Low temperature cvd coatings and applications thereof

Patent metadata

Field	Value
Publication number	US-2016215387-A1
Application number	US-201514602745-A
Country	US
Kind code	A1
Filing date	Jan 22, 2015
Priority date	Jan 22, 2015
Publication date	Jul 28, 2016
Grant date	—

Abstract

In one aspect, articles employing CVD coatings deposited at low temperatures are described herein. Briefly, a coated article described herein comprises a substrate and a refractory coating adhered to the substrate, the refractory coating including a layer of TiN deposited by thermal CVD, the layer of TiN having an average crystallite size of 0.05 μm to 0.5 μm and residual tensile stress of 100 MPa to 700 MPa.

First claim

1 . A coated article comprising:
a substrate; and a refractory coating adhered to the substrate, the refractory coating including a layer of titanium nitride deposited by thermal chemical vapor deposition (CVD), the layer of titanium nitride having an average crystallite size of 0.05 μm to 0.5 μm and residual tensile stress of 100 MPa to 700 MPa.

2 . The coated article of claim 1 , wherein the titanium nitride layer has hardness of 1500 HV to 2500 HV.

3 . The coated article of claim 1 , the titanium nitride layer has a texture coefficient greater than 3.5 for the (200) growth direction, the texture coefficient (TC) being defined as

TC


(
hkl
)

=

I


(
hkl
)

I
0



(
hkl
)



{

1
n



∑

I


(
hkl
)

I
0



(
hkl
)

}

-
1

where
I(hkl)=measured intensity of the (hkl) reflection
I 0 (hkl)=standard intensity of the (hkl) reflection according to International Center for Diffraction Data (ICDD) card 38-1420
n=number of reflections used in the TC calculation
(hkl) reflections used in the TC calculation are (111), (200), (220), (311), (222), (400), (331) and (422).

4 . The coated article of claim 3 , wherein the titanium nitride layer has a TC greater than 4.0.

5 . The coated article of claim 1 , wherein the substrate is selected from the group consisting of cemented carbide, ceramic and alloy.

6 . The coated article of claim 1 , wherein the titanium nitride layer forms an interface with the substrate.

7 . The coated article of claim 6 , wherein the substrate is cemented carbide, the cemented carbide substrate having residual tensile stress of 50 MPa to 300 MPa at a depth within 2 μm of the interface with the titanium nitride layer.

8 . The coated article of claim 7 , wherein the cemented carbide substrate has a pre-coat treated surface condition.

9 . The coated article of claim 8 , wherein the cemented carbide substrate has a blasted surface condition.

10 . The coated article of claim 5 , wherein the substrate is an alloy selected from the group consisting of steels, iron-based alloys, nickel-based alloys and cobalt-based alloys.

11 . The coated article of claim 1 , wherein the titanium nitride layer has a thickness of 1 μm to 200 μm.

12 . The coated article of claim 1 , wherein the titanium nitride layer has a thickness of 5 μm to 100 μm.

13 . The coated article of claim 1 , wherein the refractory coating further comprises one or more inner layers between the titanium nitride layer and the substrate, an inner layer comprising one or more metallic elements selected from the group consisting of aluminum and metallic elements of Groups IVB, VB and VIB of the Periodic Table and one or more non-metallic elements of Groups IIIA, VI, VA and VIA of the Periodic Table.

14 . The coated article of claim 1 , wherein the refractory coating further comprises one or more outer layers over the titanium nitride layer, an outer layer comprising one or more metallic elements selected from the group consisting of aluminum and metallic elements of Groups IVB, VB and VIB of the Periodic Table and one or more non-metallic elements of Groups IIIA, VI, VA and VIA of the Periodic Table.

15 . The coated article of claim 1 , wherein the substrate is a cutting tool.

16 . The coated article of claim 1 , wherein the substrate is a wear component.

17 . The coated article of claim 1 , wherein the layer of titanium nitride has a critical load (L c ) of at least 70 N.

18 . A method of making a coated article comprising:
providing a substrate; and depositing a refractory coating over the substrate, the refractory coating including a layer of titanium nitride having an average crystallite size of 0.05 μm to 0.5 μm and a residual tensile stress of 100 MPa to 700 MPa, wherein the titanium nitride layer is deposited by thermal CVD in a reactor from a gaseous mixture comprising a titanium source and a nitrogen source at a temperature of 350° C. to 750° C.

19 . The method of claim 18 , wherein the titanium nitride layer is deposited at a temperature of 400° C. to 650° C.

20 . The method of claim 18 , wherein the titanium source is a titanium chloride.

21 . The method of claim 20 , wherein the titanium chloride is TiCl 4 .

22 . The method of claim 18 , wherein the nitrogen source is selected from the group consisting of ammonia, secondary amine and tertiary amine.

23 . The method of claim 18 , wherein the titanium nitride layer is deposited at a rate of 0.2 μm/hr to 5 μm/hr.

24 . The method of claim 18 , wherein the titanium nitride layer has a thickness of 1 μm to 200 μm.

25 . The method of claim 18 , wherein a ratio of the nitrogen source to the titanium source ranges from 4:3 to 7:2.

26 . The method of claim 18 , wherein the titanium nitride layer has hardness of 1500 HV to 2500 HV.

27 . The method of claim 18 , wherein the titanium nitride layer has a texture coefficient greater than 3.5 for the (200) growth direction, the texture coefficient (TC) being defined as

TC


(
hkl
)

=

I


(
hkl
)

Assignees

• Kennametal Inc

Inventors

• Liu Zhenyu
• Zheng Qingjun
• Leicht Peter Rudolf
• Liu Yixiong

Classifications

• C23C16/34 Primary

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

• C04B35/58014 Primary

  based on titanium nitrides, e.g. TiAlON · CPC title

• C23C16/06 Primary

  characterised by the deposition of metallic material · CPC title

• C23C16/44

  characterised by the method of coating (C23C16/04 takes precedence) · CPC title