Cold spray coating, cold spray coating as well as preparation method and application of cold spray coating

Abstract

The invention provides a cold spray coating, a cold spray coating as well as a preparation method and application of the cold spray coating. The cold spraying coating is prepared from the following components in parts by weight: 20 to 50 parts of glass powder A, 5 to 30 parts of glass powder B, 10 to 70 parts of high-temperature-resistant filler and 20 to 60 parts of solvent. According to the coating with specific components, a coating can be prepared through a cold spraying technology, the porosity of the coating can be reduced, the compactness of the coating can be improved, when the coating is applied to the surfaces of alloys such as titanium alloys, high-temperature alloys and stainless steel, the effect of protecting the alloys for a long time can be achieved, and the service life of the alloys can be remarkably prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy protection, and in particular to a cold spray paint, a cold spray coating, and a preparation method and application thereof. Background Art

[0002] As the core component of the aircraft, the overall performance of aircraft engines is constantly improving, and the engine thrust is getting bigger and bigger. As a result, the problems of high-temperature fuel gas thermal corrosion and thermal fatigue of the hot end components of the engine, which are mainly made of high-temperature alloys, will become more and more serious. While higher requirements are placed on the performance of high-temperature alloys, higher requirements are also placed on the overall protection of the surface of high-temperature alloys.

[0003] The surface of the hot end parts of aircraft engines, which are mainly made of high-temperature alloys, usually needs to be coated and enameled with high-temperature resistant ceramic coatings to improve their high temperature resistance, high-speed airflow erosion resistance and service life. At present, the long-term protection of hot end parts of foreign engines mainly adopts the method of thermal spraying oxides, such as: YSZ, ZrO 2 、Al 2 O 3 Cr 2 O 3 The coating is directly applied on the surface of the parts by thermal spraying, which is characterized by high operating temperature, but its porosity is 1-8%. When the parts are working, corrosive gases or liquids are very likely to penetrate into the part matrix through the coating, affecting the working life of the parts, so it is necessary to add sealing treatment and other processes. Moreover, the raw materials of the coating of existing products are mostly pure high-temperature ceramic powders, which are difficult to sinter into dense ceramic coatings only by high-temperature sintering. They are not suitable for cold spraying. The ceramic powders must be heated to a molten state by special equipment and then sprayed onto the surface of the metal substrate. The coating cost is high, the investment in thermal spraying equipment is large, and the overall economic efficiency is poor. Summary of the invention

[0004] The main purpose of the present invention is to provide a cold spray paint, a cold spray coating and a preparation method and application thereof, so as to solve the problems in the prior art that the cold spray coating coated by the thermal spray method has a high porosity resulting in a poor protective effect of the cold spray coating, as well as a complex preparation process, high cost, large equipment investment and poor overall economic efficiency.

[0005] In order to achieve the above object, according to one aspect of the present invention, a cold spray coating is provided, which comprises, by weight, 20 to 50 parts of glass powder A, 5 to 30 parts of glass powder B, 10 to 70 parts of high temperature resistant filler and 20 to 60 parts of solvent; wherein the glass powder A comprises 30 to 50 parts of SiO 2 , 20 to 40 parts of BaO, 1 to 15 parts of Al 2 O 3 1 to 15 parts of B 2 O3 , 0 to 10 parts of Na 2 O, 5-20 parts of TiO 2 and 1 to 10 parts of CaO; glass powder B includes 5 to 30 parts of SiO 2 , 1 to 20 parts of Al 2 O 3 , 1 to 20 parts of BaO, 5 to 20 parts of B 2 O 3 , 5 to 20 parts of Na 2 O, 5 to 20 parts K 2 O, 1 to 10 parts of MgO and 1 to 10 parts of CaO; high temperature resistant fillers include Al 2 O 3 、ZrO 2 、SiO 2 Cr 2 O 3 Cr 2 C 3 and bentonite.

[0006] Further, the cold spray coating comprises, by weight, 30 to 40 parts of glass powder A, 10 to 20 parts of glass powder B, 18 to 61 parts of high temperature resistant filler and 30 to 50 parts of solvent; preferably, by weight percentage, the sum of glass powder A and glass powder B accounts for 30 to 40% of the cold spray coating; and / or, glass powder A comprises 35 to 45 parts of SiO 2 , 25-35 parts of BaO, 5-10 parts of Al 2 O 3 , 5 to 10 portions of B 2 O 3 , 0 to 5 parts of Na 2 O, 10-15 parts of TiO 2 and 1 to 5 parts of CaO; and / or, the glass powder B includes 10 to 20 parts of SiO 2 , 5 to 10 parts of Al 2 O 3 , 5-10 parts of BaO, 8-15 parts of B 2 O 3 , 10-15 parts of Na 2 O, 7 to 12 parts K 2 O, 1 to 5 parts of MgO and 2 to 6 parts of CaO.

[0007] Furthermore, the high temperature resistant filler includes 3 to 10 parts by weight of Al 2 O 3 , 2 to 10 parts of ZrO 2 , 2 to 15 parts of SiO 2 , 5 to 10 parts of Cr 2O 3 , 3 to 8 parts of Cr 2 C 3 and 3 to 8 parts of bentonite; and / or, the solvent comprises one or more of water, isopropanol and ethanol.

[0008] Furthermore, in the cold spray coating, the particle size of the solid component is 200-400 mesh; and / or, the softening temperature of the cold spray coating is 1000-1200°C; and / or, the glass transition temperature of the cold spray coating is 800-1000°C.

[0009] According to another aspect of the present invention, a cold spray coating is provided, which is obtained by cold spraying and sintering the above-mentioned cold spray coating.

[0010] Further, the porosity of the cold spray coating is ≤0.1%; and / or the expansion coefficient of the cold spray coating is 70×10 -7 ~100×10 -7 / ℃; and / or, the surface roughness of the cold sprayed coating is 0.1-0.5Ra.

[0011] According to another aspect of the present invention, a method for preparing the above-mentioned cold spray coating is provided, in which glass powder A, glass powder B, high temperature resistant filler and solvent are mixed according to a component ratio, the obtained cold spray coating is cold sprayed on the surface of a metal substrate, and dried and sintered in sequence to obtain a cold spray coating.

[0012] Furthermore, the mixing method is ball milling and / or stirring; and / or, before cold spraying, the step of aging the cold spray coating is also included; preferably, the aging time is 10 to 20 days, and the temperature is 20 to 40°C; and / or, the metal substrate includes one or more of titanium alloy, high-temperature alloy and stainless steel; and / or, before cold spraying, the step of controlling the surface temperature of the metal substrate to 0 to 40°C is also included.

[0013] Furthermore, the sintering temperature is 1000-1250°C; and / or the loading amount of the cold spray coating on the substrate surface is 0.15-0.35 kg / m 2 ; and / or, the thickness of the cold spray coating is 0.04 to 0.08 mm.

[0014] According to another aspect of the present invention, there is provided application of the cold spray coating in the field of alloy protection.

[0015] The coating of the specific composition of the present invention can be prepared by cold spraying technology, and the obtained coating has small porosity and high density. When used on the surface of titanium alloy, high temperature alloy, stainless steel and other alloys, it can effectively inhibit the corrosion and oxidation of the substrate by high temperature, salt spray, wet heat, high-speed airflow scouring, etc., and play a role in long-term protection of the alloy, thereby significantly extending the service life of the alloy. Moreover, the cold spray coating of the present invention can be prepared using a simple process, especially a simple spraying process, with relatively low cost, small equipment investment, and good comprehensive economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A surface photograph of the cold sprayed coating during the sintering process of Example 1 of the present invention is shown;

[0018] Figure 2 A surface photograph of the cold sprayed coating after natural cooling according to Example 1 of the present invention is shown; and

[0019] Figure 3 A surface photograph of the cold sprayed coating after natural cooling according to Example 2 of the present invention is shown. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] Terminology explanation:

[0022] Thermal spraying: Powder is heated to a molten or semi-molten state by flame, arc or plasma, and sprayed onto the surface of the substrate by air flow or flame. Millions of particles are deposited together to form a coating.

[0023] Cold spray coating: A solid-state deposition technique in which the spray material is ejected onto the substrate surface. The particles undergo plastic deformation due to the extremely high kinetic energy when impacting the substrate and adhere firmly to the substrate.

[0024] High temperature alloy: High temperature alloys are divided into two types: nickel-based high temperature alloys and cobalt-based high temperature alloys.

[0025] As described in the background of the present invention, the prior art has the problem that the cold spray coating coated by the thermal spraying method has a high porosity, resulting in a poor protective effect of the cold spray coating, as well as a complex preparation process, high cost, large equipment investment, and poor overall economic efficiency. In order to solve the above problems, in a typical embodiment of the present invention, a cold spray coating is provided, which includes, by weight, 20 to 50 parts of glass powder A, 5 to 30 parts of glass powder B, 10 to 70 parts of high temperature resistant filler and 20 to 60 parts of solvent; wherein the glass powder A includes 30 to 50 parts of SiO 2 , 20 to 40 parts of BaO, 1 to 15 parts of Al 2 O 3 1 to 15 parts of B 2 O 3 , 0 to 10 parts of Na 2 O, 5-20 parts of TiO 2 and 1 to 10 parts of CaO; glass powder B includes 5 to 30 parts of SiO 2 , 1 to 20 parts of Al 2 O 3 , 1 to 20 parts of BaO, 5 to 20 parts of B 2 O 3 , 5 to 20 parts of Na 2 O, 5 to 20 parts K 2 O, 1 to 10 parts of MgO and 1 to 10 parts of CaO; high temperature resistant fillers include Al 2 O 3 、ZrO 2 、SiO 2 Cr 2 O 3 Cr 2 C 3 and bentonite.

[0026] In the prior art, the long-term protection of foreign engine hot end components mainly adopts the method of thermal spraying oxides, such as YSZ, ZrO 2 、Al 2 O 3 Cr 2 O 3etc., directly coating it on the surface of parts by thermal spraying, which is characterized by high operating temperature, but its porosity is 1-8%, and corrosive gas or liquid is very likely to penetrate into the part matrix through the coating when the part is working, affecting the working life of the part, so it is necessary to add sealing treatment and other processes. Moreover, most of the raw materials for coatings of existing products are pure high-temperature ceramic powders, which are difficult to sinter into dense ceramic coatings only by high-temperature sintering, and are not suitable for cold spraying. Special equipment is required to heat the ceramic powder to a molten state first, and then spray it onto the surface of the metal substrate. The coating cost is high, the investment in thermal spraying equipment is large, and the overall economic efficiency is poor.

[0027] The cold spray coating of the present application includes glass powder A, glass powder B, high temperature resistant filler and solvent. Glass powder has a relatively low softening temperature, so the cold spray coating can be sprayed at room temperature, and then sintered to form a cold spray coating on the surface of the metal substrate. The softening temperature of the glass powder B with specific components of the present application is relatively low. After the cold spray coating enters the furnace, it can soften quickly and form a dense film layer, which effectively isolates the corrosion of oxygen and other gases to the substrate, so that the substrate is not oxidized during the sintering process; on the other hand, glass powder B has a large expansion coefficient, which makes the expansion coefficient of the cold spray coating similar to and slightly lower than that of the substrate metal, and there is a certain tensile stress and compressive stress between the cold spray coating and the metal. Since the compressive strength of the cold spray coating with specific components of the present application is more than 10 times the tensile strength, about 80 to 150 kg / mm 2 , can withstand large compressive stress, is not prone to breakage, and the cold spray coating can be densely present on the metal surface. Secondly, the glass powder A of the specific composition of the present application has a high softening temperature and high high-temperature viscosity. During the high-temperature sintering process, the addition of glass powder A can effectively increase the sintering temperature of the cold spray coating, thereby facilitating the formation of a dense cold spray coating.

[0028] In addition, the addition of specific high temperature resistant fillers can effectively improve the high temperature resistance and high temperature stability of the cold spray coating. 2 O 3 and Cr 2 C 3 The mutual synergy can effectively enhance the bonding strength between the cold spray coating and the base metal at high temperature, and is conducive to the formation of a dense cold spray coating.

[0029] Moreover, the present application also specifically limits the content range of glass powder A, glass powder B, high temperature resistant filler and solvent in the cold spray coating. Within this range, the components can cooperate with each other, and a cold spray coating can be obtained through cold spraying and sintering. Moreover, the cold spray coating has low porosity, high bonding strength with the substrate, good density, good protective effect on the substrate, and good high temperature resistance and high temperature stability.

[0030] It should be noted that if the content of glass powder A in the cold spray coating is less than 20 parts, it is easy to cause the high temperature resistance of the cold spray coating to deteriorate. If the content of glass powder A is higher than 50 parts, it is difficult to form a dense cold spray coating. If the content of glass powder B is too high, the overall temperature resistance of the cold spray coating may be reduced. If the content of glass powder B is too low, the cold spray coating is difficult to sinter densely, and the base metal is prone to oxidation during the sintering process. If the content of high temperature resistant filler is too high, it is easy to cause the viscosity of the coating to be too high, which is not conducive to the coating operation, and may cause the adhesion of the coating to be weak, which is easy to cause the coating to peel off and crack, and the cost is high. If its content is too low, it is easy to cause the high temperature resistance and high temperature stability of the cold spray coating to deteriorate. If the content of the solvent is too high, the coating is easy to boil and produce too many bubbles after being coated on the surface of the substrate, which affects the compactness of the coating and is also easy to cause the coating to have poor compactness. If its content is too low, it is easy to cause the fluidity of the coating to deteriorate, and it will also affect the compactness and uniformity of the coating.

[0031] In summary, the coating with specific components of the present application can be prepared by cold spraying technology, which is beneficial to reduce the porosity of the coating and improve the density of the coating. When used on the surface of alloys such as titanium alloys, high-temperature alloys, and stainless steel, it can effectively inhibit the corrosion and oxidation of the substrate caused by high temperature, salt spray, damp heat, and high-speed airflow erosion, and play a role in long-term protection of the alloy, thereby significantly extending the service life of the alloy.

[0032] In order to make the cold spray coating more suitable for the cold spray process and make the cold spray coating obtained by sintering more dense, in a preferred embodiment, the cold spray coating includes 30 to 40 parts of glass powder A, 10 to 20 parts of glass powder B, 18 to 61 parts of high temperature resistant filler and 30 to 50 parts of solvent by weight; preferably, the sum of glass powder A and glass powder B accounts for 30 to 40% of the cold spray coating by weight percentage; and / or, glass powder A includes 35 to 45 parts of SiO 2 , 25-35 parts of BaO, 5-10 parts of Al 2 O 3 , 5 to 10 portions of B 2 O 3 , 0 to 5 parts of Na 2 O, 10-15 parts of TiO 2 and 1 to 5 parts of CaO; and / or, the glass powder B includes 10 to 20 parts of SiO 2 , 5 to 10 parts of Al 2 O 3 , 5-10 parts of BaO, 8-15 parts of B 2 O 3 , 10-15 parts of Na 2 O, 7 to 12 parts K 2 O, 1 to 5 parts of MgO and 2 to 6 parts of CaO.

[0033] In order to further improve the high temperature resistance and high temperature stability of the cold spray coating, in a preferred embodiment, the high temperature resistant filler includes 3 to 10 parts by weight of Al 2 O 3 , 2 to 10 parts of ZrO 2 , 2 to 15 parts of SiO 2 , 5 to 10 parts of Cr 2 O 3 , 3 to 8 parts of Cr 2 C 3 and 3 to 8 parts of bentonite; and / or, the solvent includes one or more of water, isopropanol and ethanol. Under the above conditions, the solubility between the solid components is better, and the solvent is more easily volatilized after cold spraying.

[0034] In a preferred embodiment, in the cold spray coating, the particle size of the solid component is 200-400 mesh. If the particle size of the solid component is too large, it may be detrimental to the subsequent mixing step; if the particle size is too small, the production cost of the powder will increase. In a preferred embodiment, the softening temperature of the cold spray coating is 1000-1200°C; and / or the glass transition temperature of the cold spray coating is 800-1000°C. Under the above conditions, it is easier to prepare a dense cold spray coating.

[0035] In another typical embodiment of the present invention, a cold spray coating is also provided, which is obtained by cold spraying and sintering the above-mentioned cold spray coating. The coating of the present application is obtained by cold spraying the coating and sintering, and is a high-temperature resistant ceramic coating. The coating has low porosity, good density, and high temperature resistance. When the coating of the present application is used on the surface of the alloy, it can effectively inhibit the corrosion and oxidation of the substrate by high temperature, salt spray, humidity, high-speed airflow scouring, etc., and play a role in long-term protection of the alloy, thereby significantly extending the service life of the substrate, and the coating can still be repaired by re-coating and re-sintering after it reaches its service life and falls off. Moreover, the preparation process of the coating of the present application is simple, especially the spraying process is simple, the cost is relatively low, and it is not limited by the site and environment. In addition, the coating thickness is controllable during the preparation process, and a multi-component ceramic coating can be prepared, the equipment investment is small, and the overall economy is good.

[0036] In a preferred embodiment, the porosity of the cold spray coating is ≤0.1%; and / or the expansion coefficient of the cold spray coating is 70×10 -7 ~100×10 -7 / ℃; and / or, the surface roughness of the cold spray coating is 0.1-0.5Ra. The cold spray coating of the present application has a smooth surface, small porosity, a close expansion coefficient with the substrate, good density, and a good protective effect on the substrate.

[0037] In another typical embodiment of the present invention, a method for preparing the above-mentioned cold spray coating is also provided, in which glass powder A, glass powder B, high temperature resistant filler and solvent are mixed according to a component ratio, the obtained cold spray coating is cold sprayed on the surface of a metal substrate, and dried and sintered in sequence to obtain a cold spray coating.

[0038] The cold spray coating of the present application has a simple preparation process, especially a simple spraying process, relatively low cost, small equipment investment, and good overall economic performance. The cold spray coating of the present application has low porosity, good density, and high temperature resistance. When used on the surface of an alloy, it can effectively inhibit corrosion and oxidation of the substrate by high temperature, salt spray, damp heat, high-speed airflow scouring, etc., and play a role in long-term protection of the alloy, thereby significantly extending the service life of the substrate.

[0039] In a preferred embodiment, the mixing method is ball milling and / or stirring; preferably, when the mixing is ball milling, the ball milling speed is 1500-2500rpm, the time is 2-4h, and the ball-to-material ratio is (1-2):1; and / or before cold spraying, the cold spray coating is aged; preferably, the aging time is 10-20 days, and the temperature is 20-40°C. Under the above conditions, the distribution of the components in the cold spray coating is more uniform, which is more conducive to the formation of a dense cold spray coating.

[0040] In a preferred embodiment, the metal substrate comprises one or more of titanium alloy, high temperature alloy and stainless steel, preferably one or more of GH4169 engine flame tube, 1Cr18Ni9Ti gun barrel and GH3044 engine flame tube.

[0041] In order to prevent the cold spray coating from boiling and generating bubbles after contacting the substrate, thereby preparing a denser cold spray coating, in a preferred embodiment, before cold spraying, it also includes a step of controlling the surface temperature of the metal substrate to 0-40°C.

[0042] In a preferred embodiment, the sintering temperature is 1000-1250°C, which is more conducive to the specific component coating of the present application forming a high-temperature resistant ceramic cold spray coating. If the sintering temperature is too high, the coating components may decompose or change phases, resulting in coating failure. If the sintering temperature is too low, the bonding force between the generated coating and the substrate may be insufficient, resulting in coating shedding or peeling. It may also cause uneven distribution of coating components, spots, bubbles, etc. on the coating.

[0043] In a preferred embodiment, spraying is carried out in two steps, and sintering includes a first sintering and a second sintering performed in sequence, and the time of the first sintering and the second sintering is independently 3 to 20 minutes. Under the above conditions, the penetrating micropores can be more fully removed, and the cold spray coating has a smaller porosity and better density. If the sintering time is too short, the glass powders A and B may not be fully melted, and the cold spray coating may not be sintered densely. If the time is too long, the cold spray coating may fail.

[0044] In order to make the protective effect of the cold spray coating better, in a preferred embodiment, the loading amount of the cold spray coating on the substrate surface is 0.15-0.35 kg / m 2 ; and / or the thickness of the cold spray coating is 0.04 to 0.08 mm.

[0045] In another typical embodiment of the present invention, the application of the above-mentioned cold spray coating in the field of alloy protection is also provided. The cold spray coating of the present application has low porosity, good density, and high temperature resistance. When used to protect alloys, it can effectively inhibit the corrosion and oxidation of the substrate caused by high temperature, salt spray, damp heat, high-speed airflow scouring, etc., and play a role in long-term protection of the alloy, thereby significantly extending the service life of the substrate.

[0046] The coating of the present application is suitable for commonly used alloys in the technical field. After a large number of experiments, the inventors have screened the types of alloys that the coating of the present application can be more compatible with. In a preferred embodiment, the alloy includes one or more of titanium alloy, high-temperature alloy and stainless steel; preferably, the model of the titanium alloy is one or more of TC4, TC18 and TC21; the model of the high-temperature alloy is one or more of GH3044, GH4169 and GH4648; the model of the stainless steel is one or more of 0Cr19Ni9, 1Cr18Ni9 and 0Cr18Ni11Nb; and / or, the alloy is used for one or more of the hot end parts of the aircraft engine, the engine blades and the temperature sensor; and / or, the temperature of protection is 0-1200℃, and the time is ≥10000h. When the coating of the specific composition of the present application is used on the surface of the above-mentioned types of alloys through cold spraying technology, the coating is more dense, which can more effectively inhibit the corrosion and oxidation of the substrate by high temperature, salt spray, wet heat, high-speed airflow scouring, etc., and play a role in long-term protection of the alloy, thereby significantly extending the service life of the alloy.

[0047] Typically but not limiting, in the cold spray coating, by weight, glass powder A is 20 parts, 30 parts, 40 parts, 50 parts or a range consisting of any two of them; glass powder B is 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts or a range consisting of any two of them; the high temperature resistant filler is 10 parts, 18 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 61 parts, 70 parts or a range consisting of any two of them; the solvent is 20 parts, 30 parts, 40 parts, 50 parts, 60 parts or a range consisting of any two of them.

[0048] Typically but not limiting, the sum of glass powder A and glass powder B accounts for 30%, 35%, 40% or a range consisting of any two of the above in weight percentage of the cold spray coating.

[0049] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0050] Example 1

[0051] The cold spray coating of the W-200 high temperature resistant ceramic cold spray coating was prepared by weight, and its components were: 37 parts of glass powder A, 12 parts of glass powder B, 46 parts of high temperature resistant filler and 40 parts of solvent, as shown in Table 1, wherein the components of glass powder A and glass powder B are shown in Table 2, the components of high temperature resistant filler are shown in Table 3, and the solvent is water. In the cold spray coating, the particle size of the solid component is controlled at 300-400 meshes.

[0052] Glass powder A, glass powder B, high temperature resistant filler and solvent were put into a sand mill for ball milling, with a ball to material ratio of 1.5:1, a ball milling speed of 2000rpm and a ball milling time of 3h. After ball milling, the cold spray coating was poured out and aged at 25℃ for 14 days before being sprayed on the surface of the GH4169 engine flame tube with a surface temperature of 20℃. The load of the cold spray coating on the alloy surface was controlled to be 0.23kg / m 2 After the cold spray coating is dried, it is put into the furnace and sintered at 1200℃ for 10min. Then it is taken out and cooled to room temperature for the second coating. The load is controlled to be 0.23kg / m 2 , and then continue to sinter at 1200℃ for 10min, and then cool naturally after being taken out of the furnace. The thickness of the cold sprayed coating is 0.08mm.

[0053] Surface photos of cold sprayed coating during sintering process are shown in Figure 1 , the surface photo of the cold spray coating after natural cooling is shown in Figure 2 It has been verified that the cold spray coating has no problems such as scratching or falling off.

[0054] Example 2

[0055] The cold spray coating of the B-1000 high temperature resistant ceramic cold spray coating was prepared by weight, and its components were: 31 parts of glass powder A, 19 parts of glass powder B, 49 parts of high temperature resistant filler and 42 parts of solvent, as shown in Table 1, wherein the components of glass powder A and glass powder B are shown in Table 2, the components of high temperature resistant filler are shown in Table 3, and the solvent is water. In the cold spray coating, the particle size of the solid component is controlled at 300-400 meshes.

[0056] Glass powder A, glass powder B, high temperature resistant filler and solvent were put into a sand mill for ball milling, with a ball-to-material ratio of 1.5:1, a ball milling speed of 2000rpm and a ball milling time of 3h. After ball milling, the cold spray coating was poured out and aged at 25℃ for 14 days before being sprayed on the surface of a 1Cr18Ni9Ti gun barrel with a surface temperature of 20℃. The load of the cold spray coating on the alloy surface was controlled to be 0.23kg / m 2 After the cold spray coating is dried, it is put into the furnace and sintered at 1030℃ for 8min. Then it is taken out and cooled to room temperature for the second coating. The load is controlled to be 0.23kg / m 2 , and then sintered at 1030℃ for 8min, and then cooled naturally after being taken out of the furnace. The thickness of the cold spray coating obtained was 0.08mm. The surface photo of the cold spray coating after natural cooling is shown in Figure 3 .

[0057] Examples 3 to 10

[0058] The only difference from Example 1 is:

[0059] The cold spray coatings have different ingredients and different substrates, see Tables 1 to 3 for details.

[0060] Embodiment 11

[0061] The only difference from Example 1 is:

[0062] Glass powder A, glass powder B, high temperature resistant filler and solvent were put into a sand mill for ball milling, with a ball-to-material ratio of 1:1, a ball milling speed of 2500rpm and a ball milling time of 2h. After ball milling, the cold spray coating was poured out and aged at 20℃ for 20 days before being sprayed on the surface of the GH4169 engine flame tube with a surface temperature of 0℃. The load of the cold spray coating on the alloy surface was controlled to be 0.15kg / m 2 After the cold spray coating is dried, it is put into the furnace and sintered at 1000℃ for 20min. Then it is taken out and cooled to room temperature for the second coating. The load is controlled to be 0.15kg / m 2 , and then continue to sinter at 1000℃ for 20min, and then cool naturally after being taken out of the furnace. The thickness of the cold sprayed coating is 0.04mm.

[0063] Example 12

[0064] The only difference from Example 1 is:

[0065] Glass powder A, glass powder B, high temperature resistant filler and solvent were put into a sand mill for ball milling, with a ball-to-material ratio of 2:1, a ball milling speed of 1500rpm and a ball milling time of 4h. After ball milling, the cold spray coating was poured out and aged at 40℃ for 10 days before being sprayed on the surface of the GH4169 engine flame tube with a surface temperature of 40℃. The load of the cold spray coating on the alloy surface was controlled to be 0.35kg / m 2 After the cold spray coating is dried, it is put into the furnace and sintered at 1250℃ for 3min. Then it is taken out and cooled to room temperature for the second coating. The load is controlled to be 0.35kg / m 2 , and then continue to sinter at 1250℃ for 3min, and then cool naturally after being taken out of the furnace. The thickness of the cold sprayed coating is 0.08mm.

[0066] Comparative Example 1

[0067] The only difference from Example 1 is:

[0068] The cold spray coating does not contain glass powder A.

[0069] Comparative Example 2

[0070] The only difference from Example 1 is:

[0071] The cold spray coating does not contain glass powder B.

[0072] Comparative Example 3

[0073] The only difference from Example 1 is:

[0074] In the cold spray coating, the content of glass powder A is 10 parts.

[0075] Comparative Example 4

[0076] The only difference from Example 1 is:

[0077] In the cold spray coating, the content of glass powder A is 60 parts.

[0078] Comparative Example 5

[0079] The only difference from Example 1 is:

[0080] The content of glass powder B in the cold spray coating is 2 parts.

[0081] Comparative Example 6

[0082] The only difference from Example 1 is:

[0083] The content of glass powder B in the cold spray coating is 43 parts.

[0084] The performance test results of the cold spray paint and cold spray coating prepared in the above examples and comparative examples are shown in Table 4.

[0085] Test method:

[0086] Softening temperature test: refer to "JC / T 751-1996, Test method for softening point of quartz glass (wire drawing method)" for testing.

[0087] Loading amount on the substrate surface: the ratio of the coverage per unit area to the coating thickness.

[0088] Porosity: The SEM images of the coating were analyzed using Image J software, and the porosity of the coating was obtained by taking the average value after multiple measurements.

[0089] Glass transition temperature, melting point, expansion coefficient α 20 / 400 : The thermal expansion coefficient of the coating was measured by a high-temperature thermal expansion instrument. The test temperature range was 20-1400°C, the heating rate was 5°C / min, and the test atmosphere was argon.

[0090] Surface roughness test: Use a handheld roughness meter to test the surface roughness of the coating. Place the sensor on the coating surface to be tested. The sensor uses the sharp contact needle inside to test the roughness of the coating surface.

[0091] Table 1

[0092]

[0093] Table 2

[0094]

[0095]

[0096] Table 3

[0097]

[0098] Table 4

[0099]

[0100]

[0101] In the coatings with specific components in each embodiment of the present invention, the glass powder has a relatively low softening temperature, so the cold spray coating can be sprayed at room temperature, and then sintered to form a cold spray coating on the surface of the metal substrate. The glass powder B with specific components in the present application has a low softening temperature. After the cold spray coating enters the furnace, it can soften quickly and form a dense film layer, which effectively isolates the corrosion of oxygen and other gases on the substrate, so that the substrate is not oxidized during the sintering process; on the other hand, the glass powder B has a large expansion coefficient, so that the expansion coefficient of the cold spray coating is similar to and slightly lower than that of the substrate metal, and there are certain tensile stresses and compressive stresses between the metal and the cold spray coating, which can withstand large compressive stresses and is not easy to break, so that the cold spray coating can exist densely on the metal surface. Secondly, the glass powder A with specific components in the present application has a high softening temperature and a high-temperature viscosity. During the high-temperature sintering process, the addition of glass powder A can effectively increase the sintering temperature of the cold spray coating, which is conducive to the formation of a dense cold spray coating. In addition, the addition of high-temperature resistant fillers with specific components can effectively improve the high-temperature resistance and high-temperature stability of the cold spray coating. Among them, Cr 2 O 3 and Cr 2 C 3 The mutual synergy can effectively enhance the bonding strength between the cold spray coating and the base metal at high temperature, and is conducive to the formation of a dense cold spray coating.

[0102] From the above, it can be seen that compared with the comparative example, the coating of the present invention can be prepared by cold spraying technology, and the obtained coating has small porosity and high density. When used on the surface of alloys such as titanium alloys, high-temperature alloys, and stainless steel, it can effectively inhibit the corrosion and oxidation of the substrate caused by high temperature, salt spray, damp heat, and high-speed airflow scouring, and play a role in long-term protection of the alloy, thereby significantly extending the service life of the alloy.

[0103] In addition, it can be seen that when all process parameters are within the preferred range of the present invention, the surface of the cold spray coating is smoother, the porosity is smaller, the expansion coefficient is closer to that of the substrate, the density is better, the protection effect on the substrate is better, and the service life of the substrate can be more significantly extended.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cold spray coating, characterized in that: The cold spray coating comprises, by weight, 20 to 50 parts of glass powder A, 5 to 30 parts of glass powder B, 10 to 70 parts of high temperature resistant filler and 20 to 60 parts of solvent; Wherein, the glass powder A comprises 30 to 50 parts of SiO2, 20 to 40 parts of BaO, 1 to 15 parts of Al2O3, 1 to 15 parts of B2O3, 0 to 10 parts of Na2O, 5 to 20 parts of TiO2 and 1 to 10 parts of CaO; The glass powder B comprises 5 to 30 parts of SiO2, 1 to 20 parts of Al2O3, 1 to 20 parts of BaO, 5 to 20 parts of B2O3, 5 to 20 parts of Na2O, 5 to 20 parts of K2O, 1 to 10 parts of MgO and 1 to 10 parts of CaO; The high temperature resistant filler includes Al2O3, ZrO2, SiO2, Cr2O3, Cr2C3 and bentonite.

2. The cold spray coating according to claim 1, characterized in that: By weight, The cold spray coating comprises 30-40 parts of glass powder A, 10-20 parts of glass powder B, 18-61 parts of high temperature resistant filler and 30-50 parts of solvent; preferably, the sum of the glass powder A and the glass powder B accounts for 30-40% of the cold spray coating in terms of weight percentage; and / or, The glass powder A comprises 35-45 parts of SiO2, 25-35 parts of BaO, 5-10 parts of Al2O3, 5-10 parts of B2O3, 0-5 parts of Na2O, 10-15 parts of TiO2 and 1-5 parts of CaO; and / or, The glass powder B includes 10 to 20 parts of SiO2, 5 to 10 parts of Al2O3, 5 to 10 parts of BaO, 8 to 15 parts of B2O3, 10 to 15 parts of Na2O, 7 to 12 parts of K2O, 1 to 5 parts of MgO and 2 to 6 parts of CaO.

3. The cold spray coating according to claim 1 or 2, characterized in that: By weight, The high temperature resistant filler comprises 3 to 10 parts of Al2O3, 2 to 10 parts of ZrO2, 2 to 15 parts of SiO2, 5 to 10 parts of Cr2O3, 3 to 8 parts of Cr2C3 and 3 to 8 parts of bentonite; and / or, The solvent includes one or more of water, isopropanol and ethanol.

4. The cold spray coating according to any one of claims 1 to 3, characterized in that: In the cold spray coating, the particle size of the solid component is 200 to 400 meshes; and / or, The softening temperature of the cold spray coating is 1000-1200°C; and / or the glass transition temperature of the cold spray coating is 800-1000°C.

5. A cold spray coating, characterized in that: The cold spray coating according to any one of claims 1 to 4 is obtained by cold spraying and sintering.

6. The cold spray coating according to claim 5, characterized in that: The porosity of the cold spray coating is ≤0.1%; and / or, The expansion coefficient of the cold spray coating is 70×10 -7 ~100×10 -7 / ℃; and / or, The surface roughness of the cold spray coating is 0.1-0.5 Ra.

7. The method for preparing the cold spray coating according to claim 5 or 6, characterized in that: Glass powder A, glass powder B, high temperature resistant filler and solvent are mixed according to the composition ratio, the obtained cold spray coating is cold sprayed on the surface of the metal substrate, and then dried and sintered in sequence to obtain the cold spray coating.

8. The preparation method according to claim 7, characterized in that: The mixing method is ball milling and / or stirring; and / or, Before the cold spraying, the method further comprises the step of aging the cold spray coating; preferably, the aging time is 10 to 20 days at a temperature of 20 to 40° C.; and / or, The metal substrate comprises one or more of titanium alloy, high temperature alloy and stainless steel; and / or, Before the cold spraying is performed, the method further includes controlling the surface temperature of the metal substrate to be 0-40°C.

9. The preparation method according to claim 7 or 8, characterized in that: The sintering temperature is 1000-1250° C.; and / or, The cold spray coating has a loading amount of 0.15 to 0.35 kg / m 2 and / or, The thickness of the cold spray coating is 0.04-0.08 mm.

10. Use of the cold spray coating according to claim 5 or 6 in the field of alloy protection.

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