TiAlCN Layers With Lamellar Structure

Patent metadata

Field	Value
Publication number	US-2016333473-A1
Application number	US-201515112899-A
Country	US
Kind code	A1
Filing date	Mar 3, 2015
Priority date	Mar 11, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

A tool has a main part of hard metal, cermet, ceramic, steel, high-speed steel, and a single or multilayer wear protection coating applied onto the main part by CVD and which has a thickness from 3 μm to 25 μm. The wear protection coating has at least one Ti 1-x Al x C y N z layer with stoichiometric coefficients 0.70≦x<1.0≦y<0.25 and 0.75≦z<1.15 and a thickness from 1.5 μm to 17 μm. The T 1-x Al x C y N z layer has a lamellar structure with lamellae with thickness of no more than 150 nm, preferably no more than 100 nm, particularly preferably no more than 50 nm. Lamellae are made of periodically alternating regions of the Ti 1-x Al x C y N z layer with alternatingly different stoichiometric proportions of Ti and Al, having the same crystal structure (crystallographic phase), and the Ti 1-x Al x C y N z layer has at least 90% vol. % of face centered cubic (fcc) crystal structure.

First claim

1 . A tool comprising a base body of carbide, cermet, ceramic, steel or high speed steel, and a single-layer or multi-layer wear-protection coating applied thereto in a CVD process and of a thickness in the range of 3 μm to 25 μm,
wherein the wear-protection coating has at least one Ti 1-x Al x C y N z layer having stoichiometry coefficients 0.70≦x<1, 0≦y<0.25 and 0.75≦z<1.15, and with a thickness in the range of 1.5 μm to 17 μm,
wherein the Ti 1-x Al x C y N z layer has a lamellar structure with lamellae of a thickness of not more than 150 nm, wherein
wherein the lamellae are formed from periodically alternating regions of the Ti 1-x Al x C y N z layer with alternately different stoichiometric proportions of Ti and Al, having the same crystal structure (crystallographic phase), and
wherein the Ti 1-x Al x C y N z layer has at least 90 vol-% of face-centred cubic (fcc) crystal structure.

2 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has at least 95 vol-% of face-centred cubic (fcc) crystal structure.

3 . A tool according to claim 1 , wherein in the Ti 1-x Al x C y N z layer with lamellae comprising periodically alternating regions with alternately different stoichiometric proportions of Ti and Al regions with other Ti and Al proportions which respectively adjoin below and above a region of the lamellae in the layer growth direction have the same crystallographic orientation.

4 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has a columnar microstructure,
wherein the columnar crystallites have a mean length which is at least 0.35 times the thickness of the Ti 1-x Al x C y N z layer, and/or wherein the columnar crystallites have a ratio of the mean length to the mean width, measured at 50% of the thickness of the Ti 1-x Al x C y N z layer, of at least 2.5.

5 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has a preferential orientation of crystal growth with respect to a crystallographic {hkl} plane, characterised by a texture coefficient TC (hkl) >1.5,
wherein the texture coefficient TC (hkl) is defined as follows:

TC


(
hkl
)

=

I


(
hkl
)

I
0



(
hkl
)



[

1
n



∑

n
=
1

n





I


(
hkl
)

I
0



(
hkl
)

]

-
1

.

wherein
I(hkl) are the intensities of the diffraction reflexes, measured by X-ray diffraction,
I 0 (hkl) are the standard intensities of the diffraction reflexes in accordance with PDF chart 00-046-1200,
n is the number of reflexes used for the calculation, and
the reflexes (111), (200), (220) and (311) are used for the calculation of TC(hkl), and

wherein the preferential orientation of the crystal growth of the Ti 1-x Al x C y N z layer is present with respect to the crystallographic {111}-, {200}-, {220}- or {311}-plane.

6 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has a preferential orientation of crystal growth with respect to a crystallographic {hkl}-plane, which is characterised in that the maximum of the X-ray diffraction peak of the crystallographic {hkl}-plane, measured by X-ray diffraction diffractometry (XRD) and/or by electron backscatter diffraction (EBSD), is measured within an angle α=±20 degrees relative to the perpendicular to the surface of the base body,
wherein the preferential orientation of the crystal growth of the Ti 1-x Al x C y N z layer is present with respect to the crystallographic {111}-, {200}-, {220}- or {311}-plane.

7 . A tool according to claim 1 , wherein the full width at half maximum (FWHM) of at least one of the X-ray diffraction peaks of the crystallographic {111}-, {200}-, {220}- and {311}-planes is <1° 2θ.

8 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has a preferential orientation of crystal growth with respect to the crystallographic {111}-plane, which is characterised by a ratio of the intensities of the X-ray diffraction peaks of the crystallographic {111}-plane and the {200}-plane, I{111} and {200}, in which I{111}/I{200}>1+h(ln h) 2 , wherein h is the thickness of Ti 1-x Al x C y N z layer in “μm”.

9 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has stoichiometry coefficients 0.70≦x<1, y=0 and 0.95≦z<1.15.

10 . A tool according to claim 1 , wherein the Ti 1-x Al x C y N z layer has a Vickers hardness (HV) >2300 HV.

11 . A tool according to claim 1 , further comprising, arranged between the base body and the Ti 1-x Al x C y N z layer, at least one further carbide layer of a thickness of 0.05 μm to 7 μm, selected from a TiN layer, a TiCN layer deposited by means of high temperature CVD (CVD) or medium temperature CVD (MT-CVD), an Al 2 O 3 layer and combinations thereof and/or arranged over the Ti 1-x Al x C y N z layer is at least one further carbide layer, preferably at least one Al 2 O 3 layer of the modification γ-Al 2 O 3 , κ-Al 2 O 3 or α-Al 2 O 3 , particularly preferably an α-Al 2 O 3 layer, wherein the Al 2 O 3 layer is deposited by means of high temperature CVD (CVD) or medium temperature CVD (MT-CVD).

12 . A process for the production of a tool according to claim 1 , wherein, for producing the Ti 1

Assignees

• Walter Ag

Inventors

• Stiens Dirk
• Manns Thorsten
• Ruppi Sakari

Classifications

• C23C16/36 Primary

  Carbonitrides · CPC title

• C23C16/403

  of aluminium, magnesium or beryllium · CPC title

• B23B2222/16

  Cermet · CPC title

• C23C16/34 Primary

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

• B23B2226/18

  Ceramic · CPC title