阅读说明：本技术 一种钎焊助剂浆液的制备方法、钎焊助剂浆液及其应用 (Preparation method of brazing assistant slurry, brazing assistant slurry and application thereof ) 是由 孙韶 于 2021-09-22 设计创作，主要内容包括：本申请涉及钎焊领域,具体公开了一种钎焊助剂浆液的制备方法、钎焊助剂浆液及其应用；一种钎焊助剂浆液的制备方法,包括如下步骤：称取重量比为1:20-100的纤维素和水,纤维素溶于水不溶于醇,搅拌至纤维素溶解制得混合液；按重量比为1:5-100称取混合液和醇,经搅拌、蒸馏,制得混合物；按重量比为1:1称取混合物和助焊剂粉末,经搅拌,制得成品钎焊助剂浆液；采用钎焊用钎焊助剂浆液的制备方法制备钎焊助剂浆液；一种钎焊用钎焊助剂浆液的应用,包括如下步骤：将钎焊助剂浆液涂覆至被焊材料焊接接缝位置处,涂覆结束后,在接缝位置处喷水,制得成品钎焊组件；具有涂覆过程中易于涂覆,涂覆后减少无序流动的优点。(The application relates to the field of brazing, and particularly discloses a preparation method of brazing auxiliary agent slurry, the brazing auxiliary agent slurry and application thereof; a method for preparing a brazing assistant slurry, comprising the steps of: weighing cellulose and water in a weight ratio of 1:20-100, dissolving the cellulose in the water and not dissolving the cellulose in alcohol, and stirring until the cellulose is dissolved to obtain a mixed solution; weighing the mixed solution and alcohol according to the weight ratio of 1:5-100, stirring and distilling to obtain a mixture; weighing the mixture and the soldering flux powder according to the weight ratio of 1:1, and stirring to obtain a finished soldering flux slurry; preparing brazing auxiliary agent slurry by adopting a preparation method of the brazing auxiliary agent slurry for brazing; use of a brazing aid slurry for brazing comprising the steps of: coating the brazing auxiliary agent slurry on the position of a welded joint of the materials to be welded, and spraying water on the position of the joint after coating to obtain a finished brazing assembly; has the advantages of easy coating in the coating process and reduction of disordered flowing after coating.)

1. A method for preparing a brazing assistant slurry, comprising the steps of:

s1, weighing cellulose and water in a weight ratio of 1:20-100, dissolving the cellulose in the water and not dissolving the cellulose in alcohol, and stirring until the cellulose is dissolved to obtain a mixed solution;

s2, weighing the mixed solution and alcohol according to the weight ratio of 1:5-100, stirring and distilling to obtain a mixture;

s3, weighing the mixture and the soldering flux powder according to the weight ratio of 1:1, and stirring to obtain the finished soldering flux slurry.

2. The method of preparing a brazing aid slurry according to claim 1, wherein: the alcohol is added into the mixed liquid at the flow rate of 0.2-5g/s, and the stirring speed is 500-1200 r/min.

3. The method of claim 1, wherein the cellulose is selected from one or more of hydroxymethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, and carboxymethyl cellulose.

4. The method of claim 1, wherein the alcohol is selected from one or more of propylene glycol, glycerol, butylene glycol, n-butanol, and hexylene glycol.

5. A brazing aid slurry obtained by the method of producing a brazing aid slurry according to any one of claims 1 to 4.

6. Use of a brazing aid slurry, comprising the steps of:

and (3) coating the brazing auxiliary agent slurry on the position of the welding joint of the welded material, and spraying water on the position of the joint after coating to obtain the finished brazing assembly.

7. The application of the brazing auxiliary slurry as recited in claim 6, wherein a water spraying device (3) is adopted to spray water on the surface of the joint position, the water spraying device (3) comprises a support frame (36) and a water collecting tank (31) fixedly connected to the support frame (36), a water suction pump (32) is fixedly connected to the water collecting tank (31), a water spraying pipe (33) is fixedly connected to the water suction pump (32), an atomizing nozzle (34) is fixedly connected to the water spraying pipe (33), the atomizing nozzle (34) is communicated with the water spraying pipe (33), and the atomizing nozzle (34) is positioned right above the joint position of the brazing assembly (1); the support frame (36) is fixedly connected with a water collecting tank (35), a water leakage hole (354) is formed in the water collecting tank (35), the water leakage hole (354) is located right above the joint position of the brazing assembly (1), the width of the water leakage hole (354) is the same as that of the joint position of the brazing assembly (1), and water sprayed out of the atomizing spray head (34) penetrates through the water leakage hole (354) and contacts with the joint position of the brazing assembly (1).

8. Use of a brazing aid slurry according to claim 7, wherein said atomizer (34) is provided in a plurality, and wherein said plurality of atomizers (34) is arranged along the direction of movement of the brazing assembly (1).

Technical Field

The application relates to the field of brazing, in particular to a preparation method of brazing aid slurry, the brazing aid slurry and application thereof.

Background

The soldering assistant slurry is a slurry liquid mixture formed by mixing soldering assistant adhesive and soldering assistant powder; before the heating process in the brazing process, the brazing auxiliary agent slurry is coated on a welding interface through coating equipment and then is heated; in the front section of the heating process, the adhesive in the brazing slurry volatilizes or burns to leave the welding interface, and the brazing auxiliary agent is left; the brazing aid provides a brazing aid during subsequent heating.

The brazing auxiliary agent slurry can be matched with a plurality of automatic coating devices to realize quantitative, high-speed and high-stability coating of brazing materials, so that an automatic production line can be better matched.

However, in the coating process, in order to enable more precise control, particularly to enable a smaller lower limit of the coating amount, it is necessary to reduce the viscosity of the slurry as much as possible; at the same time, it is also desirable to reduce the viscosity as much as possible in order to avoid clogging of the coating lines; however, the slurry of the soldering aid coated by reducing the viscosity is easy to generate disordered flow, and then the phenomena of overflow, overflow and the like are easy to occur; the overflow and overflow of the brazing assistant slurry have a destructive effect on the brazing result, and the brazing assistant property is liable to be insufficient, thereby easily causing various brazing defects, and also causing problems of poor appearance and environmental pollution in operation.

In order to solve this problem, it is urgently required to provide a brazing aid slurry which has good fluidity during coating and is easy to coat, and after coating is finished, disordered flow is not easy to occur at the coating position.

Disclosure of Invention

In order to prepare brazing auxiliary agent slurry for brazing, which has the advantages of good fluidity and easiness in coating in the coating process, and disordered flow is not easy to occur at the coating position after the coating is finished, the application provides a preparation method of the brazing auxiliary agent slurry, the brazing auxiliary agent slurry and application thereof.

In a first aspect, the present application provides a method for preparing a brazing assistant slurry, which adopts the following technical scheme:

a method for preparing a brazing assistant slurry, comprising the steps of:

s1, weighing cellulose and water in a weight ratio of 1:20-100, dissolving the cellulose in the water and not dissolving the cellulose in alcohol, and stirring until the cellulose is dissolved to obtain a mixed solution;

s2, weighing the mixed solution and alcohol according to the weight ratio of 1:5-100, stirring and distilling to obtain a mixture;

s3, weighing the mixture and the soldering flux powder according to the weight ratio of 1:1, and stirring to obtain the finished soldering flux slurry.

By adopting the technical scheme, the cellulose which is soluble in water and insoluble in alcohol is firstly put into water for dissolving, and the prepared mixed solution has better viscosity; then mixing with alcohol, because the cellulose is insoluble in alcohol, water in the mixed solution is gradually extracted by the alcohol, so that the cellulose in the mixed solution is gradually separated out to form particles; the cellulose particles form cellulose particles with extremely small granularity under the shearing action of external force by matching with stirring operation, and the cellulose particles are uniformly dispersed in the mixture; the water in the mixture is removed by matching with the distillation operation, the mixture gradually becomes a suspension of cellulose particles dispersed in alcohol along with the loss of the water, the thickening effect of the cellulose basically disappears, the viscosity of the mixture is reduced, and the finished brazing auxiliary agent slurry has good fluidity and is easy to coat.

After the brazing auxiliary agent slurry is coated on the joint position of the brazing assembly, moisture in the external environment and moisture added by external force can be absorbed by using the moisture absorption effect of alcohol substances, so that the local water content on the surface of the brazing auxiliary agent slurry is improved, and cellulose particles can quickly absorb water to dissolve and improve the viscosity, so that a cellulose particle aqueous solution with very high viscosity is formed on the local surface of the brazing auxiliary agent slurry; because the local viscosity of the brazing aid slurry is very high, and the cellulose particles are matched with the extremely small fluidity, the cellulose particles in the mixture form a layer of high-viscosity diaphragm which plays a role of a 'solidified' coating on the surface of the brazing aid slurry.

By utilizing the better stability of the diaphragm, the sagging property of the brazing auxiliary agent slurry at the joint position of the brazing assembly is improved to some extent, so that the finished brazing auxiliary agent slurry has the advantage of being difficult to generate disordered flowing after being coated.

Preferably, the alcohol is added to the mixed solution at a flow rate of 0.2-5g/s, and the stirring speed is 500-1200 r/min.

By adopting the technical scheme, the cellulose particles with good dispersion effect are formed by limiting the adding speed and the stirring speed of the alcohol, and after the cellulose particles are coated on the joint position, a compact diaphragm is formed on the surface of the brazing auxiliary agent slurry by utilizing the good dispersion effect of the cellulose particles, so that the disordered flow of the brazing auxiliary agent slurry at the joint position after the coating is finished is further prevented.

If the flow rate of the added alcohol is too low, the formed cellulose particles are easy to be too small, and the diaphragm formed by the too small cellulose particles after moisture absorption is thinner and weaker in strength, so that the soldering assistant slurry is easy to flow out of order at the joint position after being coated; if the flow velocity is too high, the local alcohol concentration is easily too high, and cellulose molecules are separated out too much instantly, so that agglomeration is easily formed, the granularity of cellulose particles is larger, larger cellulose particles are not easy to form a diaphragm, and disordered flow is easily generated at the position of a joint after the brazing auxiliary agent slurry is coated; therefore, the flow rate is controlled to be 0.2-5g/s, a compact diaphragm can be formed on the surface of the brazing assistant slurry, and disordered flowing at the joint position after the coating of the brazing assistant slurry is finished can be further prevented.

If the stirring speed is too low, the local concentration is easy to be instantly increased after the alcohol is added, so that the cellulose molecule precipitation speed is accelerated, and the cellulose particle granularity is easy to be larger; if the stirring speed is too high, cellulose molecules are easily damaged; therefore, the stirring speed is limited to 500-1200r/min, the diaphragm is ensured to be formed, and the formed diaphragm has better compactness, so that disordered flowing at the position of the joint after the injection of the brazing auxiliary agent slurry is further prevented.

Preferably, the cellulose is selected from one or more of hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.

By adopting the technical scheme, the prepared brazing auxiliary agent slurry has low viscosity and is easy to coat by utilizing the good water solubility and alcohol insolubility of cellulose; after the coating is finished, the cellulose particles have better water solubility, and the cellulose particles are easy to form a diaphragm with better viscosity after being contacted with water molecules, so that the diaphragm is stably attached to the surface of brazing auxiliary agent slurry, the brazing auxiliary agent slurry on a brazing assembly is difficult to flow on the brazing assembly, and the diaphragm has good constraint performance on the brazing auxiliary agent slurry.

Preferably, the alcohol is one or more of propylene glycol, glycerol, butanediol, n-butanol and hexanediol.

By adopting the technical scheme, the boiling points of the propylene glycol, the glycerol, the butanediol, the n-butanol, the hexanediol and the like are all larger than that of water, so that the distillation of water is facilitated; the cellulose particles are gradually formed along with the gradual reduction of the water content, and the viscosity of the mixture is gradually reduced, so that the finished soldering flux slurry has good fluidity and is convenient to coat.

After the brazing auxiliary agent slurry is coated on the joint position, cellulose particles on the surface of the brazing auxiliary agent slurry are in contact with water molecules by utilizing the good moisture absorption of alcohol substances on the surface of the brazing auxiliary agent slurry, the cellulose particles gradually expand in volume after meeting water, and the viscosity is gradually improved, so that the generation of a diaphragm on the surface of the brazing auxiliary agent slurry is promoted, and the brazing auxiliary agent slurry is not easy to flow out of order after being coated on the joint position.

In a second aspect, the present application provides a brazing assistant slurry, which adopts the following technical scheme:

a brazing aid slurry is prepared by a method for preparing a brazing aid slurry.

By adopting the technical scheme, the prepared brazing auxiliary agent slurry can be used in the field of brazing, and the good fluidity of the brazing auxiliary agent slurry is utilized in the coating process, so that an injection pipeline is not easy to block; after the coating is finished, the brazing auxiliary agent slurry forms a diaphragm on the surface of the brazing auxiliary agent slurry under the matching action of moisture, so that the brazing auxiliary agent slurry is not easy to flow out of order at the position of a joint after the coating is finished.

In a third aspect, the present application provides an application of a brazing assistant slurry for brazing, which adopts the following technical scheme:

use of a brazing aid slurry comprising the steps of:

and (3) coating the brazing auxiliary agent slurry on the position of the welding joint of the welded material, and spraying water on the position of the joint after coating to obtain the finished brazing assembly.

By adopting the technical scheme, after the small water drops of atomized water are sprayed to the joint position of the welded material, the volume of the alcohol substance in the brazing auxiliary agent slurry is accelerated to expand by utilizing the moisture absorption effect of the alcohol substance in the brazing auxiliary agent slurry, so that the cellulose particles are further promoted to absorb water and dissolve, and the diaphragm is quickly formed on the surface of the brazing auxiliary agent slurry at the joint position of the welded material; the diaphragm has good compactness, certain elasticity and toughness, and can better prevent the disordered flowing of the brazing auxiliary agent slurry at the joint position.

Preferably, a water spraying device is adopted to spray water on the surface of the seam position, the water spraying device comprises a support frame and a water collecting tank fixedly connected on the support frame, a water suction pump is fixedly connected on the water collecting tank, a water spraying pipe is fixedly connected on the water suction pump, an atomizing nozzle is fixedly connected on the water spraying pipe and communicated with the water spraying pipe, and the atomizing nozzle is positioned right above the seam position of the brazing assembly; the support frame is fixedly connected with a water collecting tank, the water collecting tank is provided with a water leakage hole, the water leakage hole is positioned right above the seam position of the brazing assembly, the width of the water leakage hole is the same as that of the seam position of the brazing assembly, and water sprayed by the atomizing spray head penetrates through the water leakage hole to contact with the seam position of the brazing assembly.

Through adopting above-mentioned technical scheme, in pouring into the water-collecting tank with water, the moisture of suction pump in with the water-collecting tank is taken out to the spray pipe in, the atomizer on the utilization spray pipe is with the seam position department surface of moisture spraying subassembly of brazing, moisture passes the hole that leaks on the water catch bowl and falls to the subassembly seam position department of brazing, the perpendicular decurrent moisture of atomizer spun falls to the seam position department of subassembly of brazing promptly, and the atomizer is collected by the water catch bowl towards the unnecessary moisture of spraying all around, prevent atomizer spun moisture to fall to the subassembly of brazing non-seam position department.

After the brazed assembly is machined and formed, the brazed assembly can be stacked, and if moisture exists at the position, which is not a joint, on the surface of the brazed assembly, the surface of the brazed assembly is easy to mildew, so that the machining performance and the service life of the brazed assembly are influenced; therefore, the water collecting tank, the water leakage holes and the water spraying pipe are matched, so that the surface of the brazing auxiliary agent slurry at the joint position of the brazing assembly is in contact with water, the formation of a diaphragm on the surface of the brazing auxiliary agent slurry is promoted, and the brazing auxiliary agent slurry is not easy to flow out of order after being dispensed to the joint position of the brazing assembly; and no moisture adheres to the positions of the surface dispensing positions of the brazing assemblies, so that the finished products have good processing quality and performance.

Preferably, the atomizing nozzles are provided with a plurality of atomizing nozzles, and the plurality of atomizing nozzles are arranged along the movement direction of the brazing assembly.

By adopting the technical scheme, the plurality of atomizing nozzles are utilized to spray water to the seam position of the brazing assembly, atomized water drops are uniformly contacted with the surface of the brazing auxiliary agent slurry, the film forming speed is ensured, and meanwhile, the film forming density of the surface of the brazing auxiliary agent slurry is further ensured, so that the brazing auxiliary agent slurry is not easy to flow out of order at the seam position.

In summary, the present application has the following beneficial effects:

1. the cellulose, the water and the alcohol are sequentially stirred, mixed and matched with the distillation operation, so that the viscosity of the brazing auxiliary agent slurry is low, the brazing auxiliary agent slurry has better fluidity, the brazing auxiliary agent slurry is easy to coat, and the lower limit of the coating amount is further reduced; after the brazing auxiliary agent slurry is coated on the joint position of the brazing assembly, a diaphragm with certain elasticity is formed on the surface of the brazing auxiliary agent slurry on the joint position of the brazing assembly by utilizing the moisture absorption effect of the alcohol substance, and the brazing auxiliary agent slurry on the joint position is not easy to flow disorderly by utilizing the blocking effect and the better stability of the diaphragm, namely the brazing auxiliary agent slurry is better in fluidity and easy to coat in the coating process, and is not easy to flow disorderly at the joint position after the coating is finished.

2. The flow rate and the stirring speed of the alcohol are limited, so that the formed diaphragm is stable and compact, and disordered flowing at the position of a joint after the coating of the brazing assistant slurry can be further prevented.

3. After the brazing auxiliary agent slurry on the surface of the welded material is contacted with the atomized water drops, the moisture absorption effect of alcohol substances in the brazing auxiliary agent slurry is utilized to further promote the dissolution of cellulose particles in the brazing auxiliary agent slurry, so that the brazing auxiliary agent slurry on the surface of the welded material quickly forms a diaphragm, and the disordered flowing of the brazing auxiliary agent slurry at the joint position after the coating is finished is further prevented.

4. The water collecting tank, the water leakage holes and the water spraying pipe are matched, and water is prevented from being sprayed to other positions of the brazing assembly except the joint position as far as possible, so that the surface of the brazing assembly is free of moisture adhesion except the joint position, and the finished product is guaranteed to have good processing quality and performance.

Drawings

FIG. 1 is a schematic structural view of a brazed assembly in an application example of the present application;

FIG. 2 is a schematic view of a water spraying apparatus according to an embodiment of the present application;

FIG. 3 is a schematic illustration of an embodiment of a sump in accordance with an application of the present application;

fig. 4 is an enlarged view of a portion a of fig. 3.

In the figure: 1. brazing the assembly; 11. aluminum alloy plate; 12. a brazing aid slurry; 2. a support table; 21. a baffle plate; 22. a conveyor belt; 3. a water spraying device; 31. a water collection tank; 32. a water pump; 33. a water spray pipe; 34. an atomizing spray head; 35. a water collection tank; 351. a small groove; 352. a large groove; 353. a support bar; 354. a water leakage hole; 36. a support frame.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples.

Examples

Flux powder was purchased from Solvay corporation, germany, model 2805; other raw materials and equipment are all sold in the market.

Example 1: a method for preparing brazing assistant slurry comprises the following steps:

s1, weighing 1kg of hydroxypropyl methyl cellulose, placing the hydroxypropyl methyl cellulose in 4kg of absolute ethyl alcohol, performing ultrasonic dispersion for 3min under the condition of 20kHz, then adding 20kg of water, mixing, and stirring for 8h at the rotating speed of 300r/min to obtain a mixed solution;

s2, weighing 5kg of glycerol, placing the glycerol into the mixed solution prepared in the S1, adding the glycerol into the mixed solution under the conditions that the flow rate is 0.2g/S and the stirring speed is 500r/min, and distilling the mixture at the temperature of 80 ℃ until the viscosity is not reduced any more to prepare a mixture;

s3, weighing 10kg of the mixture, mixing the mixture with 10kg of the soldering flux powder, and stirring the mixture for 30min at the rotating speed of 500r/min to obtain the finished soldering flux slurry.

Example 2: a method for preparing brazing assistant slurry comprises the following steps:

s1, weighing 1kg of hydroxyethyl cellulose, placing the hydroxyethyl cellulose in 4kg of absolute ethyl alcohol, performing ultrasonic dispersion for 3min under the condition of 20kHz, then adding 40kg of water, mixing, and stirring for 7h at the rotating speed of 300r/min to obtain a mixed solution;

s2, weighing 30kg of butanediol, placing the butanediol into the mixed solution prepared in the S1, adding the butanediol into the mixed solution under the conditions that the flow rate is 1g/S and the stirring speed is 800r/min, and distilling at 80 ℃ until the viscosity is not reduced any more to prepare a mixture;

s3, weighing 10kg of the mixture, mixing the mixture with 10kg of the soldering flux powder, and stirring the mixture for 30min at the rotating speed of 500r/min to obtain the finished soldering flux slurry.

Example 3: a method for preparing brazing assistant slurry comprises the following steps:

s1, weighing 1kg of hydroxymethyl cellulose, placing the hydroxymethyl cellulose in the mixed solution prepared in the S1, performing ultrasonic dispersion for 3min under the condition of 20kHz, adding 55kg of water, mixing, and stirring for 6h at the rotating speed of 300r/min to prepare the mixed solution;

s2, weighing 65kg of propylene glycol, placing the propylene glycol into the mixed solution prepared in the S1, adding the propylene glycol into the mixed solution under the conditions that the flow rate is 3g/S and the stirring speed is 1000r/min, and distilling at the temperature of 80 ℃ until the viscosity is not reduced any more to prepare a mixture;

s3, weighing 10kg of the mixture, mixing the mixture with 10kg of the soldering flux powder, and stirring the mixture for 30min at the rotating speed of 500r/min to obtain the finished soldering flux slurry.

Example 4: a method for preparing brazing assistant slurry comprises the following steps:

s1, weighing 1kg of carboxymethyl cellulose, placing the carboxymethyl cellulose in 4kg of absolute ethyl alcohol, performing ultrasonic dispersion for 3min under the condition of 20kHz, then adding 100kg of water, mixing, and stirring for 6h at the rotating speed of 300r/min to obtain a mixed solution;

s2, weighing 100kg of n-butanol, putting the n-butanol into the mixed solution prepared in the S1, adding the n-butanol into the mixed solution under the conditions that the flow rate is 5g/S and the stirring speed is 1200r/min, and distilling at the temperature of 80 ℃ until the viscosity is not reduced any more to prepare a mixture;

s3, weighing 10kg of the mixture, mixing the mixture with 10kg of the soldering flux powder, and stirring the mixture for 30min at the rotating speed of 500r/min to obtain the finished soldering flux slurry.

Example 5: the present embodiment is different from embodiment 3 in that:

s2, weighing 65kg of propylene glycol, adding the propylene glycol into 1kg of mixed solution at one time, and stirring for 5min at the speed of 1000r/min after the addition is finished to obtain a mixture.

Example 6: the present embodiment is different from embodiment 3 in that:

s1, weighing 1kg of hydroxymethyl cellulose, adding 55kg of water, mixing, and stirring at the rotating speed of 300r/min for 6h to obtain a mixed solution.

Application example

Aluminum alloy plates in the following raw materials are purchased from 2024 hard aluminum plates manufactured by Shandong Huanhai aluminum industry Co Ltd; other raw materials and equipment are all sold in the market.

Application example 1: use of a brazing aid slurry for brazing:

the brazing auxiliary slurry prepared in example 3 was injected into an injection tube, the injection needle was connected to the injection tube, the brazing auxiliary slurry was injected to the position of the welded joint of the aluminum alloy plate using the injection needle, after the injection was completed, a water jet gun was used to spray water at the position of the joint, the distance between the muzzle of the water jet gun and the surface of the welded joint of the aluminum alloy plate was 40cm, and the moving speed of the aluminum alloy composite plate to which the brazing auxiliary slurry was dispensed was 200m/min, to obtain a finished brazed assembly.

Application example 2: the present application example is different from application example 1 in that:

and a water spraying device is adopted to spray water at the joint position.

Referring to fig. 1, two ends of an aluminum alloy plate 11 are bent, a brazing aid slurry 12 prepared in example 3 is dispensed at a butt joint position, the two ends of the aluminum alloy plate 11 are connected together by the brazing aid slurry 12 to prepare a brazed assembly 1, and the contact position surfaces of the brazing aid slurry 12 and the two ends of the aluminum alloy plate 11 are the joint positions of the brazed assembly.

Referring to fig. 1 and 2, two baffles 21 are fixedly connected to the support platform 2, a conveyor belt 22 is arranged between the two baffles 21, the brazing assembly 1 is positioned on the conveyor belt 22 and moves along the length direction of the brazing assembly 1, and the length direction of the brazing assembly 1 is the same as that of the baffles 21; one baffle plate 21 is provided with a water spraying device 3, and the water spraying device 3 sprays water towards the surface of the brazing auxiliary agent slurry 12 on the surface of the brazing assembly 1; the water spraying device 3 sprays water to the surface of the brazing assembly 1 in the conveying process of the brazing assembly 1, and after atomized water is contacted with the surface of the brazing auxiliary agent slurry 12, a diaphragm is formed on the surface of the brazing auxiliary agent slurry 12, so that the brazing auxiliary agent slurry 12 is not easy to flow on the surface of the brazing assembly 1.

Referring to fig. 3 and 4, the water spraying device 3 includes a support frame 36 fixedly connected to the top of the baffle 21 and a water collecting tank 31 fixedly connected to the support frame 36, a water suction pump 32 is fixedly connected to the water collecting tank 31, a water spray pipe 33 is fixedly connected to the water suction pump 32, the water spray pipe 33 is communicated with the water collecting tank 31, 10 atomizing spray heads 34 are fixedly connected to the water spray pipe 33, the 10 atomizing spray heads 34 are arranged along the length direction of the brazing assembly 1, the 10 atomizing spray heads 34 are all communicated with the water spray pipe 33, the 10 atomizing spray heads 34 are all located right above the brazing auxiliary slurry 12 on the brazing assembly 1, and the distance between the atomizing spray heads 34 and the surface of the brazing auxiliary slurry 12 is 40 cm; spraying 10 atomizing nozzles 34 to the brazing auxiliary agent slurry 12 on the surface of the brazed assembly 1 in a progressive manner to accelerate the formation of the diaphragm; the atomizer 34 is an ultrasonic atomizer.

Referring to fig. 3 and 4, the support frame 36 is fixedly connected with the water collection tank 35, the top of the water collection tank 35 is fixedly connected with two support rods 353, the two support rods 353 are both vertically arranged, the two support rods 353 are arranged along the length direction of the brazing assembly 1, and the water spray pipe 33 is fixedly connected with the two support rods 353; the water collecting tank 35 is positioned between the water spraying pipe 33 and the brazing assembly 1, a water leakage hole 354 is formed in the water collecting tank 35, the water leakage hole 354 is positioned right above the brazing auxiliary agent slurry 12, the width of the water leakage hole 354 is the same as that of the brazing auxiliary agent slurry 12, the length of the water leakage hole 354 is parallel to the length direction of the brazing assembly 1, and water sprayed out of the atomizing nozzle 34 penetrates through the water leakage hole 354 to be in contact with the surface of the brazing auxiliary agent slurry 12; the water collecting tank 35 is used for collecting the excessive moisture sprayed by the atomizing spray head 34, so that the vertically downward moisture sprayed by the atomizing spray head 34 is connected with the surface of the brazing auxiliary agent slurry 12, the moisture at other positions is blocked in the water collecting tank 35, and the influence on the processing performance and the service life of a finished product caused by the moisture attached to other positions on the surface of the brazing assembly 1 is avoided.

Referring to fig. 3 and 4, the water collecting tank 35 includes two large tanks 352 and two small tanks 351, the water leakage hole 354 is located between the two large tanks 352, two sides of the water leakage hole 354 are respectively provided with one large tank 352 and one small tank 351, the large tank 352 is fixedly connected with the small tank 351 adjacent to the large tank 352, and the plane where the bottom of the small tank 351 is located above the plane where the bottom of the large tank 352 is located; through the setting that advances gradually of big groove 352 and little groove 351, not only be convenient for collect atomizer 34 spun moisture, utilize little groove 351 to compare in the great height of big groove 352 moreover, the operating personnel of being convenient for observe the spraying condition of brazing auxiliary agent thick liquid 12 surface atomized water on the subassembly 1 of brazing, guarantee that the finished product surface removes the no moisture of brazing auxiliary agent thick liquid 12 position department and adheres to guarantee off-the-shelf machining performance and life.

The water spraying device 3 implements the principle that after the brazing assembly 1 is bent and the brazing auxiliary agent slurry 12 is dispensed, the brazing assembly 1 moves on the surface of the conveyor belt 22 in the direction close to the water spraying device 3, the water pump 32 pumps water in the water collecting tank 31 into the water spraying pipe 33, the plurality of atomizing nozzles 34 spray the water in the water spraying pipe 33, part of sprayed atomized water flows down to the surface of the brazing auxiliary agent slurry 12 of the brazing assembly 1 through the water leakage holes 354, and other water is collected by the water collecting tank 35.

Application example 3: the present application example is different from application example 2 in that:

the brazing aid slurry prepared in example 1 was used.

Application example 4: the present application example is different from application example 2 in that:

the brazing aid slurry prepared in example 2 was used.

Application example 5: the present application example is different from application example 2 in that:

the brazing aid slurry prepared in example 4 was used.

Comparative example

Comparative example 1: this comparative example differs from example 3 in that:

s2, weighing 65kg of water, putting the water into the mixed liquid prepared in the S1, and adding the water into the mixed liquid under the conditions that the flow rate is 3g/S and the stirring speed is 1000r/min to prepare a mixture.

Comparative example 2: the present embodiment is different from embodiment 3 in that:

100kg of epoxy resin is weighed and placed in 100kg of acetone, 10kg of ethylenediamine, 10kg of polyacrylamide and 2kg of ethylene glycol are added and mixed, and the mixture is mixed and stirred for 20min at the rotating speed of 500r/min to prepare the finished brazing assistant slurry.

Comparative example 3: this comparative example differs from example 3 in that:

s1, weighing 1kg of ethyl cellulose and 55kg of water, mixing, and stirring at the rotating speed of 300r/min for 6h to obtain a mixed solution.

Comparative example 4: the comparative example differs from application example 2 in that:

i, injecting the brazing auxiliary agent slurry prepared in the embodiment 3 into an injection pipe, wherein an injection needle is communicated with the injection pipe, injecting the brazing auxiliary agent slurry into the position of a welding joint of an aluminum alloy plate by using the injection needle, and after the injection is finished, placing the aluminum alloy plate under the condition that the relative humidity is 65% to prepare a finished brazing assembly.

Comparative example 5: the comparative example differs from application example 2 in that:

i, injecting the brazing auxiliary agent slurry prepared in the embodiment 3 into an injection pipe, wherein an injection needle is communicated with the injection pipe, injecting the brazing auxiliary agent slurry into the position of a welding joint of an aluminum alloy plate by using the injection needle, and after the injection is finished, placing the aluminum alloy plate under the condition that the relative humidity is 50% to prepare a finished brazing assembly.

Performance test

1. Viscosity detection

Preparing a mixture by the preparation methods of examples 1-6 and comparative examples 1 and 3, respectively, and preparing a finished brazing assistant slurry by the preparation methods of examples 1-6 and comparative examples 1-3; the viscosity of the mixture and the viscosity of the brazing aid slurry are respectively detected by adopting GB/T2794-2013 brazing aid slurry viscosity measurement and a single-cylinder rotational viscometer method, the mixture and the brazing aid slurry are placed in a constant temperature box at 20 ℃ for 2 hours, then an NDJ-1 viscometer is used for measuring the rotation speed of 6r/s, a No. 3 rotor is selected as the rotor, and viscosity data are recorded.

2. Particle size detection

The preparation methods of examples 1 to 6 were respectively adopted to prepare brazing auxiliary agent slurries, and in the preparation process, the prepared mixtures were samples to be tested, and the particle sizes of the cellulose particles in the samples were detected by a laser particle size shape analyzer, which was purchased from the great chang huajia group, model S3500 series, basic model, wet measurement range 0.70-1000 μm, and the particle sizes of the cellulose particles were recorded by taking the particle sizes of the distribution peaks by a wet injection system at 25 ℃ and 70% humidity.

3. Anti-flow detection

The brazing aid slurries were prepared by the preparation methods of examples 1 to 6 and comparative examples 1 to 3, respectively, the wet film thicknesses were measured by the method for evaluation of sag resistance of the GB/T9264 to 2012 color paints and varnishes, a water spray device was installed above the sag tester, after the sag tester was knife-coated, the wet films were sprayed with water immediately by the water spray device of application example 2 for a period of 2 seconds, and then the wet film thicknesses of examples 1 to 6 and comparative examples 1 to 5 were recorded.

TABLE 1 Performance test Table

As can be seen by combining examples 1 to 4 and table 1, the viscosity of the mixture is affected by the addition of different raw materials, the viscosity of the prepared mixture is relatively low, the fluidity is relatively good, the brazing assistant slurry has relatively good fluidity even after the brazing assistant powder is added, and the phenomenon of pipe blockage is not easily generated in the process of injecting the brazing assistant slurry; and the difference of the adding speed of the alcohol substances has influence on the granularity and the size of the finished cellulose particles; meanwhile, a water spraying device is adopted to spray water on the surface of the brazing aid slurry, so that the wet film thickness is good, and the sagging resistance is good if the wet film thickness is large.

As can be seen by combining example 3 with examples 5-6 and by combining Table 1, both the mixture and the brazing aid slurry prepared in example 5 have better flow properties, allowing easy application of the finished brazing aid slurry.

While the particle size of the cellulose particles in the mixture of example 5 is significantly larger than that of example 3, the wet film thickness of example 5 is significantly lower than that of example 3; the cellulose particles are not easy to form cellulose particles with small granularity by adding the propylene glycol at one time, and water molecules are not easy to dissolve the cellulose particles even if the cellulose particles with large granularity are contacted with moisture sprayed by a water spraying device, so that a diaphragm is not easy to form on the surface of the brazing auxiliary agent slurry; the poor diaphragm forming effect leads to poor sagging resistance of the finished brazing additive slurry after coating, so that the brazing additive slurry is easy to flow disorderly after coating.

Example 6 in the process of preparing the brazing aid slurry, hydroxymethyl cellulose is directly added into water and stirred and mixed, compared with example 3, the viscosity of the mixture and the brazing aid slurry in example 6 is higher than that of the mixture and the brazing aid slurry corresponding to example 3, the granularity of example 6 is larger than that of example 3, and the wet film thickness of example 6 is smaller than that of example 3; it is shown that, in the process of dissolving cellulose, if cellulose is directly mixed with water without dispersion treatment, the cellulose is easy to form a soluble mass, the outer surface of the soluble mass is a high-viscosity solution, but the inside is a large amount of dry cellulose powder which is not contacted with water, so that the viscosity of the mixture and the brazing aid slurry is influenced, the larger cellulose soluble mass is not easy to form smaller cellulose particles, and after the prepared brazing aid slurry is coated on a joint position, the larger cellulose particles in the brazing aid slurry are not easy to absorb moisture to form a diaphragm, so that disordered flowing is easy to occur after the brazing aid slurry is coated.

Combining example 3 and comparative examples 1-5 and table 1, it can be seen that the raw material of comparative example 1 is replaced by the same mass of water for propylene glycol, and the viscosity of the mixture and brazing assistant slurry of comparative example 1 is greater than that of the mixture and brazing assistant slurry corresponding to example 3; the viscosity of the mixture and the viscosity of the finished brazing aid are influenced by increasing the viscosity of the water-soluble hydroxymethyl cellulose only by using water as a solvent and without distillation operation, so that the brazing aid slurry is not easy to coat, and the phenomenon of pipe blockage is easy to occur.

Comparative example 2 selects epoxy resin to prepare brazing auxiliary agent slurry, compared with example 3, the brazing auxiliary agent slurry prepared in comparative example 2 has higher viscosity, which shows that the fluidity is inferior to that of example 3, so that the brazing auxiliary agent slurry is not easy to coat; and the wet film thickness is smaller than that of example 3, which shows that the brazing aid slurry prepared from the epoxy resin has better sag resistance, and the comparison between example 3 and comparative example 2 shows that the brazing aid slurry prepared by the method has the advantages of better fluidity, easy coating and difficult disordered flowing after the coating is finished.

Comparative example 3 in the process of preparing the brazing aid slurry, hydroxyethyl cellulose is adopted to be respectively mixed with water and alcohol, compared with example 3, the viscosity of the mixture and the brazing aid slurry prepared in the comparative example 3 is larger than that of the mixture and the brazing aid slurry corresponding to the example 3, and the wet film thickness is obviously lower than that of the example 3; the hydroxyethyl cellulose is dissolved in alcohol and is insoluble in water, even if the cellulose is subjected to water spraying treatment by a water spraying device, a diaphragm cannot be formed on the surface of the brazing auxiliary agent slurry, and the sagging resistance of the cellulose is maintained only by the viscosity of the cellulose; the method comprises the steps of preparing brazing auxiliary agent slurry by using cellulose which is soluble in water and insoluble in alcohol, and after the brazing auxiliary agent slurry is coated, forming a diaphragm on the surface of the brazing auxiliary agent slurry through the water spraying effect of a water spraying device, so that the coated brazing auxiliary agent slurry is not easy to flow disorderly.

Comparative example 4 after dispensing the brazing aid slurry, the brazed assembly was placed under a relative humidity of 65% without water spraying by a water spraying device, and the wet film thickness of comparative example 4 was significantly lower than that of example 3, compared to example 3; the water spraying effect of the water spraying device is explained, the formation of the diaphragm on the surface of the brazing auxiliary agent slurry can be effectively promoted, compared with moisture in a humidity environment, the formation of the diaphragm is promoted, the formation of the compact diaphragm is realized, and the situation that the brazing auxiliary agent slurry flows disorderly after being coated is not easy to occur.

Comparative example 5 after the brazing aid slurry was applied by dispensing, the brazed assembly was left under a condition of 50% relative humidity without water spraying by a water spraying device, and it was demonstrated that moisture under a suitable humidity environment can promote the formation of a diaphragm on the surface of the brazing aid slurry applied thereto, but the water spraying operation can further promote the formation of a diaphragm on the surface of the brazing aid slurry applied thereto, whereas the surface of the brazed assembly is not likely to form a diaphragm after the brazing aid slurry is applied thereto under a condition of 50% relative humidity or less, and the brazing aid slurry not likely to form a diaphragm is likely to flow out of order after the application is completed.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.