Metal-glass composite

Abstract

Provided is a metal-glass composite obtained by preparing spraying glass powder having a coefficient of thermal expansion according to a metal base material to be subjected to spraying, suppressing bubbles contained in a glass substance, and increasing the strength such as impact resistance. The present invention comprises a metal base material part that is formed from an iron material of a body-centered cubic crystal system and a sprayed glass part that is formed on the metal base material part so as to have a thickness of 10-2000 μm, wherein a glass material that forms the sprayed glass part contains 90 mass% or more of a main component (D), which is a total of the following: 35-70 mass% of a first group component (A), which is SiO2; 18-30 mass% of a second group component (B), which is a total of 9-15 mass% of B2O3, 5-9 mass% of Li2O, and 4-10 mass% of Na2O; and 10-30 mass% of a third group component (C), which is a total of 0-15 mass% of BaO, 2-15 mass% of TiO2, 0-8 mass% of Al2O3, and 0-15 mass% of ZnO.

Description

Metallic Glass Composite

[0001] The present invention relates to a metallic glass composite, and more particularly to a metallic glass composite in which glass particles are thermally sprayed onto a metal surface and firmly adhered to the surface.

[0002] Thermal spraying is used to form a glassy coating on a metal substrate. When a glassy coating is applied to a metal substrate by thermal spraying, the glass adheres to the metal substrate more firmly than enamel, forming a coating. Therefore, thermal spraying is suitable for applications requiring durability.

[0003] In a thermal spraying device, a material to be sprayed, such as glass or ceramics, is mixed with a carrier gas. A separately supplied gas and a high current generate plasma, which generates high heat and melts the sprayed glass powder, which is made of glass granules. The molten sprayed glass powder is then ejected from the thermal spraying device toward the metal substrate to be sprayed (see Patent Documents 1 and 2, etc.).

[0004] The thermal expansion coefficient (linear expansion coefficient) of the metal substrate and the glassy material of the sprayed glass powder differ. Due to their specific heat, the metal substrate cools faster. Because the rate of volumetric contraction differs between the metal substrate and the sprayed glass powder, it is necessary to control the expansion coefficient, making spraying between dissimilar materials extremely difficult.

[0005] The inventors developed the thermal spray glass powder and thermal spraying method disclosed in Patent Document 1, and the thermal spraying apparatus disclosed in Patent Document 2. The inventors established robust thermal spraying between dissimilar materials, a metal substrate and the glassy substance of the thermal spray glass powder, and have now produced a metallic glass composite. According to the disclosure of Patent Document 1, the surface of the metal substrate to be thermally sprayed is roughened by sandblasting or the like and then heated. A coating of glassy substance derived from the sprayed glass powder melted by thermal spraying is then formed on the surface. It is believed that the glassy substance derived from the sprayed glass powder penetrates into the surface of the roughened metal substrate in this way, improving adhesion between the metal substrate and the glassy substance.

[0006] JP 2013-216977 A JP 2021-130841 A

[0007] The inventors then conducted extensive research into the formation of glass by thermal spraying on the surface of a metal substrate. They discovered that, due to differences in thermal expansion coefficients depending on the type of metal substrate, it is necessary to adjust the thermal expansion coefficient of the sprayed glass powder depending on the type. They also discovered that bubbles inevitably form when the sprayed glass powder is melted by thermal spraying and applied to the metal substrate, reducing the impact resistance of the resulting glass in the metallic glass composite.

[0008] The present invention has been made in view of the above points, and provides a metallic glass composite in which a metal substrate and a glassy dissimilar material, a thermal spray glass powder, are integrated by thermal spraying. The thermal spray glass powder has a thermal expansion coefficient corresponding to the metal substrate to be thermal sprayed, and bubbles contained in the glassy material formed on the metal substrate after thermal spraying are suppressed, thereby improving strength such as impact resistance.

[0009] That is, the metallic glass composite of the embodiment has a metal substrate made of a body-centered cubic iron material and a sprayed glass portion formed on the metal substrate with a film thickness of 10 to 2000 μm, and the glass material forming the sprayed glass portion contains SiO as the first group component (A). ２ : 35 to 70 mass%, and as the second group component (B), B ２ O ３ : 9 to 15 mass%, Li ２ O: 5 to 9 mass % and Na ２ O: 4 to 10 mass% and a total of 18 to 30 mass%, and as a third group component (C), BaO: 0 to 15 mass% and TiO ２ : 2 to 15 mass% and Al ２ O ３ : 0 to 8 mass % and ZnO: 0 to 15 mass % in total to 10 to 30 mass %, the first group component (A), the second group component (B), and the third group component (A) in total contain 90 mass % or more as the main component (D), and the linear expansion coefficient of the glass material from room temperature to 300°C is 9 to 11 (×10 ６ / °C), and the area ratio of bubbles of 1 μm or more in the cross section in the thickness direction of the sprayed glass portion is less than 40%.

[0010] The metallic glass composite of the embodiment has a metal substrate made of a face-centered cubic iron material and a sprayed glass portion formed on the metal substrate with a film thickness of 10 to 2000 μm, and the glass material forming the sprayed glass portion contains SiO as a first group component (A). ２ : 50 to 60 mass%, and as the second group component (B), B ２ O ３ : 2 to 8 mass% and Li ２ O: 8 to 15 mass % and Na ２ O: 8 to 20 mass% and a total of 25 to 35 mass%, and as a third group component (C), BaO: 3 to 12 mass% and TiO ２ : 4 to 15 mass% and Al ２ O ３ : 0 to 5 mass % and ZnO: 0 to 5 mass % in total to 10 to 20 mass %, the first group component (A), the second group component (B), and the third group component (A) in total contain 90 mass % or more as the main component (D), and the value of the linear expansion coefficient of the glass material from room temperature to 300°C is 14 to 17 (×10 ６ / °C), and the area ratio of bubbles of 1 μm or more in the cross section in the thickness direction of the sprayed glass portion is less than 40%.

[0011] Furthermore, the difference between the linear expansion coefficient of the glass material of the metallic glass composite and the linear expansion coefficient of the metal substrate may be within 15%.

[0012] Furthermore, the metallic glass composite may have a molten solidified portion in which the sprayed glass portion is embedded in the metal substrate portion at the boundary between the metal substrate portion and the sprayed glass portion in the cross section, and the molten solidified portion may have a thickness of 0.3 μm or more.

[0013] Furthermore, the sprayed glass portion of the metallic glass composite may have an area ratio of bubbles of 1 μm or more that are present in an area within 30% of the thickness of the sprayed glass portion at the boundary between the metal substrate portion and the sprayed glass portion in the cross section, starting from the boundary, of 50% or less.

[0014] Furthermore, the thickness of the sprayed glass portion of the metallic glass composite may be 10 to 100 μm, and the area ratio of bubbles of 1 μm or more in size in a cross section in the thickness direction of the sprayed glass portion may be less than 10%.

[0015] Furthermore, the components other than the main component (D) of the glass material of the metallic glass composite are auxiliary components (E), which include CaO, SrO, MgO, P ２ O ５ , K ２ O.V. ２ O ５ , Cr ２ O ３ , MnO ２ , Fe ２ O ３ , Co ３ O ４ , NiO ２ , CuO, Y ２ O ３ , ZrO ２ , Nb ２ O ２ , MoO ３ , SnO ２ , Sb ２ O ３ , W.O. ３ , PbO, Bi ２ O ３ , La ２ O ３ , CeO ２ , Pr ６ O １１ , Nd ２ O ３ , Sm ２ O ３ , Gd ２ O ３ It may be one or more of the above.

[0016] The metallic glass composite of the present invention is a metallic glass composite in which a metal substrate and a glassy dissimilar material, a thermal spray glass powder, are integrated by thermal spraying. The thermal spray glass powder is prepared to have a thermal expansion coefficient that matches the metal substrate to be thermal sprayed, and air bubbles contained in the glassy material formed on the metal substrate after thermal spraying are suppressed, thereby increasing strength such as impact resistance.

[0017]

[0023] Figure 1 shows (A) a cross-sectional schematic diagram of a plate material, (B) a cross-sectional schematic diagram of a perforated plate material, (C) a cross-sectional schematic diagram of a pipe material, and (D) a cross-sectional schematic diagram of a bolt material, all relating to metallic glass composites, and (E) a schematic diagram showing the compositional relationship of glass materials. (A) A schematic diagram showing the compositional relationship of glass materials, and (B) a cross-sectional schematic diagram showing the structure of a metallic glass composite. (A) A 100x magnified cross-sectional photograph and (B) a 1000x magnified cross-sectional photograph of a metallic glass composite of prototype example number G1. (A) A 100x magnified cross-sectional photograph and (B) a 1000x magnified cross-sectional photograph of a metallic glass composite of prototype example number G2. (A) A 100x magnified cross-sectional photograph and (B) a 1000x magnified cross-sectional photograph of a glass material of a metallic glass composite of prototype example number G6. (A) A 100x magnified cross-sectional photograph and (B) a 1000x magnified cross-sectional photograph of a glass material of a metallic glass composite of prototype example number G11. (A) is a 100x magnified cross-sectional photograph and (B) is a 1000x magnified cross-sectional photograph of the glass material of the metallic glass composite of prototype example number G13. (A) is a 100x magnified cross-sectional photograph and (B) is a 1000x magnified cross-sectional photograph of the glass material of the metallic glass composite of prototype example number G19. (A) is a 100x magnified cross-sectional photograph and (B) is a 1000x magnified cross-sectional photograph of the glass material of the metallic glass composite of prototype example number H5. (B) is a graph showing the relationship between the area ratio of all bubbles and the height of a falling ball. (C) is a graph showing the relationship between the area ratio of bubbles in the boundary portion and the dielectric strength.

[0018] The metallic glass composite of the embodiment is a metal-glass composite in which a glassy coating is formed on the entire or part of the surface of various types of metal by thermal spraying. The glassy material is prepared in a powder form such as frit and supplied to a thermal spraying device. The glassy powder is then instantaneously melted by plasma spraying in the thermal spraying device and sprayed toward the target metal substrate. As a result, the molten glassy material adheres to the metal substrate and cools, and the glassy material adheres to the metal and becomes integrated.

[0019] 1A to 1D are schematic diagrams of metallic glass composites 1A, 1B, 1C, and 1D in which a sprayed glass portion 20 is formed on (the surface of) a metal substrate portion 10.

[0020] FIG. 1(A) shows a metallic glass composite 1A in which a sprayed glass portion 20 is formed on the surface of a sheet metal-like metal substrate 11 (10). The sprayed glass portion 20 is formed by spraying on the surface of a metal substrate 11 such as a steel plate. As a result, the impact resistance, corrosion resistance, etc. of the steel plate are imparted. FIG. 1(B) shows a metallic glass composite 1B in which a sheet metal-like metal substrate 12 (10) is prepared having a hole 15 that allows for fastening with bolts, rivets, etc. and for connecting other members, and the sprayed glass portion 20 is formed on the surface of the metal substrate 12. The sprayed glass portion 20 is also attached to the hole 15 and the periphery of the hole 15, thereby improving resistance to wear, corrosion, etc. due to contact between metals.

[0021] FIG. 1(C) shows a metallic glass composite 1C in which a sprayed glass portion 20 is formed on the surface of a metal substrate portion 13 (10) of a pipe material. In the case of the metallic glass composite 1C, it can be combined with another cylindrical electrode to form an electrode for silent discharge (see Patent Document 1, etc.). The insulating properties due to the glassy nature of the sprayed glass portion 20 are utilized. In FIG. 1(D), a bolt is used as the metal substrate portion 14 (10). By forming the sprayed glass portion 20 on the surface of the bolt, the corrosion resistance of the bolt is improved, and the resistance to breakage of the bolt due to weakening caused by corrosion is increased. Of course, the metallic glass composite disclosed in FIG. 1 is only one example, and the metallic glass composite is not limited to the illustrated embodiment.

[0022] In the metallic glass composite of the embodiment, the thickness of the sprayed glass portion 20 is in the range of 10 to 2000 μm. If the thickness of the sprayed glass portion 20 is less than 10 μm, the molten glass material is likely to form stripes or spots on the surface of the metal substrate 10. This makes it difficult to homogenize the glass material deposition. Furthermore, if the thickness of the sprayed glass portion 20 exceeds 2000 μm, the thickness of the sprayed glass portion 20 becomes too large, and cracks and peeling are likely to occur due to the difference in thermal expansion coefficients between the metal substrate 10 and the sprayed glass portion 20. In particular, it becomes more difficult to control bubbles contained in the sprayed glass portion 20, as described below.

[0023] In preparing the metallic glass composite of the embodiment, the composition of the glass material constituting the sprayed glass portion is determined by the difference in thermal expansion coefficient (linear expansion coefficient) depending on the type of metal in the metal substrate, particularly the type of iron material (iron alloy). The metallic glass composite of the embodiment mainly uses body-centered cubic iron material and face-centered cubic iron material as the metal substrate.

[0024] Body-centered cubic iron materials include martensitic stainless steel, ferritic stainless steel, etc., such as stainless steels SUS409, SUS420, SUS430, etc., and general structural rolled steels such as SS400. SUS409 and SS400 are used in the examples described below. Face-centered cubic iron materials include austenitic stainless steel, such as SUS304, SUS310, SUS316, etc. SUS304 is used in the examples described below.

[0025] The composition of the glass material constituting the sprayed glass portion must be adjusted to correspond to the type of metal in the metal substrate. The schematic diagram in Figure 2(A) shows an overview of the composition of the glass material constituting the sprayed glass portion. First, the main component (D) is composed of the first group component (A), the second group component (B), and the third group component (C). The main component (D) accounts for 90 mass% or more of the glass material per unit weight. The remaining components of the glass material are the auxiliary component (E). Of course, unavoidable impurity components may be mixed into the glass material. Hereinafter, mass% and weight% are treated as synonyms. The mass% ratios between the first group component (A), the second group component (B), and the third group component (C) vary depending solely on whether the iron material is a body-centered cubic iron material or a face-centered cubic iron material.

[0026] The first group component (A) is SiO ２ The first group component (A) SiO ２ is the main component of the glass material that constitutes the sprayed glass portion, and mainly improves corrosion resistance, hardness (abrasion resistance), antifouling properties, electrical insulation, voltage resistance, etc. In the case of a metal substrate made of body-centered cubic iron material, the blending amount of the glass material is 35 to 70 mass %. In the case of a metal substrate made of face-centered cubic iron material, the blending amount of the glass material is 50 to 60 mass %.

[0027] SiO of the first group component (A) ２ If the blending ratio of the first group component (A) is below the respective lower limits, the properties of the final sprayed glass part, such as corrosion resistance, will be reduced. In addition, the sprayed glass part will be prone to age-related changes, such as whitening. ２ If the blending ratio of SiO exceeds the respective upper limits, the surface of the sprayed glass portion formed after thermal spraying is difficult to be flat. During thermal spraying, the metal substrate to be sprayed is heated to a temperature above the heat distortion temperature (1000°C or higher). ２ As the amount increases, the fire resistance of the glass material itself increases and its melting property during plasma spraying decreases, which increases the load on the spraying device and makes it difficult to obtain smoothness in the sprayed glass portion after melting.

[0028] SiO ２ The thermal expansion coefficient of SiO is smaller than that of each of the following components: ２ Increasing the amount of SiO reduces the thermal expansion coefficient of the entire glass material. In addition, the melting property during plasma spraying becomes low and the viscosity becomes high. ２ The amount of the glass material is determined based on the thermal expansion coefficient of the metal substrate of the body-centered cubic iron material or the thermal expansion coefficient of the metal substrate of the face-centered cubic iron material, as well as corrosion resistance and ease of spraying and melting. The amount of the glass material is determined based on the composition of the metal substrate, taking into account the adjustment of the thermal expansion coefficient.

[0029] The second group component (B) is a component that mainly adjusts the melting property and low viscosity of the glass material during melting. ２ O ３ , Li ２ O, Na ２ The second group component (B) is a component containing O. The total amount of the second group component (B) and the amount of each component contained in the second group component (B) are adjusted and blended in order to bring the thermal expansion coefficient of the glass material closer to the thermal expansion coefficient of the metal substrate.

[0030] B ２ O ３ promotes the melting property and low viscosity of the glass material during plasma spraying. ２ and is essential for adjusting the action of other ingredients. ２ O ３ The thermal expansion coefficient of SiO ２However, B ２ O ３ is SiO ２ On the contrary, it reduces corrosion resistance, hardness (wear resistance), electrical insulation, and voltage resistance, and accelerates deterioration over time. ２ O ３ The increase in the amount of B will impair the properties of the sprayed glass part. ２ O ３ is easily volatilized by heating during thermal spraying, and it is not easy to control the amount of volatilization. ２ O ３ As the heat evaporates, the thermal expansion coefficient of the glass material changes.

[0031] In the case of a metal substrate made of body-centered cubic iron material, B ２ O ３ In the case of a metal substrate made of a face-centered cubic iron material, the content of B in the glass material is 9 to 15 mass %. ２ O ３ is blended at 2 to 8 mass %. ２ O ３ If the blending ratio of B exceeds the upper limit, peeling and penetration (cracks) of the glass coating of the thermal sprayed glass portion formed on the surface of the metal substrate portion are likely to occur. ２ O ３ If the blending ratio is below the lower limit, the glass material will not be able to fully exhibit its melting property and low viscosity during plasma spraying, and will not be able to provide a suitable glass material.

[0032] Li ２ O promotes the melting property and low viscosity of the glass material during plasma spraying, and SiO ２ It is an essential component for adjusting the effects of other components. ２ O is relatively difficult to volatilize even during plasma spraying, and has the largest thermal expansion coefficient compared to other components. ２ O adjusts the thermal expansion coefficient of other components and also acts as a buffer material to develop the desired properties of the glass coating of the thermal sprayed glass portion. ２Oxygen reduces corrosion resistance to acids and alkalis and hardness (wear resistance). Furthermore, the glass material is more likely to recrystallize (to form lithium silicate crystals) during thermal spraying. While recrystallization improves corrosion resistance and other properties, it also reduces the thermal expansion coefficient of the resulting glassy coating. This reduction in the thermal expansion coefficient is difficult to control, and ultimately leads to crazing (cracks) on the surface of the substrate.

[0033] In the case of a metal substrate made of body-centered cubic iron material, Li ２ The blending amount of O is 5 to 9 mass %. In addition, in the case of a metal substrate made of iron material with a face-centered cubic crystal system, Li is contained in the glass material. ２ O is blended in an amount of 8 to 15 mass %. ２ If the blending ratio of O exceeds the upper limit, in addition to the above-mentioned problems such as peeling, deterioration of electrical insulation, voltage resistance, corrosion resistance, etc. becomes significant. ２ If the blending ratio of O is below the lower limit, the melting property and low viscosity during plasma spraying are not exhibited.

[0034] Na ２ Depending on the amount of O contained in the glass material, O increases the melting property of the glass material during plasma spraying, and at the same time increases the viscosity during melting. As a result, the glass material sprayed on the surface of the metal substrate to be sprayed becomes more easily adhered to the surface of the metal substrate, and the adhesive strength between the sprayed glass portion and the surface of the metal substrate is increased. In addition, Na ２ The increase in viscosity of the glass due to O causes a slight decrease in the fluidity of the molten glass material itself deposited on the surface of the metal substrate, and therefore the movement of bubbles caught in the spraying (bubbles gathering together and becoming larger due to fluidity) is also suppressed (see Examples below). ２ O contributes greatly to improving the smoothness of the sprayed glass part after plasma spraying and reducing the film thickness, and also improves the electrical insulation and voltage resistance. ２ O is Li ２ If the mass ratio (weight ratio) is the same as that of O, it improves the electrical insulation property and voltage resistance, and is also excellent in terms of functionality.

[0035] Na ２ The thermal expansion coefficient of O is Li ２Since it is the second largest after O, it is possible to easily design the thermal expansion coefficient of the glass material to match the thermal expansion coefficient of the metal substrate of the body-centered cubic iron material to be sprayed or the individual metal substrate of the face-centered cubic iron material. ２ The amount of O added is Li ２ It depends on the ratio of Na to O. ２ The viscosity at the time of melting that appears due to the addition of O is ２ O ３ The viscosity of the melt is different from that exhibited by the addition of CaO. ２ In the case of O, the viscosity at the time of melting tends to increase almost linearly as the amount of O added increases. ２ O ３ In the case of CaO, the viscosity during melting changes suddenly depending on the amount of CaO added. Therefore, Na is more effective than CaO in terms of ease of viscosity control during melting of the glassy material. ２ O is suitable.

[0036] However, Na ２ O is B ２ O ３ It is easily volatilized by plasma spraying, and the amount of volatilization is ２ Greater than O. Na ２ O is B ２ O ３ Therefore, in the case of a metal substrate made of body-centered cubic iron material, the thermal expansion coefficient is significantly different from that of the glass material. ２ The blending amount of O is 4 to 10 mass %. In addition, in the case of a metal substrate made of iron material with a face-centered cubic crystal system, Na is contained in the glass material. ２ O is blended in an amount of 8 to 20 mass %.

[0037] Na ２ The upper limit of the blending ratio of O is a range that takes into consideration the thermal expansion coefficient of the metal substrate of the body-centered cubic iron material to be sprayed or the individual metal substrate of the face-centered cubic iron material. ２ When the blending ratio of O is 20 mass % or more, Na ２The volatilization of O causes a large change in the composition of the sprayed glass portion itself after thermal spraying, which can cause the sprayed glass portion to peel off from the surface of the metal substrate or crack. In addition, the glass material melts and becomes thread-like in the thermal spraying device described below, hindering uniform spraying. In addition, in the case of a sprayed glass portion formed from a glass material containing a large amount of Na2O, the corrosion resistance and hardness (wear resistance) tend to decrease. ２ If the blending ratio of O is below the lower limit, the characteristics of increasing the meltability of the glass material and simultaneously increasing the viscosity during melting cannot be observed, and the desired electrical insulation properties and voltage resistance cannot be obtained.

[0038] B included in the second group component (B) ２ O ３ , Li ２ O, Na ２ Each component of O is a component that is relatively easily volatilized when the glass material is heated during plasma spraying. When a sprayed glass portion derived from the molten glass material is formed on the surface of the metal substrate, entrapment of bubbles is inevitable. Therefore, the characteristics of the glass material used in the metal glass composite of the embodiment are required to utilize the function attributable to the second group component (B), to converge to a glass material composition that takes into account the thermal expansion coefficient of the material of the metal substrate, and to suppress the amount of bubbles generated in the sprayed glass portion. If the amount of bubbles in the sprayed glass portion is excessive, the density of the sprayed glass portion itself is lost, which is likely to lead to a partial decrease in strength. In addition, dielectric breakdown is likely to occur due to fluctuations in the dielectric constant of the sprayed glass portion.

[0039] Therefore, in the glass material used in the metallic glass composite of the embodiment, when the second group component (B) is lumped together, in the case of a metal substrate made of a body-centered cubic iron material, the second group component (B) is blended in a total amount of 18 to 30 mass% in the glass material, and in the case of a metal substrate made of a face-centered cubic iron material, the second group component (B) is blended in a total amount of 25 to 35 mass% in the glass material.

[0040] The third group component (C) is a component that is blended mainly for the purpose of assisting the formation of glass in the sprayed glass portion that occurs after thermal spraying. The third group component (C) includes BaO, TiO ２ , Al ２ O ３, and ZnO.

[0041] BaO is a SiO ２ The more BaO is added, the more the melting property of the glass material increases, and the lower the softening temperature of the glass material during thermal spraying. ２ Although the effect is less than that of the increase in viscosity caused by O, the incorporation of BaO increases the adhesive strength of the glass material sprayed onto the surface of the metal substrate. For this reason, BaO improves the smoothness of the glass coating of the sprayed glass part formed after plasma spraying. Therefore, BaO contributes to reducing the film thickness of the sprayed glass part formed, and also improves the electrical insulation, voltage resistance, and relative dielectric constant of the sprayed glass part formed. BaO is a compound having a high affinity with LiO. ２ O, Na ２ If the amount of the alkaline component such as Li is the same as that of O, ２ O, Na ２ It has better electrical insulation and voltage resistance than O and other materials.

[0042] Therefore, in the case of a metal substrate made of a body-centered cubic iron material, the BaO content in the glass material is 0 to 15 mass%. Furthermore, in the case of a metal substrate made of a face-centered cubic iron material, the BaO content in the glass material is 3 to 12 mass%. If the BaO content in the glass material exceeds the upper limit, the viscosity of the glassy sprayed glass portion becomes extremely high when the glass material is plasma sprayed. As a result, the molten glass material melts and becomes filamentous in the spraying device described below, hindering uniform spraying. The coating of the sprayed glass portion formed after spraying may have reduced corrosion resistance and become brittle over time. In the case of a metal substrate made of a body-centered cubic iron material, the lower limit of the BaO content may be zero (0 mass%). Preferably, the lower limit of the BaO content is 3 mass%, similar to the case of a metal substrate made of a face-centered cubic iron material. Although it depends on the amount of other components added, this is because it is expected to improve the electrical insulation, voltage resistance, dielectric constant, etc. of the sprayed glass portion formed, and to improve the adhesive strength of the glass coating on the surface of the substrate.

[0043] TiO ２ is SiO in the glass material. ２ It is a component that assists in the formation of glass.２ The more the amount of TiO is added, the harder (wear resistance) the glassy coating of the thermal sprayed glass portion becomes. ２ also improves corrosion resistance, electrical insulation, and voltage resistance. ２ Therefore, in the case of a metal substrate made of a body-centered cubic iron material, TiO ２ In the case of a metal substrate made of a face-centered cubic iron material, TiO ２ is blended in an amount of 4 to 15 mass %.

[0044] If the blending ratio of TiO2 exceeds the upper limit, crystallization of the glass occurs when the glass material melted by heating in plasma spraying cools (slowly cools) to form the sprayed glass part. In other words, the thermal expansion coefficient decreases, making it more likely to peel off. Crystallization of the glass drastically reduces hardness, corrosion resistance, etc. If the blending ratio of TiO2 is below the lower limit, it becomes difficult to improve the electrical insulation, voltage resistance, relative dielectric constant, etc. of the formed sprayed glass part, and to achieve meltability during melting in plasma spraying, although this depends on the blending amounts of other components.

[0045] Al ２ O ３ is SiO in the glass material. ２ It is a component that assists in the formation of glass. ２ O ３ Li has the effect of improving the corrosion resistance, hardness (abrasion resistance), electrical insulation, voltage resistance, etc. of the glassy coating of the thermally sprayed glass portion formed by the molten glass material, and of preventing recrystallization. ２ In order to improve the recrystallization of the glassy part of the thermal sprayed glass due to the inclusion of O, Al ２ O ３ Therefore, in the case of a metal substrate made of body-centered cubic iron material, the glass material contains Al. ２ O ３ In the case of a metal substrate made of a face-centered cubic iron material, the content of Al in the glass material is 0 to 8 mass %. ２ O ３ is blended in an amount of 0 to 5 mass %. ２ O ３If the blending ratio of Al exceeds the upper limit, the melting property of the glass material during plasma spraying is reduced and the viscosity is increased extremely. ２ O ３ The lower limit of the blending ratio of Al may be zero (0 mass %), and is preferably 2 mass %. ２ O ３ The incorporation of improves the corrosion resistance of the sprayed glass portion and the effect of preventing recrystallization.

[0046] ZnO is a SiO ２ ZnO is a component that assists in the formation of glass. As with BaO, the more ZnO is added, the more the melting property of the glass material increases and the softening temperature of the glass material during thermal spraying decreases. However, Na ２ Although the effect is less than that of the increase in viscosity caused by O, the incorporation of ZnO increases the adhesive strength of the sprayed glass portion sprayed on the surface of the metal substrate. For this reason, ZnO, like BaO, improves the smoothness of the glassy coating of the sprayed glass portion formed after plasma spraying, and contributes to reducing the thickness of the glassy film of the sprayed glass portion. In addition, the electrical insulation, voltage resistance, and dielectric constant of the glassy material of the sprayed glass portion formed are improved. ZnO has the same effect as Li ２ O, Na ２ If the amount of the alkaline component such as Li is the same as that of O, ２ O, Na ２ It has better electrical insulation and voltage resistance than O and other materials.

[0047] In the case of a metal substrate made of a body-centered cubic iron material, the ZnO content in the glass material is 0 to 15% by mass. In the case of a metal substrate made of a face-centered cubic iron material, the ZnO content in the glass material is 0 to 5% by mass. If the ZnO content exceeds the upper limit, the viscosity of the molten glass material increases when plasma spraying the glass material. As a result, the molten glass material melts and becomes filamentous in the thermal spraying device described below, hindering uniform spraying. Even in the glassy portion formed after thermal spraying, crystallization of the glass may occur, reducing the thermal expansion coefficient and potentially inducing peeling. As a result, the corrosion resistance of the glassy coating of the sprayed glass portion decreases and it becomes brittle over time. In particular, the crystallization of the glassy portion cannot be controlled. The lower limit of the ZnO content may be zero (0% by mass) regardless of whether the metal substrate is made of a body-centered cubic iron material or a face-centered cubic iron material. Preferably, it is 2% by mass. Depending on the amount of other components added, this tends to contribute to improving the electrical insulation, voltage resistance, dielectric constant, etc. of the glassy material in the sprayed glass portion formed after thermal spraying, and to improving the adhesion strength of the glassy material on the surface of the substrate.

[0048] The purpose of the third group component (C) is to improve the glass quality of the sprayed glass portion formed after thermal spraying. Therefore, as described above, depending on the application, function, etc. of the metallic glass composite, it is acceptable to not incorporate any of the components included in the third group component (C). The blending ratio of the third group component (C) is adjusted depending on the balance with the first group component (A) and the second group component (B) and the thermal expansion coefficient. For this reason, in the glass material used in the metallic glass composite of the embodiment, when the third group component (C) is lumped together, in the case of a metal substrate made of a body-centered cubic iron material, the blending ratio of the third group component (C) in the glass material is 10 to 30 mass% in total. In the case of a metal substrate made of a face-centered cubic iron material, the blending ratio of the third group component (C) in the glass material is 10 to 20 mass% in total.

[0049] In the glass material used in the metallic glass composite of the embodiment, the main component (D) is the sum of the first group component (A), the second group component (B), and the third group component (C). The proportion of the main component (D) in the glass material is 90 mass% or more. The entire glass material, excluding unavoidable impurities, can be made up of only the main component (D). Furthermore, in consideration of the application and durability of the metallic glass composite, an auxiliary component (E) is further blended with the main component (D).

[0050] The auxiliary component (E) is blended into a glass material composed of the oxide species of the main component (D) described above for the purposes of facilitating thermal spraying, improving the glassy quality of the glass material when melted, and stabilizing the properties of the glassy coating of the sprayed glass portion, as well as enhancing or adding functionality. To achieve a balanced composition, the auxiliary component (E) is contained in the glass material at 0 to 10 mass %. The compositional components included in the auxiliary component (E) are shown below, divided by function.

[0051] CaO improves corrosion resistance, hardness (wear resistance), etc. CaO also increases the melting property of the glass material during thermal spraying and decreases the softening temperature of the glass material during thermal spraying. This increases the adhesion strength of the glass material sprayed onto the surface of the metal substrate. In the presence of BaO, a small amount of CaO improves the transparency of the glass coating of the sprayed glass portion. Note that, although this depends on the blending ratio with other alkaline components, if the amount of CaO is too large, corrosion resistance and hardness decrease and melting property during thermal spraying also deteriorates.

[0052] SrO increases the melting property of the glass material during thermal spraying and lowers the softening temperature of the glass material during thermal spraying. This increases the adhesion strength of the glass material sprayed onto the surface of the metal substrate. Although SrO is not easily volatilized during thermal spraying, adding a large amount of SrO induces crystallization during slow cooling of the sprayed glass part, causing peeling.

[0053] MgO, P ２ O ５ , K. ２ O, V ２ O ５ , MnO ２ , Fe ２ O ３ , Co ３ O ４ , NiO ２ , CuO, MoO ３, SnO ２ , PbO, BiO ２ , Lu ２ O ３ This increases the melting point of the glass material during thermal spraying and lowers its softening temperature. This increases the adhesion strength of the glass material sprayed onto the surface of the metal substrate. However, depending on the amount, this can decrease corrosion resistance, hardness (abrasion resistance), electrical insulation, and voltage resistance, or cause a sudden increase in the viscosity of the glass material during thermal spraying.

[0054] Cr ２ O ３ , ZrO ２ , W.O. ３ increases the hardness (wear resistance) of the glass coating of the thermal sprayed glass portion. ２ Sb improves corrosion resistance, electrical insulation, and voltage resistance. ２ O ３ has the function of reducing and shrinking the number of bubbles in the glass material that is sprayed and adhered to the surface of the metal substrate. ２ and Sb ２ O ３ can suddenly increase the viscosity of the glass when melted.

[0055] Y ２ O ３ , Nb ２ O ５ , Ta ２ O ３ , Bi ２ O ３ , La ２ O ３ , CeO ２ , Pr ６ O １１ , Nd ２ O ３ , Sm ２ O ３ , Gd ２ O ３ improves the electrical insulation and voltage resistance of the sprayed glass formed on the surface of the metal substrate. However, depending on the content, the melting temperature of the glass material increases, reducing its melting property during spraying. It may also cause a sudden increase in the viscosity of the glass material during melting.

[0056] The metallic glass composites 1A, 1B, 1C, and 1D shown in the schematic diagrams (A) to (D) of FIG. 1 are generally produced in the following order: First, a metal substrate to be sprayed is prepared. Then, the surface of the metal substrate is subjected to a blast treatment. During the blast treatment, Al ２ O ３ Fine particles such as alundum (alundum) and SiC (carborundum) are sprayed onto the surface of the metal substrate. The surface of the metal substrate is roughened by sandblasting, which enhances heat conduction to the metal substrate during heating, as described below. Note that the blasting treatment is optional and is selected depending on the shape of the metal substrate and the area to be sprayed.

[0057] The surface temperature of the metal substrate is heated to 200 to 1000°C, preferably 500 to 1000°C, and more preferably 700 to 1000°C. An electric furnace or the like is used for heating. The heating is performed to maintain the molten state of the glass material prior to the thermal spraying described below. If the metal substrate is at room temperature, the adhesion of the molten glass material to the metal substrate will be extremely reduced.

[0058] For thermal spraying, a plasma spraying device such as that described in Patent Document 2 is used. The glass material is a glassy powder (frit) containing the aforementioned compositional components. The glass material is supplied as a powder to the plasma spraying device, where it is instantaneously melted in the presence of a carrier gas, and sprayed onto the surface of a heated metal substrate, where it adheres to the surface. The thickness of the glassy coating on the sprayed glass portion is adjusted by adjusting the amount sprayed onto the surface of the metal substrate and the number of sprays. In the examples described below, argon gas or dry air was used as the carrier gas.

[0059] The thickness of the glass coating on the sprayed glass portion can be set over a wide range, from 10 to 2000 μm. For example, the thickness of the glass coating on a printing roll or the like is set to 1000 to 2000 μm. Furthermore, in the case of an electrode for silent discharge, the thickness of the glass coating is set to 300 to 1500 μm. Furthermore, in the case of a bolt, the thickness of the glass coating is set to 10 to 100 μm. Of course, these thicknesses are merely examples, and the thickness may be increased or decreased taking into account the application, durability, etc.

[0060] After the thermal spraying, the sprayed glass formed on the surface of the metal substrate is slowly cooled or air-cooled. Then, if necessary, the surface is polished, ground, or otherwise smoothed to produce metallic glass composites 1A, 1B, 1C, 1D, etc., as shown in the schematic diagrams (A) to (D) of FIG. 1 .

[0061] In order to maintain a strong bond between the metal substrate and the sprayed glass portion, it is necessary to match the thermal expansion coefficients of the metal substrate and the sprayed glass portion as closely as possible. As mentioned above, both the metal substrate and the sprayed glass portion undergo volumetric shrinkage during cooling after spraying. However, due to differences in expansion coefficients, the degree of volumetric shrinkage differs, resulting in poor adhesion, such as gaps between the metal substrate and the sprayed glass portion or cracks in the sprayed glass portion.

[0062] For the metal substrate of a body-centered cubic iron material, for example, the linear expansion coefficient of SUS409 is 9.9 (×10 ６ / °C), and the linear expansion coefficient of SS400 is 12 (×10 ６ / °C). From this, in order to make the glass material used for the sprayed glass portion correspond to the linear expansion coefficient of the metal substrate made of body-centered cubic iron material, the value of the linear expansion coefficient of the glass material from room temperature to 300°C is set to 9 to 11 (×10 ６ / °C).

[0063] For the metal substrate of a face-centered cubic iron material, for example, the linear expansion coefficient of SUS304 is 17.3 (×10 ６ / °C). From this, in order to make the glass material used for the sprayed glass portion correspond to the linear expansion coefficient of the metal substrate made of face-centered cubic iron material, the value of the linear expansion coefficient of the glass material from room temperature to 300°C is set to 14 to 17 (×10 ６ / °C).

[0064] When adjusting the thermal expansion coefficients of the metal substrate and the sprayed glass portion (glass material), in addition to the adjustment according to the type of metal substrate described above, the difference in the linear expansion coefficients of the metal substrate and the sprayed glass portion (glass material) is adjusted to be as small as possible. Specifically, the difference between the linear expansion coefficient of the glass material and the linear expansion coefficient of the metal substrate is set to be within 15%. Theoretically, it is possible to achieve a perfect match (0% difference) between the linear expansion coefficients of both. However, in the case of a metal substrate with a curved surface or other shape, the contraction force of the sprayed glass portion formed after plasma spraying is utilized, allowing the sprayed glass portion to be more firmly attached to the surface of the metal substrate.

[0065] Examples of metallic glass composites according to the type of metal substrate are as follows: Iron-based materials include conveyor rolls and plywood for construction materials; Stainless steel alloys include water rollers for printing equipment, zinc plating bath rollers, various rolls and rollers used at room temperature, various rolls and rollers for heating furnaces, electrodes for ozone-generating silent dischargers, and electrodes for plasma generation; Nickel alloys include metal setters for firing various sintered bodies; Chromium-molybdenum steel alloys (e.g., SCM435, etc.) include automotive bolts (particularly for fastening dissimilar metals and parts that generate sparks due to friction and static electricity), bolts for fastening various wind power generation parts (particularly bolts for fastening offshore wind power generation), and bolts for general mechanical equipment.

[0066] In the metallic glass composite of the embodiment, as shown in the cross-sectional schematic diagram of Figure 2 (B), a molten solidified portion 40 is formed at a boundary 30 between the metal substrate portion 10 and the sprayed glass portion 20 in the cross section, in which the sprayed glass portion is embedded in the metal substrate portion. The molten solidified portion 40 is formed to a thickness of 0.3 µm or more. Bubbles 21 exist in the sprayed glass portion 20, and residual glass 22 exists within the metal substrate portion 10 of the molten solidified portion 40. The symbol T30 in the figure is a mark indicating a 30% region in the thickness direction of the sprayed glass portion 20 starting from the boundary portion 30.

[0067] A notable phenomenon in the metallic glass composite of the embodiment is that the molten glass material sprayed onto the metal substrate does not simply adhere (deposit) to the surface of the metal substrate. Specifically, in the surface layer portion of the metal substrate (the boundary between the two), the heated metal substrate and the molten glass material are mixed, and some of the molten glass material penetrates into the metal substrate. This was confirmed by observation with a scanning electron microscope (SEM) (see electron microscope photographs from FIG. 3 onwards). As a result, after cooling, a molten solidified portion is formed in which the sprayed glass portion is embedded in the metal substrate.

[0068] In the metallic glass composite of the embodiment, at the boundary between the metal substrate and the sprayed glass portion, the sprayed glass portion not only adheres to the metal substrate but also penetrates moderately, forming a region where both materials are mixed. Therefore, the sprayed glass portion penetrates into the metal substrate, improving the adhesion strength between them compared to the simple adhesion by conventional spraying. Specifically, durability can be confirmed by the ball drop height test described below.

[0069] The reason why a molten solidified portion is formed in the metallic glass composite of the embodiment is thought to be due to the conditions of plasma spraying, in which the glass material is melted and sprayed onto the heated metal substrate. Since the molten glass material itself is at a high temperature, the surface layer of the metal substrate is further heated by its own heating and the heat caused by the molten glass material, and metal melting occurs also in the surface layer of the metal substrate. Then, the molten glass material collides with the surface layer of the metal substrate with the ejection force (velocity, pressure) from the plasma spraying, and since both are in a molten state within a very limited range, they tend to mix with each other, and ultimately a molten solidified portion is thought to be formed.

[0070] In the case of the above-mentioned Patent Document 1 (JP 2013-216977 A), a molten glass material penetrates into the surface of a metal substrate that has been roughened by blasting. In contrast, the metallic glass composite of the embodiment is structurally different in that it forms a molten solidified portion.

[0071] The electron microscope photographs in Figure 3 and subsequent figures are cross-sections of prototype metallic glass composites, and measurements based on the photographs at increased magnification (B) in each figure confirmed that the molten solidified portion had a thickness of 0.3 μm or more. The upper limit of the molten solidified portion cannot exceed the overall thickness of the sprayed glass portion. Therefore, the upper limit of the molten solidified portion is considered to be approximately 1 μm or less in thickness. As can be seen from each photograph, in the metallic glass composite of the embodiment, the boundary portion is the interface where the sprayed glass portion contacts the metal substrate portion. The molten solidified portion is a portion where the glass material is trapped and scattered within the metal substrate portion, and is the depth from the boundary between the metal substrate portion and the sprayed glass portion to the range where the trapped glass material is present.

[0072] The above explanations disclose the relationship between the composition and thermal expansion coefficient of both the sprayed glass portion (glass material) and the metal substrate, as well as the characteristics of the molten and solidified portion that occurs at the boundary. In addition, a specification is required after the sprayed glass portion is formed on the surface of the metal substrate. Specifically, it is necessary to control the amount of bubbles present in the sprayed glass portion. Therefore, the area ratio of bubbles 1 μm or larger in the cross section of the sprayed glass portion in the thickness direction of the finished metallic glass composite is suppressed to less than 40%. To measure the bubbles, the metallic glass composite is cut in the thickness direction of the sprayed glass portion to expose the cut surface. The cut surface is then enlarged using a scanning electron microscope (SEM), and the area of ​​bubbles 1 μm or larger in diameter is determined on the exposed cut surface. The total area of ​​bubbles 1 μm or larger in diameter is then calculated. The area ratio of bubbles 1 μm or larger is calculated as the total area of ​​bubbles in the area of ​​the cut surface of the sprayed glass portion. That is, the area ratio of bubbles of 1 μm or more is calculated as follows: "area ratio (%) of bubbles of 1 μm or more" = {(total area of ​​bubbles of 1 μm or more on the cut surface) / (total area of ​​the cut surface)}×100.

[0073] When the amount of bubbles increases in the sprayed glass portion of a metallic glass composite, the sprayed glass portion becomes more sponge-like, losing its density and reducing its structural strength. As shown in the ball drop height test described below, the higher the area ratio of bubbles in the cross section, the lower the impact strength. Therefore, since this is an index that directly affects the durability of the metallic glass composite, the area ratio of bubbles 1 μm or larger in the cross section in the thickness direction of the sprayed glass portion is less than 40%, preferably 30% or less, and more preferably 20% or less.

[0074] Furthermore, when the metallic glass composite is expected to be used as an electrode, a high bubble area ratio makes the sprayed glass portion more susceptible to dielectric breakdown and other problems when current is applied. This can cause damage to devices incorporating the metallic glass composite. Therefore, it is important to minimize the bubble area ratio. As explained in the glass material components section, the second group component (B) is prone to volatilization when the glass material is melted by heating during spraying, and gasification at this time generates bubbles. Furthermore, during spraying, the molten glass material is instantaneously applied to the surface of the metal substrate and adheres to the surface. Bubbles generated in the molten glass material cannot move, and remain trapped in the sprayed glass portion as it cools, remaining in the sprayed glass portion.

[0075] The blending ratios of the first group component (A), the second group component (B), and the third group component (C) in the glass material are necessary for adjusting the thermal expansion coefficient of the metal substrate and controlling the durability of the glass. Therefore, the second group component (B) is blended regardless of gasification. As can be seen from this, the composition of the glass material of the embodiment is established in a balance that adjusts the thermal expansion coefficient of the metal substrate while suppressing residual bubbles for durability reasons.

[0076] In the metallic glass composite of the embodiment, the basic presence region and area ratio are further specified in detail. Specifically, at the boundary between the metal substrate portion and the sprayed glass portion in a longitudinal cross section of the metallic glass composite, the area ratio of bubbles 1 μm or larger that exist within a region within 30% of the thickness of the sprayed glass portion from the boundary is desirably suppressed to 50% or less. Furthermore, the thickness of the sprayed glass portion is desirably in the range of 10 to 100 μm, and the area ratio of bubbles 1 μm or larger in the cross section in the thickness direction of the sprayed glass portion is desirably less than 10% in the sprayed glass portion.

[0077] As mentioned above, when spraying a glass material, the compositional components volatilize and gasify due to the heat of the spraying. Then, because the molten glass material is sprayed before the volatilized gases can diffuse, they are left behind as bubbles. In particular, in metallic glass composites, the deep regions of the sprayed glass portion, in other words, the regions close to the metal substrate, tend to inevitably have many bubbles. Furthermore, to increase the adhesive strength between the sprayed glass portion and the metal substrate, it is desirable for the sprayed glass portion to be dense, i.e., to have as few bubbles as possible.

[0078] Therefore, in order to make it possible to grasp the shape of the sprayed glass portion, the area ratio of bubbles of 1 μm or more is suppressed to 50% or less, preferably 40% or less, in the region starting from the boundary and extending up to 30% (including within 30%) of the thickness of the sprayed glass portion. By suppressing the amount of bubbles near the boundary of the sprayed glass portion, the density of the sprayed glass portion near the boundary increases, making it easier to increase its strength.

[0079] Furthermore, the thickness of the sprayed glass portion of a metallic glass composite can be adjusted by changing the amount of spraying depending on the application. However, a thicker sprayed glass portion increases the glass content, which may lead to cracks after cooling and reduced durability during use. In particular, for purposes such as corrosion protection and insulation, the thinner the thickness, the better. For this reason, the thickness of the sprayed glass portion is usually set to a range of 10 to 100 μm.

[0080] In a sprayed glass portion of this thickness, the presence of bubbles directly contributes to a decrease in performance such as durability and insulation, so it is desirable to reduce the number of bubbles even further than the above-mentioned conditions. Therefore, the area ratio of bubbles of 1 μm or more in the sprayed glass portion (entire cross section) is suppressed to less than 10%, preferably less than 7%.

[0081] [Types of Metallic Substrates] In producing the metallic glass composite, the following three types of metal substrate plates (100 mm x 30 mm, thickness 1.2 mm) were used. SUS409, SUS430, and SS400 were used as metal substrates made of body-centered cubic iron materials. SUS304 was used as metal substrates made of face-centered cubic iron materials. For reference, the metal composition (mass%) and linear expansion coefficient (×10 －６ / °C) are shown in Table 1. Since each metal in the table is an iron-based alloy, Fe is shown as the balance.

[0082]

[0083] [Treatment of Metal Substrate] The plate-shaped metal substrates listed in Table 1 were sandblasted with #60 or #80 alundum, and the surfaces were air-washed to remove dust. Prior to thermal spraying, the plates were heated to approximately 700 to 1000°C in an electric furnace, and thermal spraying was carried out under the conditions described below before the temperature was lowered.

[0084] [Composition of Glass Material] Each component was blended according to the composition shown in Table 2 below to prepare glass materials of prototypes 1 to 16, which were then pulverized into frit (powder). The frit was classified to a desired average particle size. In the table, each component is expressed as mass % of the entire glass material. For ease of understanding, the total of the second group components (B) and the total of the third group components (C) in the entire glass material are also shown. In addition, the linear expansion coefficient (α) (unit: × 10) of each prototype was －６ / ℃).

[0085]

[0086] [Thermal Spraying Apparatus and Thermal Spraying Conditions] For plasma spraying, a thermal spraying apparatus manufactured by Praxair Technology, Inc., product name "Model SG-100 Plasma Spray Gun" was used. In addition, the devices used for controlling the supply of electricity, cooling water, gas, and spray material were Praxair's product name "Model 3710 Plasma Control Console," the glass material supply device was Praxair's product name "Model 1264 Powder Feeder," the power supply device was Praxair's product name "Model PS-1000 Plasma Power Source," and the high-frequency generator was Praxair's product name "Model HF-2200."

[0087] The same conditions were used for the glass frits of prototypes 1 to 16. However, the scanning speed of the plate-shaped metal substrate during spraying was increased or decreased to adjust the amount of deposition associated with spraying onto the surface. Spraying conditions: Voltage: 30 to 50 V, Current: 700 to 1000 A, Heating temperature of metal substrate: 700 to 1000°C

[0088] For each thermal spraying condition, if the lower limit is exceeded, the effect of insufficient heat is so great that the glass material does not melt on the surface of the metal substrate, making it impossible to ensure adhesion.If the upper limit is exceeded, the melting of the metal substrate becomes too intense, causing deformation of the metal substrate itself.

[0089] The raw material supply conditions were the following gas species and flow rates. The raw material carrier gas was dry air or argon. When the flow rate was Fa (NL / min) and the raw material supply rate was Fb (g / min), "Fb / Fa" was controlled to 0.4 or less. If "Fb / Fa" exceeds 0.4, melting of the base material becomes difficult even if the above-mentioned thermal spraying conditions are met.

[0090] [Characteristics of Metallic Glass Composites] Prototypes G1 to G21 were fabricated as metallic glass composites with a metal substrate made of body-centered cubic iron material, and prototypes H1 to H8 were fabricated as metallic glass composites with a metal substrate made of face-centered cubic iron material. The results for prototypes G1 to G21 are shown in Table 3, and the results for prototypes H1 to H8 are shown in Table 4.

[0091] Tables 3 and 4 list, in order, the prototype number, the type of glass material disclosed in Table 2, the type of metal substrate, the heating temperature (°C) of the metal substrate, the amount of current (A) during spraying, the thickness (µm) of the sprayed glass portion of the final metallic glass composite, the area ratio (%) of bubbles 1 µm or larger in size to the entire sprayed glass portion, the area ratio (%) of bubbles 1 µm or larger that exist in a region within 30% of the thickness of the sprayed glass portion starting from the boundary portion, the thickness (µm) of the molten and solidified portion, the maximum diameter (µm) of bubbles present in the sprayed glass portion, the falling ball height (cm), and the dielectric strength test (MV / m).

[0092] To observe and measure the thickness and bubbles, each metallic glass composite was cut longitudinally and observed using a scanning electron microscope (SEM). Figure 3 shows electron microscope photographs of prototype G1, Figure 4 shows prototype G2, Figure 5 shows prototype G6, Figure 6 shows prototype G11, Figure 7 shows prototype G13, Figure 8 shows prototype G19, and Figure 9 shows prototype H5. (A) in each figure is a 100x magnified photograph, and (B) in each figure is a 1000x magnified photograph.

[0093] The ball drop height was evaluated by dropping a 150 g steel ball from directly above onto the sprayed glass portion (exposed glass surface) of each metallic glass composite. The height (vertical length from the sprayed glass portion to the steel ball) at which the impact of the dropped steel ball caused visible defects such as cracks, fissures, or chips in the sprayed glass portion was recorded as the ball drop height for that sample. The plot graph (scatter diagram) in Figure 10 shows the relationship between the total bubble area fraction (%) in the sprayed glass portion of each metallic glass composite and the ball drop height (cm).

[0094] The dielectric strength test was conducted in accordance with the test method of JIS C 2110 (2016) (IEC 60243-1:2013), and the metallic glass composites of each prototype were measured. The plot graph (scatter diagram) in Figure 11 shows the relationship between the bubble area ratio (%) at the boundary of the sprayed glass portion of the metallic glass composite of each prototype and the dielectric strength (MV / m). For the dielectric strength test, a Nippon Technate HP-5110DS electric condenser was used, and the presence or absence of leakage was evaluated by applying 10 kV for 1 minute.

[0095] For the metallic glass composites of Samples G1 to G19 in Table 3, the moving speed of the thermal spraying device was 31 mm / sec, Samples G1 to G18 were sprayed five times on the metal substrate, and Sample G19 was sprayed once. Sample G20 was sprayed once at a moving speed of 52 mm / sec, and Sample G21 was sprayed once at a moving speed of 125 mm / sec.

[0096] For the metallic glass composites of Samples H1 to H8 in Table 4, the moving speed of the thermal spraying device was set to 31 mm / sec, and the metal substrate was thermally sprayed five times.

[0097] For the metallic glass composites of prototypes H9 to H16 in Table 5, the movement speed of the spraying device was 125 mm / sec and the metal substrate was sprayed once; for the metallic glass composites of prototypes H17 to H21, the movement speed of the spraying device was 52 mm / sec and the metal substrate was sprayed once; and for the metallic glass composites of prototypes H22 to H24, the movement speed of the spraying device was 31 mm / sec and the metal substrate was sprayed five times.

[0098]

[0099]

[0100]

[0101] [Results and Discussion] As shown in Table 3, the metallic glass composite of Prototype Example G6 used the glass material of Prototype Example 4. Prototype Example 4 had a high proportion of the second group component (B), a volatile component (32 mass % in total). As a result, the bubble area ratio increased. The increased voids due to the increased number of bubbles worsened the falling ball height. In contrast, the metallic glass composite of Prototype Example G5 used the glass material of Prototype Example 3. The proportion of the second group component (B) in the glass material of Prototype Example 3 was 29 mass % in total. As a result, a decrease in the total bubble area ratio of Prototype Example G5 was confirmed, and an increase in the falling ball height was also evident. Therefore, for a metal substrate portion made of a body-centered cubic iron material found in SUS409, the upper limit of the proportion of the second group component (B) is estimated to be 30 mass %.

[0102] The metallic glass composites of prototypes G19 to G21 are examples in which the glass film thickness of the sprayed glass portion was thinned to 100 μm or less. For prototypes G19 to G21, the glass materials of prototypes 1 and 16, which have a low proportion of the second group component (B), were used. This is thought to have suppressed the amount of volatilization during spraying and reduced the generation of bubbles. The results of the falling ball height confirmed the formation of an extremely strong sprayed glass portion.

[0103] When producing each prototype metallic glass composite, the spraying environment using a plasma spraying device was in a temperature range sufficient to melt the outermost surface of the metal substrate, which served as the base for the spraying. Therefore, the thermal influence of the spraying process made the composition of the glass material more likely to volatilize. In particular, the linear expansion coefficient of body-centered cubic iron materials is lower than that of metals made of face-centered cubic iron materials, so it is more important to control the thermal expansion coefficient (linear expansion coefficient) and the upper limit of the easily volatilized second group component (B). Therefore, based on the results of the prototypes, the blending ratio of the second group component (B) in the glass material was 10 to 30 mass%, preferably 20 to 30 mass%.

[0104] The metallic glass composites of prototypes H1 to H24 are examples of metal substrates (SUS304) made of face-centered cubic iron material. Since face-centered cubic iron material has a larger linear expansion coefficient than body-centered cubic iron material, the restrictions on the blending ratio of the second group component (B) are relaxed. Furthermore, the amount of bubbles is generally small, and the falling ball height is good. Therefore, the blending ratio of the second group component (B) in the glass material is 25 to 35 mass%.

[0105] When preparing the glass material of the prototype, the SiO ２ If the content of SiO exceeds 70% by mass, the viscosity of the molten glass material becomes excessive during thermal spraying, resulting in significant residual bubbles. If the content of SiO is less than 35% by mass, it becomes difficult to adjust the linear expansion coefficient. Therefore, in the case of a body-centered cubic iron material, the proportion of the first group component (A) in the glass material is ２ For the same reason, in the case of a face-centered cubic iron material, the SiO content of the first group component (A) in the glass material is 35 to 70 mass %. ２ is 50 to 60% by mass.

[0106] The third group component (C) is a component that affects the viscosity of the molten glass material. From the results of the glass material and metallic glass composite of each prototype, in the case of a body-centered cubic iron material, the total amount of the third group component (C) in the glass material is 10 to 30 mass %, and in the case of a face-centered cubic iron material, the total amount of the first group component (A), SiO ２ is 10 to 20% by mass.

[0107] Considering the results of the falling ball height and dielectric strength of the metallic glass composites of prototypes G1 to G19 and the metallic glass composites of prototypes H1 to G24, the area ratio of bubbles 1 μm or larger in the cross section in the thickness direction of the sprayed glass portion is less than 40%, preferably 30% or less. In addition, the area ratio of bubbles 1 μm or larger present in a region within 30% of the thickness direction of the sprayed glass portion from the boundary is also preferably 50% or less. Furthermore, in the metallic glass composites of prototypes G19 to G21 where the thickness of the sprayed glass portion is 100 μm or less, the area ratio of bubbles 1 μm or larger present in the thickness direction of the sprayed glass portion can be extremely reduced to 10% or less, resulting in improved performance in the falling ball height and dielectric strength.

[0108] The relationship between the total bubble area ratio (%) and the falling ball height (cm) is shown as a plot graph in Figure 10. As the total bubble area ratio increases, the value of the falling ball height tends to decrease. This indicates a decrease in the strength of the sprayed glass portion due to the increase in bubbles. The relationship between the bubble area ratio (%) at the boundary and the dielectric strength (MV / m) is shown as a plot graph in Figure 11. Dielectric strength is maintained up to a bubble area ratio of 40% at the boundary. However, once the bubble area ratio at the boundary exceeds 40%, the decrease in dielectric strength becomes noticeable. From this trend, the range of the bubble area ratio mentioned above is determined.

[0109] 1A, 1B, 1C, 1D Metallic glass composite 10, 11, 12, 13, 14 Metal substrate portion 20 Sprayed glass portion 21 Air bubble 22 Residual glass 30 Boundary portion 40 Melted and solidified portion T30 30% region in the thickness direction of the sprayed glass portion

Claims

1. A metal substrate made of a body-centered cubic iron material and a sprayed glass portion formed on the metal substrate with a film thickness of 10 to 2000 μm, the glass material forming the sprayed glass portion comprising, as a first group component (A), SiO ２ : 35 to 70 mass %, and as the second group component (B), ２ O ３ : 9 to 15% by mass, Li ２ O: 5 to 9 mass% and Na ２ O: 4 to 10 mass%, the total amount being 18 to 30 mass%, and as a third group component (C), BaO: 0 to 15 mass%, TiO ２ : 2 to 15 mass% and Al ２ O ３ : 0 to 8 mass % and ZnO: 0 to 15 mass % in total, the total of the first group component (A), the second group component (B), and the third group component (A) constitute a main component (D) of 90 mass % or more, and the linear expansion coefficient of the glass material at room temperature to 300° C. is 9 to 11 (×10 ６ / °C), and an area ratio of bubbles having a size of 1 µm or more in a cross section in a thickness direction of the thermal sprayed glass portion is less than 40%.

2. A glass material for forming the sprayed glass portion, which has a metal substrate made of a face-centered cubic iron material and a film thickness of 10 to 2000 μm, is contained as a first group component (A) in the glass material for forming the sprayed glass portion. ２ 50 to 60% by mass, and the second group component (B) is ２ O ３ : 2 to 8 mass% and Li ２ O: 8 to 15 mass% and Na ２ O: 8 to 20 mass%, the total amount being 25 to 35 mass%, and as the third group component (C), BaO: 3 to 12 mass%, TiO ２ : 4 to 15 mass% and Al ２ O ３ : 0 to 5 mass % and ZnO: 0 to 5 mass % in total, the total of the first group component (A), the second group component (B), and the third group component (A) constitute a main component (D) of 90 mass % or more, and the linear expansion coefficient of the glass material at room temperature to 300°C is 14 to 17 (×10 ６ / °C), and an area ratio of bubbles having a size of 1 µm or more in a cross section in a thickness direction of the thermal sprayed glass portion is less than 40%.

3. The metallic glass composite according to claim 1 or 2, wherein the difference between the linear expansion coefficient of the glass material and the linear expansion coefficient of the metal substrate is within 15%.

4. The metallic glass composite according to claim 1 or 2, wherein the metallic glass composite has a molten and solidified portion in which the sprayed glass portion is embedded in the metallic substrate portion at the boundary between the metallic substrate portion and the sprayed glass portion in the cross section, and the molten and solidified portion has a thickness of 0.3 μm or more.

5. A metal glass composite as described in claim 1 or 2, wherein the sprayed glass portion has an area ratio of 1 μm or larger bubbles that exist within an area of ​​30% of the thickness of the sprayed glass portion starting from the boundary between the metal substrate portion and the sprayed glass portion in the cross section, of 50% or less.

6. The metallic glass composite according to claim 1 or 2, wherein the thickness of the sprayed glass portion is 10 to 100 μm, and the area ratio of bubbles of 1 μm or more in a cross section in the thickness direction of the sprayed glass portion is less than 10%.

7. The components of the glass material other than the main component (D) are auxiliary components (E), and the auxiliary components (E) are CaO, SrO, MgO, P ２ O ５ , K ２ O.V. ２ O ５ , Cr ２ O ３ , MnO ２ , Fe ２ O ３ , Co ３ O ４ , NiO ２ , CuO, Y ２ O ３ , ZrO ２ , Nb ２ O ２ , MoO ３ , SnO ２ , Sb ２ O ３ , W.O. ３ , PbO, Bi ２ O ３ , La ２ O ３ , CeO ２ , P ６ O １１ , Nd ２ O ３ , Sm ２ O ３ , Gd ２ O ３ 3. The metallic glass composite according to claim 1, wherein the metallic glass composite is made of one or more of the following:

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