RU2251538C2 - Glass-metal decorative coating and a method of its realization - Google Patents

Abstract

FIELD: glass industry; dressing of a glass and products made out of glass.

SUBSTANCE: the invention is pertinent to the field of glass industry, in particular, to dressing of a glass and products made out of glass and may be used in a glass industry. The glass-metal coating is formed by plasma spraying from melted glass drops with impregnations of a non-ferrous metal powder. The method of application of such a coating provides for the use of a plasma spraying of a glass tube filled with a powder of non-ferrous metal or in the arbitrary ratio filled with a mix of a powder of non-ferrous metal and a glass powder with a grain structure of 50-500 nanometers, which is manually or automatically fed into a plasma torch. A spraying is conducted with the help of a plasma generator of 9 kW and a consumption of argon equal to 2.0 m³/h. During the spraying it creates a mix of a glass melt with a metal powder with a thermal coefficient of the linear expansion of the sprayed glass, which decreases the strain in the coating and in a glass substrate down to 2 MPa. The offered method allows to have a basically new glass-metal decorative coating with a high strength of coupling and significantly to reduce power inputs for dressing of a glass and items made out of it.

EFFECT: the invention ensures production of the basically new glass-metal decorative coatings with a high strength of coupling and to reduce power inputs for dressing of a glass and items made out of it.

3 cl, 2 tbl, 2 ex

Description

The invention relates to the field of decorating glass and glassware and can be used in the glass industry at the technological stage of applying decorative coatings to glass household goods (glasses, wine glasses, glasses, glasses, vases, mugs, plates, etc.).

Upon receipt of composite coatings on ceramic and metal substrates, powder and rod spraying are used. In plasma spraying, it is recommended to use powders of metals, oxides, and other compounds with a size of 20-50 μm, and in bar spraying, metal wire and ceramic rods [1].

A known method of decorating glassware by plasma spraying of metals, in which for decorating glassware using a copper wire d = 0.8-1.5 mm, which is sprayed onto a glass substrate with a plasma torch GN-5r electric arc plasma torch UPU-3 [2]. The disadvantage of this method is the low adhesion strength of the decorative metal coating to the glass substrate, equal to 1.6 MPa with a copper layer thickness of 100 nm [2]. Due to the fact that copper and glass have different values of the thermal coefficient of linear expansion (TECL of high-grade Na-Ca-Si glass is 102 · 10 ^-7 deg ^-1 ; TECL of copper is 170 · 10 ^-7 deg ^-1 ), when spraying self-peeling of the coating is observed on the glass substrate of a metal layer with a thickness of more than 400 nm due to the accumulation of significant internal stresses, which can reach about hundreds of MPa [1; p.50].

The closest technical solution is a method of decorating glass products by plasma spraying of glass powders, including heating the product to 523 K, applying a stencil, plasma spraying of decorating glassy material in the form of powders with sizes of 80-250 nm [3]. The adhesion strength of the coating obtained by this method can be approximately 12 MPa, but this method has the following disadvantages:

- With plasma spraying of glass powders it is impossible to use glass powders with a grain composition of less than 80 nm and more than 250 nm.

- Before spraying the glass powders of the above fractions in order to eliminate microcracks in the glass substrate, the glassware must be heated to 523 K. This lengthens the process of applying decorative coatings and increases the cost of finished products.

The present invention solves the problem of obtaining a fundamentally new composition of the glass-metal decorative coating on a glass substrate with high adhesion strength at any coating thickness, as well as expanding the size range of the used glass powders (the possibility of using metal powders and glass powders with particle sizes of less than 80 nm or more than 250 nm )

To achieve this technical result, it is proposed to use glass tubes d = 3.0-5.0 mm filled with non-ferrous metal powder or a mixture of metal powder and glass powder in an arbitrary ratio, with a grain composition of 50-500 nm, which are introduced into the plasma torch at the rate of plasma-forming gas 2.0 m ³ / h and a plasma torch power of 9 kW.

A comparative analysis of the proposed solution with the known shows that it meets the criterion of “novelty”, because allows you to get a fundamentally new glass-metal coating by combining powder and rod spraying by spraying a glass tube filled with non-ferrous metal and / or glass powder. Moreover, this technical solution allows to increase the adhesion strength of the decorative coating to the glass substrate due to the fact that when spraying, a mixture of glass melt with metal is formed with a thermal coefficient of linear expansion of the sprayed glass, which reduces the voltage in the coating and substrate to 2 MPa. An increase in the adhesion strength of such a coating as compared to a glass-powder coating is also explained by the fact that the molten glass-metal particle, ceteris paribus, has a larger mass and is soldered into the substrate to a greater depth upon impact with a glass substrate. In addition, this method makes it possible to expand the range of sizes of glass powders, both in the direction of reduction, and in the direction of increase, almost twice.

The inventive step is confirmed by the fact that the use of the proposed method:

- allows you to get a fundamentally new composition of the glass-metal coating, in addition, having higher strength characteristics compared with the known decorative coatings on glass;

- glass-metal coating is applied due to the combination of rod and powder spraying by introducing into the plasma jet a glass tube with a diameter of 3.0-5.0 mm filled with glass powder and non-ferrous metal in an arbitrary ratio;

- the strength of the obtained decorative coating with a glass substrate exceeds the known ones due to the fact that the stresses are reduced to a safe level (3 MPa according to GOST 30407) due to the formation of an intermediate diffusion zone when soldered into a glass substrate, and the coating does not peel even at a thickness of 400 nm or more ;

- eliminates the preheating of the substrate to 523 K, which reduces energy costs;

- allows you to spray glass powders in the range of 50-500 nm, since they are in a glass tube and the melting of the glass powders occurs together with the glass tube body;

The result is explained by the fact that the introduction of a glass tube with a metal powder into the plasma torch contributes to the formation of droplets of glass melt mixed with shiny metal particles.

Upon impact on a glass substrate, a molten glass particle mixed with shiny metal particles is deformed and soldered into its surface. Due to the fact that the thermal expansion coefficient of the sprayed glass tube and the glass substrate are close, there are no significant stresses in the substrate, since an intermediate diffusion zone forms between the coating and the glass substrate. Due to this, the adhesion of the decorative coating to the substrate significantly increases and the stress in the product decreases. In addition, a drop of molten glass with metal particles has a larger mass and, upon impact with the substrate, it is soldered to a greater depth equal to 320-350 nm, which also contributes to an increase in strength.

The most optimal is the diameter of the glass tube within 3-5 mm, because in production conditions the use of glass tubes with a diameter of less than 3 mm is laborious and economically impractical. The use of glass tubes with a diameter of more than 5 mm leads to the formation of large drops of melt with a diameter of more than 3000 nm on the surface of the substrate and microcracks in the glass substrate.

In studies it was found that the maximum adhesion strength of the glass-metal coating with the substrate is achieved with the following plasma torch operation parameters: power 9 kW, plasma-forming gas flow rate - 2.0 m ³ / h.

In the proposed method, when decorating, glass powders with a diameter of 50-500 nm can be used. When using larger glass powders, microcracks form in the glass substrate.

Thus, the result of using the proposed invention is to increase the competitiveness of products due to:

- expanding the range of products with a new glass-metal decorative coating with high strength characteristics;

- reducing the cost of products by reducing the duration of the process and energy costs.

A comparative analysis of the processing modes and properties of the coatings obtained by the proposed method in comparison with the methods of rod and powder spraying are given in table 1. Technological modes of operation of the plasma torch are shown in table 2.

The proposed method for producing a glass-metal coating is illustrated by the following examples.

Example No. 1. The starting material was copper powder with a grain composition of 20-50 nm and glass rods with a diameter of 3.0 mm, a length of 300-350 mm, made of Na - Ca - Si glass of the following chemical composition, wt.%: SiO ₂ - 71.0; Na ₂ O - 13.0; K ₂ O - 4.0; CaO - 6.0; Al ₂ O ₃ - 1.0; SO ₃ - 0.5. Glass tubes were sealed on one side and filled manually with copper powder.

For spraying, a plasma torch GN-5r of an electric arc plasma torch UPU-8M was used. The parameters of the plasma torch were as follows: argon flow rate - 2.0 m ³ h; power is 9 kW.

For decorating we took a glass of wine No. 204209, which is commercially available by the glass factory of JSC Red Glass Glass Factory OJSC. A stencil with a pattern of 6.5 cm ² made of copper or aluminum foil was placed on the glass, and the product was installed at a distance of 300 mm from the plasma torch GN-5p. A glass tube with metal powder was manually introduced into the plasma torch. A molten stream of particles of a mixture of glass and metal was sprayed onto the glass product for 25-30 seconds. After spraying, a stencil was removed from the wine glass. zovyvalos quality decorative coating that combines transparency of glass and metal gloss. The coating thickness was 300 ± 25 nm. The magnitude of the internal stress is less than 3 MPa.

Example No. 2. The starting material was: aluminum powder with a grain composition of 100-500 nm; green chrome glass powder with a grain composition of 100-500 nm of the following chemical composition, wt.%: SiO ₂ - 72.7; CaO - 6.8; MgO - 2.0; Na ₂ O - 15.0; K ₂ O - 2.0; SO ₃ - 0.5; In ₂ About ₃ - 1.0; Cr ₂ O ₃ - 0.5. Glass tubes with a diameter of 5 mm were made of lead crystal of the following chemical composition, wt.%: SiO ₂ - 56.5; Al ₂ O ₃ - 0.5; Na ₂ O - 1.0; K ₂ O - 15.0; SO ₄ 0.4; ZnO - 1.8; B ₂ O ₃ - 1.2; PbO - 24.0. For spraying, a plasma torch GN-5r of an electric arc plasma torch UPU-8M was used. The parameters of the plasma torch: argon flow rate - 2.0 m ³ / h; power is 9 kW.

Used for decorating glass №896203, a commercially available glass factory of "Glassworks" Red May. "In a glass superimposed stencil with a pattern area of 4.5 ^cm2 made of aluminum foil. The product was adjusted to a distance of 300 mm from the plasma torch cutoff GN- 5. A glass tube filled with a mixture of aluminum and green chrome glass powders in a ratio of 1: 1 was automatically introduced into the plasma torch, and a molten stream of particles of a mixture of metal and glass was sprayed onto the glass for 20–25 s.

After spraying, the stencil was removed from the glass. On the surface of the product a high-quality green coating was formed with white shiny inclusions of aluminum metal. The thickness of the decorative coating was 300 ± 25 nm with an internal stress of 2 MPa.

As can be seen from table 1, the coatings obtained by the proposed method, in comparison with the known ones, have greater adhesion strength due to lower stress and, in addition, for applying such coatings lower energy costs are required. Moreover, the selected parameters of the plasma torch are justified by the fact that it is in this mode of the plasma torch that the most durable coating is obtained (table 2).

table 2
Technological modes of the plasma torch No. p / p The parameters of the plasma torch Adhesion Strength, MPa power, kWt Argon consumption, m ³ h 1 6 1,5 11,4 2 nine 1,5 14.9 3 12 1,5 12.3 4 fifteen 1,5 7.6 5 6 2.0 14.6 6 nine 2.0 19.6 7 12 2.0 17,2 8 fifteen 2.0 9.8 nine 6 2,5 6.9 10 nine 2,5 11.6 eleven 12 2,5 7.8 12 fifteen 2,5 6.5

List of references

1. Demidenko L.M. Highly refractory composite coatings. - M.: Metallurgy, 1979, p. 53-55, 68.

2. On the plasma deposition of metals on products of varietal tableware. / German I.I., Krokhin V.P., Immortal B.C., Shitova T.I., Silko A.I. // Glass and ceramics. 1982. No. 12, p. 12-13.

3. Decoration of glass and products from it by plasma spraying. / Krokhin V.P., Immortal B.C., Panasenko V.A., Dryzh N.A., Nikiforov V.M. // Glass and ceramics. 1999. No. 3, pp. 12-14.

Claims (2)

1. A method of producing a glass-metal decorative coating on glass, comprising applying a stencil, plasma spraying a decorating material, characterized in that a 3.0 to 5.0 mm diameter glass tube sealed at one end is introduced into the plasma torch, filled in an arbitrary ratio with a colored powder mixture metal and glass powder with a grain composition of 50-500 nm or non-ferrous metal powder, and spraying is carried out with a plasma torch operating power of 9 kW and an argon flow rate of 2.0 m ³ / h. 2. A glass-metal decorative coating on glass obtained by the method according to claim 1, containing glass droplets interspersed with non-ferrous metal powder.