Coating, method for coating, and coated cutting tool

Patent metadata

Field	Value
Publication number	US-12290862-B2
Application number	US-202318136081-A
Country	US
Kind code	B2
Filing date	Apr 18, 2023
Priority date	Apr 19, 2021
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

A method for coating a substrate 11 is disclosed. The method includes at least the following steps: depositing a first base layer 22 comprising a nitride of at least Al and Cr on the substrate 11 by physical vapor deposition at a gradually increasing substrate bias voltage from a first substrate bias voltage to a second substrate bias voltage; depositing a second base layer 23 comprising a nitride of at least Al and Cr on the first base layer 22 by physical vapor deposition at a constant substrate bias voltage that is greater or equal to the second substrate bias voltage; and depositing an outermost indicator layer 24 on the second base layer 23 , wherein the outermost indicator layer 24 comprises a nitride of Si and Me, wherein Me is at least one of Ti, Zr, Hf, and Cr, wherein the outermost indicator layer 24 is deposited by physical vapor deposition at a substrate bias voltage that is less than the constant substrate bias voltage applied during deposition of the second base layer 23.

First claim

The invention claimed is:

1. A method for coating a substrate, the method comprising:
depositing a first base layer comprising a nitride of at least Al and Cr on the substrate by physical vapor deposition at an increasing substrate bias voltage from a first substrate bias voltage to a second substrate bias voltage to provide increasing compressive stress in the first base layer;
depositing a second base layer comprising a nitride of at least Al and Cr on the first base layer by physical vapor deposition at a constant substrate bias voltage that is greater or equal to the second substrate bias voltage to provide a constant compressive stress; and
depositing an outermost indicator layer on the second base layer, wherein the outermost indicator layer comprises a nitride of Si and Me, wherein Me is at least one of Ti, Zr, Hf, and Cr, wherein the outermost indicator layer is deposited by physical vapor deposition at a substrate bias voltage that is less than the constant substrate bias voltage applied during deposition of the second base layer.

2. The method of claim 1 , wherein depositing the first base layer comprises depositing alternating sublayers using a first source material having a first ratio of Al: Cr and a second source material having a second ratio of Al:Cr, wherein the first ratio of Al:Cr is different than the second ratio of Al:Cr.

3. The method of claim 2 , wherein the first ratio of Al:Cr is lower than the second ratio of Al:Cr.

4. The method of claim 3 , wherein the first ratio of Al:Cr is 70:30 and the second ratio of Al:Cr is 90:10.

5. The method of claim 1 , wherein depositing the second base layer comprises depositing alternative sublayers, wherein the alternating sublayers include a first sublayer having a first ratio of Al:Cr and a second sublayer having a second ratio of Al:Cr, wherein the first ratio is different from the second ratio.

6. The method of claim 5 , wherein the first ratio of Al:Cr is lower than the second ratio of Al:Cr.

7. The method of claim 6 , wherein the first ratio of Al:Cr is 70:30 and the second ratio is 90:10.

8. The method of claim 1 , wherein the first base layer comprises at least 90 vol. % face-centered cubic crystalline phase.

9. The method of claim 1 , wherein the second base layer comprises at least 90 vol. % face-centered cubic crystalline phase.

10. The method of claim 1 , wherein the first base layer has a volume fraction of face-centered cubic crystalline phase that varies over a thickness direction to define a gradient from a first volume fraction of face-centered cubic crystalline phase at a first distance from the substrate to a second volume fraction of face-centered cubic crystalline phase at a second distance from the substrate, wherein the second volume fraction of face-centered cubic crystalline phase is greater than the first volume fraction of face-centered cubic crystalline phase.

11. The method of claim 10 , wherein the second base layer has a volume fraction of face-centered cubic crystalline phase that is substantially constant over a thickness direction, wherein the substantially constant volume fraction of face-centered cubic crystalline phase is greater than or equal to the second volume fraction of face-centered cubic crystalline phase of the first base layer.

12. The method of claim 1 , wherein the substrate has a rake face, a flank face, and a cutting edge formed at the intersection of the rake face and the flank face.

13. The method of claim 1 wherein the first base layer of AlCrN is face-centered cubic crystalline phase 111 with equal or higher intensity than a related 200 signal in an XRD Bragg Brentano scan.

14. A method for coating a substrate, the method comprising:
depositing a first base layer consisting essentially of a nitride of Al and Cr on the substrate by physical vapor deposition at an increasing substrate bias voltage from a first substrate bias voltage to a second substrate bias voltage to provide increasing compressive stress in the first base layer;
depositing a second base layer consisting essentially of a nitride of Al and Cr on the first base layer by physical vapor deposition at a constant substrate bias voltage that is greater or equal to the second substrate bias voltage to provide a constant compressive stress; and
depositing an outermost indicator layer on the second base layer, wherein the outermost indicator layer comprises a nitride of Si and Me, wherein Me is at least one of Ti, Zr, Hf, and Cr, wherein the outermost indicator layer is deposited by physical vapor deposition at a substrate bias voltage that is less than the constant substrate bias voltage applied during deposition of the second base layer.

Assignees

• Kennametal Inc

Inventors

• Kohlscheen Joern

Classifications

• C23C30/005

  on hard metal substrates · CPC title

• B23C5/16

  characterised by physical features other than shape · CPC title

• C23C28/42

  characterized by the composition of the alternating layers · CPC title

• B23B2224/08

  Aluminium nitride · CPC title

• B23B2224/36

  Titanium nitride · CPC title