diffraction from the {111} crystallographic planes, as determined by X-ray diffraction (XRD) pole figure measurements or EBSD measurement, which occurs within a tilt angle from a normal to a sample substrate surface of α=±20°.

5. The coated cutting tool of claim 1 , wherein a length of Σ3-type grain boundaries in the second Ti x C y N 1-y coating layer is less than 60%, of a total length of a sum of grain boundaries of ΣN-type with N=2n+1, 1≤n≤28, (=Σ3-49-type grain boundaries), the grain boundary character distribution being measured by EBSD.

6. The coated cutting tool of claim 1 , wherein the overall fiber texture of the second Ti x C y N 1-y coating layer is has a texture coefficient TC (1 1 1)>3.0.

7. The coated cutting tool of claim 1 , wherein crystals of the first Ti 1-u Al u C v N w coating layer and crystals of the second Ti x C y N 1-y coating layer have isomorphic crystal structures or face-centered cubic (fcc) crystal structures.

8. The coated cutting tool of claim 1 , wherein the multi-layered wear resistant coating includes at least one further refractory layer between the substrate surface and the first Ti 1-u Al u C v N w coating layer, the at least one further refractory layer being selected from carbides, nitrides, carbonitrides, oxycarbonitrides and borocarbonitrides of one or more of Ti, Al, Zr, V and Hf, or combinations thereof, and being deposited by chemical vapour deposition (CVD) or moderate temperature chemical vapour deposition (MT-CVD).

9. The coated cutting tool of claim 8 , wherein the at least one further refractory layer includes a TiN layer.

10. The coated cutting tool of claim 1 , wherein the first coating layer is titanium aluminium nitride or carbonitride Ti 1-u Al u C v N w , with 0.6≤u≤1.0, 0≤v≤0.1 and 0.7≤w≤1.15.

Assignees

• Walter Ag

Inventors

• Stiens Dirk
• Manns Thorsten
• Ruppi Sakari

Classifications

• C23C16/34 Primary

  Nitrides {(C23C16/303 takes precedence)} · CPC title

• C23C16/36

  Carbonitrides · CPC title

• B23B2228/105

  with specified thickness · CPC title

• C23C28/042 Primary

  including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides · CPC title

• C23C28/044

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