Hard coating, hard-coated tool, and their production methods

Patent metadata

Field	Value
Publication number	US-2019177839-A1
Application number	US-201716310586-A
Country	US
Kind code	A1
Filing date	Jun 30, 2017
Priority date	Jul 7, 2016
Publication date	Jun 13, 2019
Grant date	—

Abstract

A hard coating comprising a lower layer formed by an fcc-based titanium aluminum nitride coating, and an upper layer formed by an aluminum nitride coating having an hcp crystal system, the upper layer having a columnar crystal structure, the columnar crystals having an average transverse cross section diameter of 0.05-0.6 μm, and a ratio of an X-ray diffraction peak value Ia(002) of (002) planes to an X-ray diffraction peak value Ia(100) of (100) planes in the upper layer meeting the relation of Ia(002)/Ia(100)≥6.

First claim

1 . A hard coating comprising a lower layer formed by an fcc-based titanium aluminum nitride coating and an upper layer formed by an aluminum nitride coating having an hcp crystal system; said upper layer having an columnar crystal structure, said columnar crystals having an average transverse cross section diameter of 0.05-0.6 μm, and a ratio of an X-ray diffraction peak value Ia(002) of (002) planes to an X-ray diffraction peak value Ia(100) of (100) planes in said upper layer meeting the relation of Ia(002)/Ia(100)≥6.

2 . The hard coating according to claim 1 , wherein a ratio of a merged X-ray diffraction peak value It(111)Ia(101) of the (111) planes of said lower layer and the (101) planes of said upper layer to said Ia(100) meets the relation of It(111)Ia(101)/Ia(100)≥1.5, in an X-ray diffraction angle 2θ range of 36° to 39°.

3 . The hard coating according to claim 1 , wherein a ratio of a merged X-ray diffraction peak value It(111)Ia(101) of the (111) planes of said lower layer and the (101) planes of said upper layer to the X-ray diffraction peak value It(200) of the (200) planes of said lower layer meets the relation of It(111)Ia(101)/It(200)≥1.5, in an X-ray diffraction angle 2θ range of 36-39°.

4 . The hard coating according to claim 1 , wherein 30% or more of lattice fringes are continuous in an interface between said lower layer and said upper layer.

5 . A hard-coated tool having the hard coating recited in claim 1 formed on a substrate.

6 . A method for producing the hard coating recited in claim 1 by a chemical vapor deposition method, comprising
(1) using a mixture gas A 1 comprising a TiCl 4 gas, an AlCl 3 gas, an N 2 gas and an H 2 gas, and a mixture gas B 1 comprising an N 2 gas, an NH 3 gas and an H 2 gas, as a first starting material gas for forming said lower layer; and
(2) using a mixture gas A 2 comprising an AlCl 3 gas, an N 2 gas and an H 2 gas, and a mixture gas B 2 comprising an NH 3 gas, an N 2 gas and an H 2 gas, as a second starting material gas for forming said upper layer.

7 . The method for producing a hard coating according to claim 6 , wherein
said first starting material gas is composed of a mixture gas A 1 having a composition comprising 0.02-0.31% by volume of TiCl 4 gas, 0.15-0.8% by volume of an AlCl 3 gas, and 3-40% by volume of an N 2 gas, the balance being an H 2 gas, and a mixture gas B 1 having a composition comprising 0.4-1.9% by volume of an NH 3 gas, and 2-26% by volume of an N 2 gas, the balance being an H 2 gas, with the total amount of the TiCl 4 gas, the AlCl 3 gas, the NH 3 gas, the N 2 gas, and the H 2 gas as 100% by volume, a volume ratio H 2 (A 1 )/H 2 (B 1 ) of an H 2 gas in said mixture gas A 1 to an H 2 gas in said mixture gas B 1 being 1-5; and said second starting material gas is composed of a mixture gas A 2 having a composition comprising 0.5-1.4% by volume of an AlCl 3 gas, and 10.6-30.6% by volume of an N 2 gas, the balance being an H 2 gas, and a mixture gas B 2 having a composition comprising 0.6-0.95% by volume of an NH 3 gas, and 10.6-30.6% by volume of an N 2 gas, the balance being an H 2 gas, with the total amount of the AlCl 3 gas, the NH 3 gas, the N 2 gas and the H 2 gas as 100% by volume, a volume ratio H 2 (A 2 )/H 2 (B 2 ) of an H 2 gas in said mixture gas A 2 to an H 2 gas in said mixture gas B 2 being 0.3-3.

8 . The method for producing a hard coating according to claim 6 , wherein
a chemical vapor deposition apparatus comprising first and second pipes rotating around a rotation axis O is used; said first pipe has first nozzles; said second pipe has second nozzles; the distance H 1 between the openings of said first nozzles and said rotation axis O is larger than the distance H 2 between the openings of said second nozzles and said rotation axis O; and (a) said mixture gases A 1 , A 2 are successively ejected from said first nozzles, and said mixture gases B 1 , B 2 are successively ejected from said second nozzles, or (b) said mixture gases B 1 , B 2 are successively ejected from said first nozzles, and said mixture gases A 1 , A 2 are successively ejected from said second nozzles.

9 . (canceled)

10 . The method for producing a hard coating according to claim 8 , wherein a ratio (H 1 /H 2 ) of said distance H 1 to said distance H 2 is in a range of 1.5-3.

11 . The method for producing a hard coating according to claim 6 , wherein said lower layer is formed at a forming pressure of 3-6 kPa and a forming temperature of 750-900° C.; and said upper layer is formed at a forming pressure of 3-5 kPa and a forming temperature of 750-850° C.

12 . A method for producing the hard-coated tool recited in claim 5 , wherein
(1) a first starting material gas composed of a mixture gas A 1 comprising a TiCl 4 gas, an AlCl 3 gas, an N 2 gas and an H 2 gas, and a mixture gas B 1 comprising an N 2 gas, an NH 3 gas and an H 2 gas is introduced into a chemical vapor deposition apparatus containing substrates, to form said lower layer; and then (2) a second starting material gas composed of a mixture gas A 2 comprising an AlCl 3 gas, an N 2 gas and an H 2 gas, and a mixture gas B 2 comprising an NH 3 gas, an N 2 gas and an H 2 gas is introduced into a chemical vapor deposition apparatus containing substrates, to form said upper layer.

13 . The method for producing a hard-coated tool according to claim 12 , wherein
said first starting material gas is composed of a mixture gas A 1 having a composition comprising 0.02-0.31% by volume of a TiCl 4 gas, 0.15-0.8% by volume of an AlCl 3 gas, and 3-40% by volume of an N 2 gas, the balance being an H 2 gas, and a mixture gas B 1 having a composition comprising 0.4-1.9% by volume of an NH 3 gas, and 2-26% by volume of an N 2 gas, the balance being an H 2 gas, with the total amount of the TiCl 4 gas, the AlCl 3 gas, the NH 3 gas, the N 2 gas, and the H 2 gas as 100% by volume, a volume ratio H 2 (A 1 )/H 2 (B 1 ) of an H 2 gas in said mixture gas A 1 to an H 2 gas in said mixture gas B 1 being 1-5; and said second starting material gas is composed of a mixture gas A 2 having a composition comprising 0.5-1.4% by volume of an AlCl 3 gas, and 10.6-30.6% by volume of an N 2 gas, the balance being an H 2 gas, and a mixture gas B 2 having a composition comprising 0.6-0.95% by volume of an NH 3 gas, and 10.6-30.6% by volume of an N 2 gas, the balance being an H 2 gas, with the total amount of the AlCl 3 gas, the NH 3 gas, the N 2 gas and the H 2 gas as 100% by volume, a volume ratio H 2 (A 2 )/H 2 (B 2 ) of an H 2 gas in said mixture gas A 2 to an H 2 gas in said mixture gas B 2 being 0.3-3.

14 . The method for producing a hard-coated tool according to claim 12 , wherein
a chemical vapor deposition apparatus comprising first and second pipes rotating around a rotation axis O is used; said first pipe comprises first nozzles; said second pipe comprises second nozzles; the distance H 1 between the openings of said first nozzles and said rotation axis O is larger than the distance H 2 between the openings of said second nozzles and said rotation axis O; and (a) said mixture gases A 1 , A 2 are successively ejected from said first nozzles, and said mixture gases B 1 , B 2 are successively ejected from said second nozzles, or (b) said mixture gases B 1 , B 2 are successively ejected from said first nozzles, and said mixture gases A 1 , A 2 are successively ejected from said second nozzles.

15 . (canceled)

16 . The method for producing a hard-coated tool according to

Assignees

• Mitsubishi Hitachi Tool Eng Ltd

Inventors

• Fukunaga Yuuzoh
• Imai Masayuki

Classifications

• B23B27/148

  Composition of the cutting inserts · CPC title

• C23C16/45578

  Elongated nozzles, tubes with holes · CPC title

• B23C5/16

  characterised by physical features other than shape · CPC title

• C23C16/34 Primary

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

• B23C2224/24

  Titanium aluminium nitride (TiAlN) · CPC title