JP2017042901A5

JP2017042901A5 - Method for manufacturing surface-coated cutting tool

Info

Publication number: JP2017042901A5
Application number: JP2016002713A
Authority: JP
Filing date: 2016-01-08
Publication date: 2018-04-12
Anticipated expiration: 2035-08-28

Claims

E Bei a base material and a coating formed on the substrate,
The coating has an α-Al ₂ O ₃ layer including a plurality of α-Al ₂ O ₃ crystal grains,
The α-Al ₂ O ₃ layer is located on the base material side in the thickness direction and has a thickness of 1 μm, a surface portion opposite to the base material side, and a thickness of 2 μm. And an upper layer portion having
To the cross-section obtained by cutting the α-Al ₂ O ₃ layer in a plane including the normal to the surface of the α-Al ₂ O ₃ layer, wherein the electron backscatter diffraction image analysis using a field emission scanning microscope When the crystal orientation of each crystal grain is specified and a color map based on this is created,
In the color map,
In the upper layer portion, the area occupied by the crystal grains in which the normal direction of the (001) plane is within ± 10 ° with respect to the normal direction of the surface of the α-Al ₂ O ₃ layer is 90% or more,
The lower portion (001) normal direction the α-Al ₂ O ₃ layer wherein crystal grains der area less than 50% occupied to be within ± 10 ° with respect to the normal direction of the surface of the surface Ri ,
The α-Al ₂ O ₃ layer further has a stress distribution that changes in its thickness direction,
The surface side of the α-Al ₂ O ₃ layer has a compressive residual stress,
The substrate side of the α-Al ₂ O ₃ layer has a tensile residual stress, and is a method for producing a surface-coated cutting tool ,
A method for producing a surface-coated cutting tool, comprising a step of forming the coating film by a CVD method.

A substrate and a coating formed on the substrate;
The coating has an α-Al ₂ O ₃ layer including a plurality of α-Al ₂ O ₃ crystal grains ,
The α-Al ₂ O ₃ layer is located on the base material side in the thickness direction and has a thickness of 1 μm, a surface portion opposite to the base material side, and a thickness of 2 μm. And an upper layer portion having
To the cross-section obtained by cutting the α-Al ₂ O ₃ layer in a plane including the normal to the surface of the α-Al ₂ O ₃ layer, wherein the electron backscatter diffraction image analysis using a field emission scanning microscope When the crystal orientation of each crystal grain is specified and a color map based on this is created,
In the color map,
In the upper layer portion, the area occupied by the crystal grains in which the normal direction of the (001) plane is within ± 10 ° with respect to the normal direction of the surface of the α-Al ₂ O ₃ layer is 90% or more,
In the lower layer portion, the area occupied by the crystal grains in which the normal direction of the (001) plane is within ± 10 ° with respect to the normal direction of the surface of the α-Al ₂ O ₃ layer is 50% or less,
The α-Al ₂ O ₃ layer further has a stress distribution that changes in its thickness direction,
The stress distribution is
A first region in which the absolute value of compressive residual stress continuously increases from the surface side toward the base material side;
Located in the substrate side from the first region, and toward the substrate side from the front side, turned to the tensile residual stress absolute value becomes continuously smaller in the compressive residual stress, subsequently, rolling Flip had an absolute value, and continuously larger second region of the tensile residual stress,
Wherein the first region and the second region, continuously through the midpoint of the absolute value of the compressive residual stress is largest, a manufacturing method of a front surface coated cutting tool,
A method for producing a surface-coated cutting tool, comprising a step of forming the coating film by a CVD method.

The step of forming the film by the CVD method is performed by α-Al ₂₂ O _3Three Including a layer forming step,
Α-Al ₂₂ O _3Three The layer forming step includes the first α-Al ₂₂ O _3Three Forming step and second α-Al ₂₂ O _3Three The manufacturing method of the surface covering cutting tool of Claim 1 or Claim 2 including a formation process.

The first α-Al ₂₂ O _3Three The forming step is a step of forming at least the lower layer part,
The first α-Al ₂₂ O _3Three The forming process uses AlCl as the source gas. _3Three , N ₂₂ , CO ₂₂ And H ₂₂ S and the CO ₂₂ And H ₂₂ The flow rate ratio with S is CO ₂₂ / H ₂₂ The method for manufacturing a surface-coated cutting tool according to claim 3, wherein S ≧ 2.

The first α-Al ₂₂ O _3Three The film-forming time of a formation process is a manufacturing method of the surface covering cutting tool of Claim 4 which is 5 to 30 minutes.

The second α-Al ₂₂ O _3Three The forming step is a step of forming at least the upper layer part,
The second α-Al ₂₂ O _3Three The forming process uses AlCl as the source gas. _3Three , N ₂₂ , CO ₂₂ And H ₂₂ S and the CO ₂₂ And H ₂₂ The flow rate ratio with S is 0.5 ≦ CO ₂₂ / H ₂₂ The method for producing a surface-coated cutting tool according to claim 3, wherein S ≦ 1.

The second α-Al ₂₂ O _3Three The method for producing a surface-coated cutting tool according to claim 6, wherein the film formation time in the forming step is 30 minutes or more and 500 minutes or less.

The step of forming the film by a CVD method includes a compressive residual stress applying step,
The compressive residual stress application step includes the α-Al ₂₂ O _3Three The α-Al by blasting from the surface side of the layer ₂₂ O _3Three The method for producing a surface-coated cutting tool according to any one of claims 1 to 6, which is a step of applying the compressive residual stress to a layer.