Hard material coating with yttrium and method for its deposition

• US 6,033,768 A
• Filed: 11/03/1997
• Issued: 03/07/2000
• Est. Priority Date: 03/12/1996
• Status: Expired due to Term

• Current Assignee: IHI Hauzer Techno Coating BV (IHI Corporation)
• Original Assignee: Hauzer Industries BV (Bodycote PLC)
• Inventors: Smith, Ian, Muenz, Wolf-Dieter, Donohue, Lee Adrian, Brooks, John Stuart
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US08/945,871
• Time in Patent Office: 855 Days
• Field of Search: 428/697, 428/698, 428/699, 428/216, 428/336, 51/295, 51/307, 51/309, 204/192, 204/192.1
• US Class Current: 428/216
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Ternary hard material layers are described to which a small proportion of yttrium is added to increase the resistance to wear at elevated temperatures.

Claims

1. Hard material coatings manufactured by means of one of cathodic arc evaporation, sputtering, combination processes of sputtering/cathodic arc evaporation, sputtering/low voltage electron beam evaporation, or low voltage evaporation/cathodic arc evaporation, the hard material coatings consisting substantially of:

a hard material layer of a binary, ternary or quaternary TiAl based multicomponent hard material layer comprising nitride or carbonitride with an Al-content of 10 to 70 at %, wherein the layer contains about 0.1 to 4 at % yttrium unevenly distributed over the entire hard material layer in a growth direction of the coating.

2. A hard material coating in accordance with claim 1 wherein the hard material layer consists of a polycrystal-line fcc structure (B1-NaCl-type) with a <

200>

preferred orientation.

3. A hard material coating in accordance with claim 1 wherein the intensities of the major XRD peaks from the pattern (111), (220), (311) are smaller than that of a (200) peak intensity.

4. A hard material coating in accordance with claim 3 wherein the intensities are smaller by at least 70%.

5. A hard material coating in accordance with claim 1 wherein the full width half maximum (FWHM) of the (200) XRD peak is larger than 1°

of 2.

6. A hard material coating in accordance with claim 1 wherein the yttrium content amounts to approximately 1.5 to 2.0 at %.

7. A hard material coating in accordance with claim 1 wherein the yttrium is replaced by an alloy of yttrium and scandium that is unevenly distributed over the entire hard material layer.

8. A hard material coating in accordance with claim 7 wherein the scandium content amounts to 50 at %.

9. A hard material coating in accordance with claim 1 wherein a base layer adjacent the hard material contains substantially no yttrium.

10. A hard material coating in accordance with claim 1 wherein the coating consists of a multi-layer superlattice of TiAlN/TiN, TiAlN ZrN, TiAlN/CrN, TiAlN/MoN, TiAlN/WN with an yttrium content of 0.1 to 4 at %.

11. A hard material coating in accordance with claim 1 wherein the coating consists of a multi-layer of superlattice of TiAlN/TiN, TiAlN ZrN, TiAlN/CrN, TiAlN/MoN, TiAlN/WN, whereby the yttrium is incorporated in the TiAlN layer of the multilayer superlattice.

12. A hard material coating in accordance with claim 1 wherein 1 to 10 at % of the total metal content consists of Cr.

13. A hard material coating in accordance with claim 12 wherein 2 at % of the total metal content consists of Cr.

14. A hard material coating in accordance with claim 1 wherein additional carbon content of about 30 to 70 at % is present in the hard metal layer.

15. A hard material coating in accordance with claim 14 wherein the carbon is exclusively introduced into an outer layer zone having a thickness in a range of 0.5 to 1 μ

m.

16. A hard material coating in accordance with claim 1 wherein the coating has a thickness in a range of approximately 1.5 to 5 μ

m independent of the composition of the hard metal layer.

17. A hard metal coating in accordance with claim 1 wherein the hard metal layer on a substrate polished to Ra 0.00 μ

m has a surface roughness of less than or equal to 0.050 μ

m.

18. A hard metal coating in accordance with claim 1 wherein the hard metal coating is applied to a substrate material consisting of high-speed steel or hard metal.

27. A hard material coating in accordance with claim 1 wherein the hard metal layer consists substantially of the ternary hard material layer TiAlN with an Al content of 10 to 70 at % and wherein 0.1 to 4 at % yttrium is unevenly distributed over the TiAlN layer.

28. A hard material coating in accordance with claim 27 wherein the intensities of the major XRD peaks from the pattern (111), (220), (311) are smaller than that of a (200) peak intensity.

29. A hard material coating in accordance with claim 28 wherein the intensities are smaller by at least 70%.

19. A PVD method for coating substrates with a hard material coating, wherein the hard material coating is manufactured by means of one of cathodic arc evaporation, sputtering, combination processes of sputtering/cathodic arc evaporation, sputtering/low voltage electron beam evaporation, or low voltage evaporation/cathodic arc evaporation, the hard material coatings consisting substantially of:

a hard material layer of a binary, ternary or quaternary TiAl based multi-component hard material layer comprising nitride or carbonitride with an Al-content of 10 to 70 at %, wherein the layer contains about 0.1 to 4 at % yttrium unevenly distributed over the entire hard material layer in a growth direction of the coating,

wherein the method includes the use of multi-target deposition systems in which at least one of a plurality of cathodes does not include a yttrium containing target and the substrates to be coated are mounted on rotatable substrate fixturing systems so that the substrates are intermittently exposed to cathodes including a yttrium containing target.

20. A method on accordance with claim 19 wherein the coating is deposited into a four target combined arc/unbalanced magnetron PVD position machine including four cathodes only one of which is equipped with a yttrium containing target and the substrates to be coated are mounted on a rotatable substrate fixturing system allowing at least twofold substrate rotations.

21. A method in accordance with claim 20 wherein the four cathodes are four vertically arranged linear cathodes.

22. A method in accordance with claim 20 wherein one of the plurality of cathodes is used as a cathodic arc etching cathode and wherein three other cathodes are furnished with TiAl targets and only one of the three cathodes is equipped with a yttrium containing target.

23. A method in accordance with claim 22 wherein the cathode used as a cathodic arc etching cathode is equipped with a Cr target.

24. A method in accordance with claim 23 wherein Cr is mixed into at least one of the TiAl targets of the PVD coating machine.

25. A method in accordance with claim 24 wherein the PVD coating machine is a arc coating machine.

26. A method in accordance with claim 22 wherein a cathode behind the target containing yttrium is first switched on after deposition of a base layer on a substrate containing substantially no yttrium.

30. Hard material coatings manufactured by means of one of cathodic arc evaporation, sputtering, combination processes of sputtering/cathodic arc evaporation, sputtering/low voltage electron beam evaporation;

or low voltage evaporation/cathodic arc evaporation, the hard material coatings consisting substantially of;

a hard material layer of a binary, ternary or quaternary TiAl based multi-component hard material layer comprising nitride or carbonitride with an Al-content of 10 to 70 at %, wherein the layer contains about 0. 1 to 4 at % yttrium; and

wherein a base layer adjacent to the hard material contains substantially no yttrium.