RU2282583C2 - Carbon polymer - Google Patents

Abstract

FIELD: carbon materials.

SUBSTANCE: carbon polymer contains homeotropically oriented carbon atoms and is made in the form of monocrystalline structure with tightly packed carbon atoms with sp-sp³ hybridization. Distance between adjacent carbon atoms in the same chain varies from 1.21 to 1.37 Å and chains are spaced from each other by 3.97 to 5.11 Å. Carbon polymer is prepared through vaporization of graphite by impulse arc discharge in vacuum chamber provided with one principal and two auxiliary plasma sources. Plasma beam is oriented onto substrate. Angle of plasma beam relative to substrate is varied depending on impulse parity. Atomically smooth film is thus prepared having coefficient of friction 0.05-.0.6 and showing wear and score resistance. polymer is further thrombus resistant and biologically compatible.

EFFECT: achieved high performance characteristics.

2 dwg, 1 tbl

Description

Technical field

The invention relates to carbon materials that can be used in nanotechnology, in medical technology, electronics, mechanical engineering, etc.

State of the art

Obtaining materials with new properties is one of the most urgent tasks in modern science.

A carbon coating based on a diamond-like material with an amorphous structure is known, which contains inclusions of the diamond phase and is pure carbon (RF application N 96110601).

Also known is a rolling bearing (RF application N 2000109596) containing an inner and an outer ring and a rolling body, while the rolling bodies and / or the raceway are coated with diamond-like carbon in a mixture with metal containing alternating layers.

There is also a method of forming anti-friction and anti-wear coatings on the friction surfaces of friction pair elements (RF patent N 2139456), comprising applying an epilam layer from solutions based on perfluoropolyoxyalkylene carboxylic acids, in which a glassy silicon dioxide film is applied to the friction surfaces of the friction pair elements.

Also known is the design of a roller bearing (US Pat. No. 6,234,679), in which a coating comprising a carbon nitrided layer and a substrate located between the outer layer and the base is applied.

A polymorphic carbon compound of a volume-centered cubic structure with certain lattice parameters is also known (RF patent N 2108288).

A carbon polymer is also known, where the carbon structure of linear carbon chains forming the film is oriented normally to the surface plane (VALevchenko, VGBabaev, MBGuseva, VNMatveenko. The carbon films as a unique orienter for epitropic liquid crystals. The 10 ^th European Conference on Diamond, Diamond-Like Materials, Carbon Nanotubes, Nitrides & Silicon Carbide, 12-17 September 1999, Prague Hilton Atrium Czech Republic, p. 62).

Polycrystalline abrasive carbon material is also known (Russian patent N 2136483) containing Sp ¹ / Sp ² / Sp ³ hybridization.

Closest to the claimed invention is a carbon material tetracarbon with perpendicularly oriented carbon atoms to the plane of the film (US patent N 6355350). The material has a polycrystalline structure with a tight packing of carbon atoms, while the minimum distance between the carbon chains is from 4.8 Angstroms (prototype).

The disadvantages of the known materials are:

- low tribological properties, in particular a large coefficient of friction;

- insufficiently high wear resistance;

- insufficiently high strength;

- insufficient hardness;

- insufficient scoring resistance;

- insufficient temperature stability;

- low corrosion resistance.

Disclosure of invention

The aim of the invention is to increase the tribological properties of the material, in particular the reduction of friction, as well as an increase in hardness, wear resistance, atom packing density, scoring resistance and temperature stability.

This goal is achieved in that the carbon polymer with homeotropically oriented carbon atoms is made in the form of a single crystal structure with a dense packing of carbon atoms and sp-sp ³ hybridization.

This goal is also achieved by the fact that the distance between adjacent carbon atoms in one chain is more than 1.21 Å.

This goal is also achieved by the fact that the polymer has a two- or three-dimensional structure of a linear-chain carbon with a homeotropic type of orientation of carbon atoms and a distance between carbon chains from 3.97 to 5.11 Å.

This goal is also achieved by the fact that in the single crystal structure and / or on the surface of the single crystal structure there are adsorption centers containing groups of chemical elements (N) (OH), (NHx) individually or in combination with each other.

This goal is also achieved by the fact that the polymer density is from 2.6 g / cm ³ to 3.4 g / cm ³ .

This goal is also achieved by the fact that the carbon polymer is made in the form of a film.

This goal is also achieved by the fact that the polymer is a thromboresistant biocompatible material.

This goal is also achieved by the fact that the polymer is connected to other materials through carbon atoms and / or adsorption centers.

Brief Description of the Drawings

The invention is illustrated by drawings, where Fig. 1 shows the structure of a carbon polymer, and Fig. 2 shows the structure of a carbon polymer with alloying elements.

Polymer 1 (Fig. 1) contains homeotropically oriented carbon atoms 2 and is made in the form of a single crystal structure with a dense packing of carbon atoms larger than that of diamond. The distance between adjacent carbon atoms 2 in one chain 3 is more than 1.21 angstroms, and the distance between the chains is from 3.97 to 5.11 angstroms. The single crystal structure of the polymer contains sp-sp ³ hybridization.

On the surface of the single crystal structure, there are adsorption centers 4 (FIG. 2) associated with carbon atoms 2. Adsorption centers 5 can be located in the bulk of the single crystal structure and bonded to carbon atoms 2 and 6.

Adsorption centers 4 and 5 consist of groups of chemical elements (N) (OH), (NHx) bonded to carbon atoms 3 individually or in combination with each other.

The packing density of carbon atoms exceeds the packing density of atoms in diamond and the polymer density is from 2.6 g / cm ³ to 3.4 g / cm ³ . The polymer may be made in the form of a film. The polymer can be bonded to other materials (metals, composites, ceramics, etc.) through carbon atoms and / or adsorption centers.

The implementation of the invention

Monocrystalline carbon polymer 1 (Fig. 1) is obtained by pulsed condensation of carbon plasma in combination with additional irradiation of the substrate with inert gas ions.

A method of obtaining a carbon polymer coating is carried out in a vacuum chamber (VK). The VK case is made so that in addition to the main plasma source, there are two additional sources in the case, which allows the dynamics to expand the technological capabilities of the materials obtained. In the center of the VK housing there is a multifunctional, controlled thermostat, on which materials are fixed for the deposition of a carbon polymer coating. A carbon polymer with a single crystal structure is obtained by evaporation of graphite from a graphite target located in the VC together with the plasma source and having a purity of 99-99.9999%. For this, a carbon plasma with a synthesized beam of inert gas ions is created in the VC case. The evaporation of graphite from a graphite electrode is produced by a pulsed arc discharge in a vacuum chamber, which is pre-vacuum to a pressure of 12 torr. The plasma flow from carbon atoms and clusters that forms around the cathode during the evaporation of graphite is directed for deposition to the surface of the substrate material, relative to which the angle of the plasma flow varies depending on the parity of the pulse. Along with the process of graphite evaporation and the formation of an alternating plasma flow, the surface of the material is activated by an inert gas with an energy of 100-3000 eV. Plasma with a density of 1 × 10 ¹⁴ cm ^{-3 is} generated. The pulse duration is set to not more than 900 μs and not less than 100 μs. The pulse frequency is set depending on the technology of using the coating at least 1 Hz and not more than 10 Hz. The formation of a single-crystal polymer on a substrate is carried out at pressures in a vacuum chamber of 1 × 10 ^-1 -1 × 10 ^-3 Pa and operating temperatures of the substrate (depending on the material) from 0 ° to 300 ° C. Thus, the necessary conditions are created under which the surface of the substrate captures carbon clusters in the form of carbon atoms, combined in a strictly linear chain, and their uniform growth. A uniform coating of the carbon polymer in the form of a film on the working surface of the substrate material is obtained with a density of from 2.6 g / cm ³ to 3.4 g / cm ³ . A VK device and a method for producing a carbon polymer with a single crystal structure provide the deposition of an atomically smooth film on the surface of various materials and regardless of the surface topography.

The resulting single-crystal structure of the carbon polymer is confirmed by electron diffraction, Auger spectroscopy, Raman spectroscopy and atomic force microscopy.

The single crystal polymer 1 has good adhesion and can be deposited on various types of substrates (metals, dielectrics, ceramics, etc.).

Polymer 1 is characterized by a uniaxial texture and anisotropic electrical conductivity, is tunnel transparent, has a low coefficient of friction, a hardness close to diamond, and excellent adhesion to substrates.

The adsorption centers 4 are located both on the surface of the single crystal structure 1 and in the bulk of the single crystal structure 1. The groups of chemical elements (N), (OH), (NHx) are used as adsorption centers.

Table 1 shows the main differences of the inventive carbon polymer from similar materials.

The claimed invention - a carbon polymer, in contrast to tetracarbon, due to its structure (tight packing of carbon atoms, single crystal structure, hybridization) allows to achieve a new result - higher tribological parameters, for example - reduce friction. So, for tetracarbon, the friction coefficient is 0.1, and for the inventive carbon polymer is 0.05-0.06. By means of the proposed technical solution, a result was achieved that satisfies long-standing needs (reduction of friction, increase of operational characteristics - increase of wear resistance, scoring resistance, etc.).

Table 1:
The main differences of the inventive carbon polymer. Material Name Material according to patent RU N 2136483 Tetracarbon Carbon polymer Hybridization type Sp ¹ / Sp ² / Sp ³ - Hybridization * Sp ¹ Hybridization Sp ¹ -Sp ³ - hybridization Distance between carbon chains - The minimum distance between carbon chains is 4.8 The minimum distance between carbon chains is 3.97 Structure type Polycrystalline structure Polycrystalline structure Single crystal structure Coefficient of friction - Coefficient of friction 0.1-0.2 Coefficient of friction 0.05-0.06

Industrial applicability

When analyzing the invention for compliance with the criterion of "novelty", it was revealed that part of the features of the claimed combination is new, therefore, the invention meets the criterion of "novelty".

When analyzing the invention for compliance with the criterion of "inventive step", it was revealed that the technical solution of the analyzed object is new, therefore, the features meet the criterion of "inventive step", since it represents a new set of features as a combination of well-known features and a new technical property, and also represents a new structure and communication elements. In addition, by means of the proposed device, a result was achieved that meets long-standing needs (reduction of friction, increase of operational characteristics - increase of wear resistance, scoring resistance, etc.).

The invention can be used in industry, can be replicated and, therefore, meets the criterion of "industrial applicability".

The advantages of the proposed technical solution lies in the creation of optimal microstructures that best meet the working conditions of antifriction coatings and allow achieving high tribological parameters.

Claims (1)

A carbon polymer with homeotropically oriented carbon atoms, characterized in that it is made in the form of a single crystal structure with a tight packing of carbon atoms with sp-sp ³ hybridization, while the distance between carbon chains is from 3.97 to 5.11 Å.

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