Splash-proof shielding putty for vacuum brazing and preparation method thereof

Abstract

The invention provides splash-proof shielding putty for vacuum brazing and a preparation method of the splash-proof shielding putty for vacuum brazing, and the splash-proof shielding putty for vacuum brazing comprises the following components in parts by mass: 4-6 parts of methyl methacrylate; 0.1 to 0.5 part of butyl methacrylate; 0.05 to 0.10 part of a catalyst; 34 to 38 parts of dibutyl phthalate; 0.3 to 0.5 part of a dispersant; 28-31 parts of a nickel source; and 30-33 parts of a carbon source. The splash-proof shielding putty for vacuum brazing prepared from the components is applied to a target area, the effect of preventing welding flux from being sputtered to a non-welding area in the vacuum brazing period is achieved, local splash-through protection of gas-phase splashed aluminum can be achieved, the purpose of immovable treatment of the same workpiece is achieved, the shielding effect is good, the cost is low, and the application range is wide. The preparation method is simple, has good environmental and economic benefits, is suitable for large-scale popularization and industrial production, fills the blank of domestic related technologies, and has positive significance in promoting the development of a vacuum brazing technology.

Description

Technical Field

[0001] The invention relates to the technical field of material science, and in particular to an anti-splash shielding putty for vacuum brazing and a preparation method thereof. Background Art

[0002] Brazing refers to a welding method in which the gap of solid workpieces is filled with liquid brazing material to connect metals after the brazing material and the workpiece are heated to the melting temperature of the brazing material at the same time. It is one of the earliest material connection methods used by humans. Before humans began to use iron tools, they had invented the method of connecting metals by brazing. Brazing has small deformation and smooth and beautiful joints. It is suitable for welding precise, complex and components composed of different materials, such as honeycomb structure plates, turbine blades, carbide tools and printed circuit boards. Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil and excessively thick oxide films to ensure the assembly gap of the interface. The gap is generally required to be between 0.01-0.1 mm. The weld formed by brazing is called a brazing seam. The filler metal used for brazing is called brazing material. Brazing process: The workpieces with cleaned surfaces are assembled together in an overlapping manner, and the brazing material is placed near or between the joint gaps. When the workpiece and the brazing filler metal are heated to a temperature slightly higher than the melting point of the brazing filler metal, the brazing filler metal melts (the workpiece does not melt) and is sucked into and fills the gap between the solid workpieces by capillary action. The liquid brazing filler metal and the workpiece metal diffuse and dissolve into each other, and a brazed joint is formed after condensation.

[0003] Although brazing technology appeared early, it did not develop significantly for a long time.

[0004] Vacuum brazing is a relatively new brazing method that heats the workpiece in a vacuum chamber and does not apply flux under vacuum conditions. Because the workpiece is in a vacuum condition, the harmful effects of air on the workpiece are eliminated, so welding can be performed without flux. It is mainly used for welding of high-quality products and easily oxidized materials such as aluminum alloys, titanium alloys, high-temperature alloys, refractory metals and ceramics. Vacuum brazing technology has become a very promising welding technology. Because vacuum brazing does not require the filling of metal flux, it not only saves a lot of expensive metal flux, significantly improves the corrosion resistance of the product, eliminates various pollution, and does not require a complicated flux cleaning process, which greatly reduces the production cost compared to traditional brazing; and the vacuum brazing brazing filler metal has good wettability and fluidity, and can weld more complex and narrow channel workpieces, improve the product yield, and obtain a solid and clean working surface.

[0005] When vacuum brazing workpieces, according to actual requirements, part of the workpiece needs to be shielded to prevent solder from splashing to non-welding areas and affecting the product surface.

[0006] Chinese patent CN105215574A "An iron-based solder for stainless steel brazing" discloses a paste-like iron-based solder including nickel powder and graphite powder, which has a low melting point and strong corrosion resistance. However, the patent belongs to the solder and does not include a shielding effect. It does not study products that can shield part of the workpiece during vacuum brazing.

[0007] Therefore, it is of great significance to develop a splash-proof shielding putty for vacuum brazing which has simple production conditions and low price and can be used for the splash-proof shielding purposes of vacuum brazing and a preparation method thereof. Summary of the invention

[0008] In view of the fact that there are few domestic studies on related aspects of existing products that can shield part of the workpiece during vacuum brazing, the sources of related products mainly rely on imports, the prices are relatively expensive, and the production process is complicated, the present invention provides a splash-proof shielding putty for vacuum brazing and a preparation method thereof, which is prepared by mixing a plurality of organic and inorganic materials to prepare a finished putty, which is applied to the target area to achieve the purpose of preventing solder from splashing to the non-welding area during vacuum brazing. The obtained splash-proof shielding putty for vacuum brazing has good shielding effect, low cost, simple preparation method, good environmental and economic benefits, is suitable for large-scale promotion and industrial production, and has positive significance for promoting the development of vacuum brazing technology.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A splash-proof shielding putty for vacuum brazing, comprising the following components in parts by mass:

[0011] 4-6 parts of methyl methacrylate;

[0012] Butyl methacrylate 0.1-0.5 parts;

[0013] Catalyst 0.05-0.10 parts;

[0014] 34-38 parts of dibutyl phthalate;

[0015] Dispersant 0.3-0.5 parts;

[0016] Nickel source 28-31 parts;

[0017] 30-33 parts of carbon source.

[0018] The present application prepares a finished putty by mixing a plurality of organic and inorganic materials, wherein a carbon source serves as a skeleton of the splash-proof shielding putty for vacuum brazing, and plays a supporting and molding role; methyl methacrylate reacts with butyl methacrylate to form a polymer, and provides an adhesive effect; dibutyl phthalate plays an important role in polymerizing the various components in the present invention; a catalyst catalyzes the reaction of the above-mentioned polymers; a nickel source serves as a main component for preventing sputtering penetration; and a dispersant can prevent agglomeration of solid materials in the splash-proof shielding putty for vacuum brazing, and is applied to the target area, so as to prevent solder from sputtering to non-welding areas during vacuum brazing.

[0019] Furthermore, the following components are included in parts by mass:

[0020] 4.36 parts of methyl methacrylate;

[0021] 0.15 parts of butyl methacrylate;

[0022] Catalyst 0.08 parts;

[0023] 35.76 parts of dibutyl phthalate;

[0024] Dispersant 0.36 parts;

[0025] Nickel source 28.07 parts;

[0026] 31.22 parts of carbon source.

[0027] Furthermore, the catalyst is dibenzoyl peroxide, and the dispersant is an aqueous ethyl ester and alkane-based composite dispersant.

[0028] Furthermore, the nickel source is nickel powder with a mesh size of ≥300 meshes.

[0029] Furthermore, the carbon source is graphite powder with a mesh size of ≥300 meshes.

[0030] Furthermore, the purity of the component is ≥99%.

[0031] Another object of the present invention is to provide a method for preparing an anti-splash shielding putty for vacuum brazing.

[0032] A method for preparing the splash-proof shielding putty for vacuum brazing according to any of the above items comprises the following steps:

[0033] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, heat and stir to obtain a mixed material;

[0034] S2. The mixture in S1 is cooled to room temperature, dibutyl phthalate and a dispersant are added, and stirred to obtain a mixed liquid;

[0035] S3. Continue stirring the mixed liquid in S2, add the nickel source in portions, and mix thoroughly; then add the carbon source in portions, stir and knead until the sample becomes a paste, and refrigerate to obtain the splash-proof shielding putty for vacuum brazing.

[0036] Furthermore, the heating and stirring temperature in S1 is 80-100° C., and the time is 30-60 min.

[0037] Furthermore, the heating and stirring temperature in S1 is 90° C. and the time is 30-45 min.

[0038] Furthermore, the stirring time in S2 is 3-7 min.

[0039] Furthermore, the stirring time in S2 is 5 minutes.

[0040] Furthermore, the amount of the nickel source added in batches in S3 is 25-50% of the remaining amount each time, the amount of the carbon source added in batches in S3 is 25-50% of the remaining amount each time, and the time intervals for the batch additions are independently 1-3 minutes.

[0041] Furthermore, the refrigeration time in S3 is 12 hours.

[0042] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0043] The present application prepares a splash-proof shielding putty for vacuum brazing by mixing a plurality of organic and inorganic materials such as methyl methacrylate, butyl methacrylate, a catalyst, dibutyl phthalate, a dispersant, a nickel source, a carbon source, etc., and compounding them in a certain proportion; wherein methyl methacrylate has low viscosity and good fluidity, and can easily penetrate into small cracks or even fine cracks invisible to the naked eye, and at the same time forms a thin film on the surface, which plays a good surface sealing role, and also has excellent mechanical properties and high bonding strength, and reacts with butyl methacrylate and dibutyl phthalate under the action of a catalyst to form a polymer, which can provide excellent mechanical properties and high bonding strength to the splash-proof shielding putty for vacuum brazing of the present application; the nickel source has stable chemical properties and high corrosion resistance, and as the main component for preventing sputtering penetration, it has good anti-penetration effect and strong shielding property, so that the present application The splash-proof shielding putty applied for vacuum brazing has excellent splash-proof shielding effect; the carbon source serves as the putty skeleton and plays a supporting molding role; the dispersant can prevent the agglomeration of solid materials in the splash-proof shielding putty, and keep the splash-proof shielding putty for vacuum brazing of this application uniform in composition and stable in performance, so that the present invention has a lasting and excellent effect. The splash-proof shielding putty for vacuum brazing prepared by the above-mentioned ingredients is applied to the target area to achieve the effect of preventing solder from splashing to non-welding areas during vacuum brazing, and can achieve local splash protection against gas-phase splashing aluminum, achieving the purpose of the same workpiece unmoving treatment method, with good shielding effect, low cost, simple preparation method, good environmental and economic benefits, suitable for large-scale promotion and industrial production, filling the gap in related domestic technologies, and having positive significance for promoting the development of vacuum brazing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0045] Figure 1 The microstructure diagrams of the substrate shielded by the anti-splash shielding putty used for vacuum brazing of the present application after a simulated sputtering test; (a) is Example 1, (b) is Example 3, (c) is Comparative Example 1, and (d) is Comparative Example 2.

[0046] Figure 2 This is a macroscopic image of the splash-proof shielding putty used for vacuum brazing in this application. DETAILED DESCRIPTION

[0047] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention is further described by the following examples. Obviously, the following examples are only part of the embodiments of the present invention, rather than all the embodiments; it should be understood that the embodiments of the present invention are only used to illustrate the technical effects of the present invention, rather than to limit the scope of protection of the present invention.

[0048] The present invention will be specifically described below by examples, and these examples are not intended to limit the present invention in any way. It will be appreciated by those skilled in the art that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods for the unrecorded specific conditions in the following examples are usually performed under normal conditions or according to the conditions recommended by the manufacturer. Unless otherwise indicated, percentages and parts are calculated by weight. The following examples are mainly for a better understanding of the analytical method of the present invention and do not exhaust all operating modes. Parts by weight hereinafter may represent conventional unit measurements in the art, such as kilograms, grams, etc., or may represent ratios between the components, such as mass or weight ratios, etc.

[0049] The raw materials in the examples can all be obtained commercially; unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0050] Example 1

[0051] A method for preparing a splash-proof shielding putty for vacuum brazing comprises the following steps:

[0052] The splash-proof shielding putty for vacuum brazing comprises the following components: 4.68 parts of methyl methacrylate, 0.23 parts of butyl methacrylate, 0.09 parts of dibenzoyl peroxide, 36.30 parts of dibutyl phthalate, 0.46 parts of water-based ethyl ester and alkane-based composite dispersant, 28.23 parts of nickel powder, and 31.47 parts of graphite powder;

[0053] The mesh numbers of the nickel powder and graphite powder are ≥300 meshes, and the purity of the components is ≥99%.

[0054] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, and heat and stir at 90 ° C for 35 min to obtain a mixed material;

[0055] S2. The mixture in S1 was cooled to room temperature, dibutyl phthalate and a dispersant were added, and stirred for 5 min to obtain a mixed liquid;

[0056] S3. Continue stirring the mixed liquid described in S2, add nickel source in portions, each adding amount is 25% of the remaining amount, with an interval of 2 minutes, and mix thoroughly; then add carbon source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in a refrigerator for 12 hours to obtain the splash-proof shielding putty for vacuum brazing.

[0057] Example 2

[0058] A method for preparing a splash-proof shielding putty for vacuum brazing comprises the following steps:

[0059] The splash-proof shielding putty for vacuum brazing comprises the following components: 4.36 parts of methyl methacrylate, 0.15 parts of butyl methacrylate, 0.08 parts of dibenzoyl peroxide, 35.76 parts of dibutyl phthalate, 0.36 parts of water-based ethyl ester and alkane-based composite dispersant, 28.07 parts of nickel powder, and 31.22 parts of graphite powder;

[0060] The mesh numbers of the nickel powder and graphite powder are ≥300 meshes, and the purity of the components is ≥99%.

[0061] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, and heat and stir at 90 ° C for 45 min to obtain a mixed material;

[0062] S2. The mixture in S1 was cooled to room temperature, dibutyl phthalate and a dispersant were added, and stirred for 5 min to obtain a mixed liquid;

[0063] S3. Continue stirring the mixed liquid described in S2, add nickel source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, and mix thoroughly; then add carbon source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in a refrigerator for 12 hours to obtain the splash-proof shielding putty for vacuum brazing.

[0064] Example 3

[0065] A method for preparing a splash-proof shielding putty for vacuum brazing comprises the following steps:

[0066] The splash-proof shielding putty for vacuum brazing comprises the following components: 5.16 parts of methyl methacrylate, 0.45 parts of butyl methacrylate, 0.06 parts of dibenzoyl peroxide, 37.73 parts of dibutyl phthalate, 0.42 parts of water-based ethyl ester and alkane-based composite dispersant, 30.17 parts of nickel powder, and 32.24 parts of graphite powder;

[0067] The mesh numbers of the nickel powder and graphite powder are ≥300 meshes, and the purity of the components is ≥99%.

[0068] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, heat and stir at 90 ° C for 30 min to obtain a mixed material;

[0069] S2. The mixture in S1 was cooled to room temperature, dibutyl phthalate and a dispersant were added, and stirred for 5 min to obtain a mixed liquid;

[0070] S3. Continue stirring the mixed liquid described in S2, add nickel source in batches, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, and mix thoroughly; then add carbon source in batches, each adding amount is 25% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in a refrigerator for 12 hours to obtain the splash-proof shielding putty for vacuum brazing.

[0071] Comparative Example 1

[0072] A method for preparing an anti-splash shielding putty comprises the following steps:

[0073] The splash-proof masking putty comprises the following components: 4.36 parts of methyl methacrylate, 0.15 parts of butyl methacrylate, 0.08 parts of dibenzoyl peroxide, 35.76 parts of dibutyl phthalate, 0.36 parts of water-based ethyl ester and alkane-based composite dispersant, and 31.22 parts of graphite powder;

[0074] The mesh number of the graphite powder is ≥300 meshes, and the purity of the component is ≥99%.

[0075] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, and heat and stir at 90 ° C for 45 min to obtain a mixed material;

[0076] S2. The mixture in S1 was cooled to room temperature, dibutyl phthalate and a dispersant were added, and stirred for 5 min to obtain a mixed liquid;

[0077] S3. Continue stirring the mixed liquid in S2, add the carbon source in portions, each adding 50% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in a refrigerator for 12 hours to obtain the splash-proof masking putty.

[0078] Compared with Example 2, no nickel source was added in this comparative example.

[0079] Comparative Example 2

[0080] Use commercially available putty.

[0081] Comparative Example 3

[0082] A method for preparing an anti-splash shielding putty comprises the following steps:

[0083] The splash-proof masking putty comprises the following components: 4.36 parts of methyl methacrylate, 0.15 parts of butyl methacrylate, 0.08 parts of dibenzoyl peroxide, 0.36 parts of water-based ethyl ester and alkane-based composite dispersant, 28.07 parts of nickel powder, and 31.22 parts of graphite powder;

[0084] The mesh numbers of the nickel powder and graphite powder are ≥300 meshes, and the purity of the components is ≥99%.

[0085] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, and heat and stir at 90 ° C for 45 min to obtain a mixed material;

[0086] S2. The mixed material in S1 is cooled to room temperature, a dispersant is added, and stirred for 5 min to obtain a mixed liquid;

[0087] S3. Continue stirring the mixed liquid described in S2, add the nickel source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, and mix thoroughly; then add the carbon source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in the refrigerator for 12 hours to obtain the splash-proof shielding putty.

[0088] Compared with Example 1, dibutyl phthalate is not added in this comparative example.

[0089] Comparative Example 4

[0090] A method for preparing an anti-splash shielding putty comprises the following steps:

[0091] The splash-proof shielding putty comprises the following components: 4.36 parts of methyl methacrylate, 0.15 parts of butyl methacrylate, 0.08 parts of dibenzoyl peroxide, 35.76 parts of dibutyl phthalate, 28.07 parts of nickel powder, and 31.22 parts of graphite powder;

[0092] The mesh numbers of the nickel powder and graphite powder are ≥300 meshes, and the purity of the components is ≥99%.

[0093] S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, and heat and stir at 90 ° C for 45 min to obtain a mixed material;

[0094] S2. The mixture in S1 was cooled to room temperature, dibutyl phthalate was added, and stirred for 5 min to obtain a mixed liquid;

[0095] S3. Continue stirring the mixed liquid described in S2, add the nickel source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, and mix thoroughly; then add the carbon source in portions, each adding amount is 50% of the remaining amount, with an interval of 2 minutes, stir and knead until the sample becomes a paste, and put it in the refrigerator for 12 hours to obtain the splash-proof shielding putty.

[0096] Compared with Example 1, no dispersant was added in this comparative example.

[0097] Related performance tests:

[0098] The splash-proof shielding putties provided in the above-mentioned Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests, and the specific test methods are as follows:

[0099] Coating anti-sputtering test: The test piece is coated with samples, and a control group is set up and placed in a vapor phase aluminizing furnace for aluminizing experiments to simulate the brazing environment.

[0100] In Comparative Example 3, since no dibutyl phthalate was added, the splash-proof masking putty could not be aggregated and formed, and therefore, the test could not be performed.

[0101] The specific test results of Examples 1-3 and Comparative Examples 1-4 are shown in Table 1 below:

[0102] Table 1 Comparison of penetration thickness and penetration amount between Examples 1-3 and Comparative Examples 1-4

[0103]

[0104]

[0105] It can be seen from the above table that the substrate penetration depth shielded by the splash-proof shielding putty used for vacuum brazing in each embodiment of the present application is less than 15μm, and the aluminum penetration amount is less than 3wt.%, which has excellent splash-proof shielding effect and can achieve local splash protection against gas-phase splashing aluminum, thereby achieving the purpose of different treatment methods for the same workpiece.

[0106] The splash-proof shielding putty of comparative example 1 does not add nickel source, and the penetration depth is as high as 21.01μm, and the aluminum penetration amount is also higher than 10wt.%, reaching 10.47wt.%, with strong permeability and poor shielding effect; Comparative example 2 is a commercially available putty with a penetration depth of 15.15μm and an aluminum penetration amount of 8.48wt.%, which has a certain splash-proof shielding effect, but is far from comparable with the various embodiments. It can be seen that the performance of the present invention is better than that of ordinary commercial products; Comparative example 3 does not add dibutyl phthalate, so the splash-proof shielding putty cannot be agglomerated and formed, and has no application value. It can be seen that dibutyl phthalate plays an important role in polymerizing various components in the present invention; Comparative example 4 does not add dispersant, which leads to agglomeration and uneven distribution of effective ingredients. In the coating splash-proof test, uneven splash-proof shielding occurs, the penetration depth reaches 21.03μm, and the aluminum penetration amount is 9.36wt.%.

[0107] The splash-proof shielding putties of Example 1, Example 3 and Comparative Example 1 and Comparative Example 2 were characterized and analyzed, and the results are as follows:

[0108] Figure 1 The microstructure diagrams of the substrate shielded by the anti-splash shielding putty used for vacuum brazing of the present application after a simulated sputtering test; (a) is Example 1, (b) is Example 3, (c) is Comparative Example 1, and (d) is Comparative Example 2.

[0109] Depend on Figure 1 It can be seen that the anti-splash shielding putty for vacuum brazing obtained in this embodiment has good shielding property and shallow penetration depth, which can achieve the purpose of preventing solder from splashing to non-welding areas during vacuum brazing; while the substrate shielded by the anti-splash shielding putty of comparative example 1 has a deep penetration depth and a large amount of aluminum penetration, and a large number of aluminum-infiltrated particles can be seen, with good permeability, poor shielding property, and poor anti-splash shielding effect; the aluminum-infiltrated particles of the substrate shielded by the commercially available putty of comparative example 2 are significantly reduced compared with comparative example 1, indicating that it has a certain anti-splash shielding effect, but is still more than that of each embodiment, indicating that the performance of the present invention is better than that of ordinary commercially available products.

[0110] The test results of the other embodiments are basically consistent with it.

[0111] like Figure 2 As shown, the splash-proof shielding putty used for vacuum brazing in the present application is well formed, easy to apply, and has good application value.

[0112] In summary, the present application prepares a splash-proof shielding putty for vacuum brazing by mixing a plurality of organic and inorganic materials such as methyl methacrylate, butyl methacrylate, a catalyst, dibutyl phthalate, a dispersant, a nickel source, a carbon source, etc.; wherein methyl methacrylate has low viscosity and good fluidity, and can play a good surface sealing role, and reacts with butyl methacrylate and dibutyl phthalate under the action of a catalyst to form a polymer, which can provide excellent mechanical properties and high bonding strength to the splash-proof shielding putty for vacuum brazing of the present application; the nickel source, as the main component to prevent sputtering penetration, has good anti-penetration effect and strong shielding property, so that the splash-proof shielding putty for vacuum brazing of the present application has excellent Anti-splash shielding effect; the carbon source serves as the putty skeleton and plays a supporting molding role; the dispersant can prevent the agglomeration of solid materials in the anti-splash shielding putty, so that the invention has a lasting and excellent effect. The anti-splash shielding putty for vacuum brazing prepared by the above ingredients is applied to the target area to achieve the effect of preventing solder from sputtering to non-welding areas during vacuum brazing, and can achieve local splash protection against gas-phase splashing aluminum, achieving the purpose of the unmovable treatment method for the same workpiece, with good shielding effect, low cost, simple preparation method, good environmental and economic benefits, suitable for large-scale promotion and industrial production, filling the gap in related domestic technologies, and having positive significance for promoting the development of vacuum brazing technology.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A splash-proof shielding putty for vacuum brazing, characterized in that: In parts by mass, it includes the following components: 4-6 parts of methyl methacrylate; Butyl methacrylate 0.1-0.5 parts; Catalyst 0.05-0.10 parts; 34-38 parts of dibutyl phthalate; Dispersant 0.3-0.5 parts; Nickel source 28-31 parts; 30-33 parts of carbon source.

2. A splash-proof shielding putty for vacuum brazing according to claim 1, characterized in that: In parts by mass, it includes the following components: 4.36 parts of methyl methacrylate; 0.15 parts of butyl methacrylate; Catalyst 0.08 parts; 35.76 parts of dibutyl phthalate; Dispersant 0.36 parts; Nickel source 28.07 parts; 31.22 parts of carbon source.

3. A splash-proof shielding putty for vacuum brazing according to claim 1, characterized in that: The catalyst is dibenzoyl peroxide, and the dispersant is a water-based ethyl ester and alkane-based composite dispersant.

4. A splash-proof shielding putty for vacuum brazing according to claim 1, characterized in that: The nickel source is nickel powder, with a mesh size of ≥300 meshes.

5. A splash-proof shielding putty for vacuum brazing according to claim 1, characterized in that: The carbon source is graphite powder with a mesh size of ≥300 meshes.

6. A splash-proof shielding putty for vacuum brazing according to claim 1, characterized in that: The purity of the component is ≥99%.

7. A method for preparing the splash-proof shielding putty for vacuum brazing according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh the components according to the ratio, mix methyl methyl propionate, butyl methyl propionate and the catalyst, heat and stir to obtain a mixed material; S2. The mixture in S1 is cooled to room temperature, dibutyl phthalate and a dispersant are added, and stirred to obtain a mixed liquid; S3. Continue stirring the mixed liquid in S2, add the nickel source in portions, and mix thoroughly; then add the carbon source in portions, stir and knead until the sample becomes a paste, and refrigerate to obtain the splash-proof shielding putty for vacuum brazing.

8. A method for preparing splash-proof shielding putty for vacuum brazing according to claim 7, characterized in that: The heating and stirring temperature in S1 is 80-100°C and the time is 30-60min.

9. A method for preparing splash-proof shielding putty for vacuum brazing according to claim 7, characterized in that: The stirring time in S2 is 3-7 min.

10. A method for preparing splash-proof shielding putty for vacuum brazing according to claim 7, characterized in that: The amount of the nickel source added in batches in S3 is 25-50% of the remaining amount each time, and the amount of the carbon source added in batches in S3 is 25-50% of the remaining amount each time, and the time intervals of the batch additions are independently 1-3 minutes.

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