A solid lubricating composite coating on the surface of a substrate and its preparation method

Abstract

The invention provides a solid lubrication composite coating on the surface of a base body. The composite coating is composed of hard phase nanocrystalline CrC and a lubricating phase a-C, a CrC / a-C composite coating is formed, the characteristics that the CrC hard coating is high in hardness and low in abrasion are kept, and meanwhile the excellent self-lubricating property of the a-C material is achieved. The multi-arc ion plating technology is adopted, metal Cr serves as a target material, high-purity Ar serves as working gas, C2H2 serves as reaction gas, the CrC / a-C composite coating is deposited on the surface of the base body, and the content of the CrC phase and the a-C phase in the composite coating can be regulated and controlled by controlling the flow of the Cr target current and the reaction gas C2H2. The hardness of the composite coating reaches up to 31 GPa, the abrasion rate reaches the magnitude of 10<-16> m<3> / N.m, the friction coefficient in the atmospheric environment is lower than 0.2, the base body working in the high-abrasion and high-friction environment can be well protected, and very high application value is achieved.

Description

technical field

[0001] The method belongs to the technical field of substrate surface treatment, and in particular relates to a solid lubricating composite coating on the substrate surface and a preparation method thereof. Background technique

[0002] Chromium carbide has excellent properties such as high hardness, high melting point, high elastic modulus, chemical corrosion resistance and wear resistance, and is a widely used metal carbide. Chromium carbides usually include orthorhombic Cr 3 C 2 (Pnma), Orthogonal Cr 7 C 3 (Pnma) and cubic Cr 23 C 6 (Fm-3m) Three stable crystal forms. Due to their excellent protective properties and a thermal expansion coefficient very close to steel, they are often used as surface coatings and play an important role in the fields of knives, moulds, blades, etc.

[0003] Common methods for depositing chromium carbide coatings on the substrate surface include thermal spraying, laser cladding, physical vapor deposition, chemical vapor...

Examples

Embodiment 1

[0053] In this embodiment, the substrate is a titanium alloy ball valve, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating. The preparation method of this composite coating is specifically as follows:

[0054] (1) Pre-plating treatment

[0055] Put the substrate in petroleum ether, and use ultrasonic stirring to clean it for 15 minutes. After removing the oil on the surface of the substrate, put it into acetone and ultrasonically clean it for 15 minutes, then ultrasonically clean it in absolute ethanol for 15 minutes, and finally take it out and dry it with nitrogen;

[0056] (2) Bias reverse sputter cleaning

[0057] Put the substrate treated in step (1) into the multi-arc ion plating chamber, the temperature of the chamber is 350°C, and the back vacuum is pre-evacuated to 4.00×10 -3 Pa; then, pass Ar gas with a purity greater than or equal to 99.999% into the cavity, the Ar gas flow...

Embodiment 2

[0068] In this embodiment, the substrate is exactly the same as that in Embodiment 1. Same as Embodiment 1, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating.

[0069] The preparation method of this composite coating is specifically as follows:

[0070] (1) is identical with the step (1) in embodiment 1;

[0071] (2) same as step (2) in embodiment 1;

[0072] (3) same as step (3) in embodiment 1;

[0073] (4) Deposition of CrC / a-C composite coating

[0074] Keep the Ar gas flow constant, and then pass C with a purity greater than or equal to 99.9% into the cavity 2 h 2 As a reaction gas, the flow rate is 100sccm, and the vacuum degree is maintained at 1.20Pa; the Cr target current is increased to 65A, the deposition temperature is maintained at 400°C, and a -150V bias is applied to the substrate to deposit a CrC / a-C composite coating on the surface of the substrate. Time 120min. ...

Embodiment 3

[0081] In this embodiment, the substrate is exactly the same as that in Embodiment 1. Same as Embodiment 1, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating.

[0082] The preparation method of this composite coating is specifically as follows:

[0083] (1) is identical with the step (1) in embodiment 1;

[0084] (2) same as step (2) in embodiment 1;

[0085] (3) same as step (3) in embodiment 1;

[0086] (4) Deposition of CrC / a-C composite coating

[0087] Keep the Ar gas flow constant, and then pass C with a purity greater than or equal to 99.9% into the cavity 2 h 2 As a reaction gas, the flow rate is 150sccm, and the vacuum degree is maintained at 1.40Pa; the Cr target current is increased to 65A, the deposition temperature is maintained at 400°C, and a -150V bias is applied to the substrate to deposit a CrC / a-C composite coating on the surface of the substrate. Time 120min. ...

technical field

[0001] The method belongs to the technical field of substrate surface treatment, and in particular relates to a solid lubricating composite coating on the substrate surface and a preparation method thereof. Background technique

[0002] Chromium carbide has excellent properties such as high hardness, high melting point, high elastic modulus, chemical corrosion resistance and wear resistance, and is a widely used metal carbide. Chromium carbides usually include orthorhombic Cr 3 C 2 (Pnma), Orthogonal Cr 7 C 3 (Pnma) and cubic Cr 23 C 6 (Fm-3m) Three stable crystal forms. Due to their excellent protective properties and a thermal expansion coefficient very close to steel, they are often used as surface coatings and play an important role in the fields of knives, moulds, blades, etc.

[0003] Common methods for depositing chromium carbide coatings on the substrate surface include thermal spraying, laser cladding, physical vapor deposition, chemical vapor...

Examples

Embodiment 1

[0053] In this embodiment, the substrate is a titanium alloy ball valve, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating. The preparation method of this composite coating is specifically as follows:

[0054] (1) Pre-plating treatment

[0055] Put the substrate in petroleum ether, and use ultrasonic stirring to clean it for 15 minutes. After removing the oil on the surface of the substrate, put it into acetone and ultrasonically clean it for 15 minutes, then ultrasonically clean it in absolute ethanol for 15 minutes, and finally take it out and dry it with nitrogen;

[0056] (2) Bias reverse sputter cleaning

[0057] Put the substrate treated in step (1) into the multi-arc ion plating chamber, the temperature of the chamber is 350°C, and the back vacuum is pre-evacuated to 4.00×10 -3 Pa; then, pass Ar gas with a purity greater than or equal to 99.999% into the cavity, the Ar gas flow...

Embodiment 2

[0068] In this embodiment, the substrate is exactly the same as that in Embodiment 1. Same as Embodiment 1, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating.

[0069] The preparation method of this composite coating is specifically as follows:

[0070] (1) is identical with the step (1) in embodiment 1;

[0071] (2) same as step (2) in embodiment 1;

[0072] (3) same as step (3) in embodiment 1;

[0073] (4) Deposition of CrC / a-C composite coating

[0074] Keep the Ar gas flow constant, and then pass C with a purity greater than or equal to 99.9% into the cavity 2 h 2 As a reaction gas, the flow rate is 100sccm, and the vacuum degree is maintained at 1.20Pa; the Cr target current is increased to 65A, the deposition temperature is maintained at 400°C, and a -150V bias is applied to the substrate to deposit a CrC / a-C composite coating on the surface of the substrate. Time 120min. ...

Embodiment 3

[0081] In this embodiment, the substrate is exactly the same as that in Embodiment 1. Same as Embodiment 1, the hard sealing surface of the substrate is a Cr transition layer, and the surface of the Cr transition layer is a CrC / a-C composite coating.

[0082] The preparation method of this composite coating is specifically as follows:

[0083] (1) is identical with the step (1) in embodiment 1;

[0084] (2) same as step (2) in embodiment 1;

[0085] (3) same as step (3) in embodiment 1;

[0086] (4) Deposition of CrC / a-C composite coating

[0087] Keep the Ar gas flow constant, and then pass C with a purity greater than or equal to 99.9% into the cavity 2 h 2 As a reaction gas, the flow rate is 150sccm, and the vacuum degree is maintained at 1.40Pa; the Cr target current is increased to 65A, the deposition temperature is maintained at 400°C, and a -150V bias is applied to the substrate to deposit a CrC / a-C composite coating on the surface of the substrate. Time 120min. ...

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