阅读说明：本技术 一种测量铝合金复合箔的方法 (Method for measuring aluminum alloy composite foil ) 是由 曹琦 赵娜 刘二磊 习博建 张斌 周德敬 于 2021-07-14 设计创作，主要内容包括：本申请提供一种测量铝合金复合箔的方法,具体涉及铝合金复合箔技术领域。一种测量铝合金复合箔的方法,包括：获取测量样片；将所述测量样片悬挂于钎焊室中；在预定钎焊工艺下,对测量样片进行钎焊处理；对钎焊后的测量样片进行腐蚀处理；确定样片熔蚀最严重的区域；根据所述熔蚀最严重的区域确定熔蚀度。该方法制样方便、操作简单,对铝合金复合箔的测量标准明确。(The application provides a method for measuring an aluminum alloy composite foil, and particularly relates to the technical field of aluminum alloy composite foils. A method of measuring an aluminum alloy composite foil, comprising: obtaining a measurement sample wafer; suspending the measurement sample wafer in a brazing chamber; carrying out brazing treatment on the measurement sample wafer under a preset brazing process; carrying out corrosion treatment on the brazed measurement sample wafer; determining the most serious area of the sample wafer; and determining the ablation degree according to the region with the most severe ablation. The method has the advantages of convenient sample preparation, simple operation and definite measurement standard of the aluminum alloy composite foil.)

1. A method of measuring an aluminum alloy composite foil, comprising:

obtaining a measurement sample wafer;

placing the measurement sample wafer in a brazing chamber;

carrying out brazing treatment on the measurement sample wafer under a preset brazing process;

carrying out corrosion treatment on the brazed measurement sample wafer;

determining the most serious area of the sample wafer;

and measuring the erosion degree of the sample wafer according to the area with the most serious erosion.

2. The method of claim 1, wherein the brazing process comprises:

raising the temperature of the ablation chamber from room temperature to 490-510 ℃ within 12-15 min;

the temperature of the ablation chamber is increased from 490-510 ℃ to 570-580 ℃ within 6-8 min;

the temperature of the ablation chamber is increased from 570-580 ℃ to 595-610 ℃ within 2-2.5 min;

keeping the temperature of the ablation chamber at 595-610 ℃ for 4-6 min.

3. The method of claim 1,

the corrosion treatment comprises the following steps:

and (4) embedding the brazed sample wafer, grinding the sample wafer again, and corroding the sample wafer by using a corrosion reagent.

4. The method of claim 3, wherein the setting comprises:

cutting the sample piece subjected to simulated brazing to be used as a sample piece to be observed, polishing, putting the polished surface downwards into an inlaying machine, and adding bakelite powder to carry out inlaying;

preferably, the damascene parameters include:

pressure: 230 to 250Bar, and the balance weight of the alloy,

heating temperature: 170-190 ℃,

heating time: the time for which the reaction is carried out is 4-5 min,

cooling time: 4-5 min.

5. The method of claim 3, wherein the milling comprises:

polishing by using an automatic polishing machine, and polishing by using an automatic polishing machine;

preferably, the sand paper is used for grinding 320#, 500#, and 1200# in sequence.

6. A method according to claim 1 or 3, wherein the corrosion agent of the corrosion treatment is a kohler reagent;

preferably, the Kohler reagent is a mixed solution of hydrofluoric acid, hydrochloric acid and nitric acid;

more preferably, the ratio of kohler reagent is hydrofluoric acid: hydrochloric acid: nitric acid: water-1: 1.5:2.5: 95.

7. A method according to claim 1 or 3, characterized in that the etching time is 5-15 seconds.

8. The method of claim 1, wherein the areas of the coupon that are most subject to erosion are microscopically identified after the etching process;

and observing the most serious area of the sample wafer in the erosion process, and measuring the erosion degree of the sample wafer.

9. The method of claim 1 or 8, wherein the method of measuring the degree of erosion of the coupon comprises:

determining an ablation site;

judging the depth of the erosion;

and calculating the corrosion resistance grade.

10. The method of claim 9, wherein the method of calculating the corrosion resistance rating comprises:

the sum of the Erosion Score of the Erosion area of the measurement sample is calculated.

Technical Field

The application relates to the technical field of aluminum alloy composite foils, in particular to a method for measuring an aluminum alloy composite foil.

Background

The aluminum alloy composite foil, namely the aluminum foil, is an aluminum coiled material, a strip material or a sheet material with very thin thickness obtained by rolling aluminum and an aluminum alloy plate strip, and the aluminum foil with high strength, high plasticity, high stress resistance and corrosion resistance is suitable for manufacturing fins of a heat exchanger. The composite aluminum foil has the advantages of light weight, corrosion resistance, good brazing performance, reliable performance and the like, and is widely applied to heat exchangers.

The all-aluminizing of heat exchangers has been a necessary trend of development, the manufacture of which is done by brazing. During brazing, the brazing filler metal has a melting point much lower than that of the core material due to the large amount of the melting point reducing element (usually Si element). The brazing temperature is generally above the liquidus of the braze and below the solidus of the base aluminum alloy. During brazing, the brazing filler metal is melted, and the liquid brazing filler metal flows to the lap joint under the action of capillary force to form a firm metallurgical joint. During brazing, the melted brazing filler metal generates a corrosion phenomenon on the core material, the mechanical property of the core material and the fluidity of the liquid brazing filler metal are reduced, and the mechanical property, the corrosion property and the welding effect of a welding product are influenced.

At present, there is no uniform method for evaluating the corrosion degree of the aluminum alloy composite foil in the industry, heat exchanger manufacturers generally intercept partial areas after the welding of the heat exchanger is finished, and observe the corrosion degree of the composite fin Si after sample embedding and sample grinding, different manufacturers have different evaluation standards, some require that the maximum corrosion depth cannot exceed 70%, some cannot exceed 50%, and some require that the average corrosion depth cannot exceed 30%. This method does allow the heat exchanger manufacturer to evaluate the degree of erosion, but is inefficient and costly due to the need to destroy the finished heat exchanger. For manufacturers of aluminum alloy composite foils, the corrosion resistance of the product must be evaluated before the product is supplied to the manufacturers of heat exchangers, so that the degree of corrosion resistance of the product can be grasped in the first place.

At present, aluminum alloy composite foil manufacturers generally do not evaluate the ablation degree, or only observe the appearance after simulated brazing to roughly judge the ablation condition, and do not have quantitative evaluation standards, so that the ablation degree cannot be quantitatively evaluated.

Disclosure of Invention

In order to solve the blank in the field of evaluating the corrosion degree of the aluminum alloy composite foil, the application provides a method for measuring the aluminum alloy composite foil, the method is convenient in sample preparation and clear in evaluation standard.

According to one aspect of the present application, a method of measuring an aluminum alloy composite foil includes:

obtaining a measurement sample wafer;

placing the measurement sample wafer in a brazing chamber;

carrying out brazing treatment on the measurement sample wafer under a preset brazing process;

carrying out corrosion treatment on the brazed measurement sample wafer;

determining the most serious area of the sample wafer;

and measuring the erosion degree of the sample wafer according to the area with the most serious erosion.

According to some embodiments of the application, the brazing process comprises:

raising the temperature of the ablation chamber from room temperature to 490-510 ℃ within 12-15 min;

the temperature of the ablation chamber is increased from 490-510 ℃ to 570-580 ℃ within 6-8 min;

the temperature of the ablation chamber is increased from 570-580 ℃ to 595-610 ℃ within 2-2.5 min;

keeping the temperature of the ablation chamber at 595-610 ℃ for 4-6 min.

According to some embodiments of the application, the etching process comprises:

and (4) embedding the brazed sample wafer, grinding the sample wafer again, and corroding the sample wafer by using a corrosion reagent.

According to some embodiments of the present application, the insert comprises:

cutting the sample piece subjected to simulated brazing to be used as a sample piece to be observed, polishing, putting the polished surface downwards into an inlaying machine, and adding bakelite powder to carry out inlaying;

preferably, the damascene parameters include:

pressure: 230 to 250Bar, and the balance weight of the alloy,

heating temperature: 170-190 ℃,

heating time: the time for which the reaction is carried out is 4-5 min,

cooling time: 4-5 min.

According to some embodiments of the present application, the wear sample comprises:

polishing by using an automatic polishing machine, and polishing by using an automatic polishing machine;

preferably, the sand paper is used for grinding 320#, 500#, and 1200# in sequence.

According to some embodiments of the present application, the etching agent of the etching process is a kohler agent;

preferably, the Kohler reagent is a mixed solution of hydrofluoric acid, hydrochloric acid and nitric acid;

more preferably, the ratio of kohler reagent is hydrofluoric acid: hydrochloric acid: nitric acid: water 1:1.5:2.5: 95;

preferably, the etching time is 5 to 15 seconds.

According to some embodiments of the present application, the areas of the coupon that are most severely eroded are identified under a microscope after the etching process;

and observing the most serious area of the sample wafer in the erosion process, and measuring the erosion degree of the sample wafer.

According to some embodiments of the present application, the method for measuring erosion degree of a sample wafer comprises:

determining an ablation site;

judging the depth of the erosion;

and calculating the corrosion resistance grade.

According to some embodiments of the present application, the method of calculating a corrosion resistance rating includes:

the sum of the Erosion Score of the Erosion area of the measurement sample is calculated.

Compared with the prior art, the beneficial effects of the application comprise one or more of the following:

according to some embodiments, the present application provides a method of measuring an aluminum alloy composite foil, comprising: obtaining a measurement sample wafer; suspending the measurement sample wafer in a brazing chamber; carrying out brazing treatment on the measurement sample wafer under a preset brazing process; carrying out corrosion treatment on the brazed measurement sample wafer; determining the most serious area of the sample wafer; and measuring the erosion degree of the sample wafer according to the area with the most serious erosion. The method is simple to operate, has low requirements on equipment, and has clear evaluation standard on the aluminum alloy composite foil.

According to some embodiments, the method for measuring the aluminum alloy composite foil makes up the blank in the field in this respect, and quantifies the evaluation method of the aluminum alloy composite foil with clear standards.

According to some embodiments, by adopting the method, a manufacturer of the aluminum alloy composite foil (with the thickness of 0.06-0.10mm) can judge the anti-corrosion capability of the product in the use process of the client according to the corrosion degree condition without the need of evaluating by means of resources of the client.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:

FIG. 1 is a schematic illustration of a dailies according to an exemplary embodiment of the present application;

fig. 2 is an erosion degree evaluation reference map according to an exemplary embodiment of the present application;

FIG. 3 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 4 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 5 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 6 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 7 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 8 is a graph comparing erosion levels according to example embodiments of the present application;

FIG. 9 is a schematic illustration of sample erosion according to an example embodiment of the present application;

FIG. 10 is a schematic view of a sampling location according to an exemplary embodiment of the present application;

FIG. 11 is an enlarged schematic view of a sampling area according to an exemplary embodiment of the present application.

Detailed Description

As mentioned above in the background, the phenomenon of corrosion is a critical problem in brazing of aluminium alloys. With the overall aluminization and compaction of the heat exchanger, the requirements on materials are higher and higher, in order to improve the service life and strength of the materials, obtain better brazing effect and further expand the application field of the brazing aluminum alloy materials, the erosion needs to be better controlled, and the influence of the erosion on the materials is avoided to the maximum extent.

At present, some blanks exist in the evaluation of the corrosion degree of the aluminum alloy composite foil, and the application aims to provide the evaluation method of the corrosion degree of the aluminum alloy composite foil.

The application, if the specific conditions are not indicated, is carried out according to the conventional conditions or the conditions suggested by the manufacturer, and the raw materials, auxiliary materials, reagents or instruments used are not indicated by the manufacturer, but are all conventional products which can be obtained by market.

According to the technical concept of the application, the method for measuring the aluminum alloy composite foil is adopted to uniformly evaluate the corrosion degree of the aluminum alloy composite foil in the heat exchanger, the sample preparation is simple and convenient, the evaluation standard is clear and high in efficiency, the finished product of the heat exchanger does not need to be damaged, the corrosion resistance of the product in the use process of a client can be judged according to the corrosion degree condition in an aluminum alloy composite foil manufacturer, and the evaluation is carried out without the help of resources of the client.

The present application is described in detail below.

It should be noted that the parameters such as the number of samples, the size of the samples, the cutting size, and the number of observation areas used in the following examples and test examples are set by matching according to the specifications of the equipment used in the test, and the adjustment of the above data is within the scope of the present application.

According to an exemplary embodiment, the application provides an evaluation method of an aluminum alloy composite foil corrosion degree, which adopts a simulated brazing process, and specifically comprises the following steps:

obtaining a measurement sample wafer;

suspending the measurement sample wafer in a brazing chamber;

carrying out brazing treatment on the measurement sample wafer under a preset brazing process;

carrying out corrosion treatment on the brazed measurement sample wafer;

determining the most serious area of the sample wafer;

and determining the ablation degree according to the region with the most severe ablation.

Fig. 1 is a schematic view of a dailies according to an exemplary embodiment of the present application.

Obtaining measurement sample sheets, taking n sample sheets from each batch of to-be-detected articles, cutting the n sample sheets into a size suitable for a brazing furnace, and then suspending the sample sheets in the prepared brazing furnace; carrying out brazing treatment on the measurement sample wafer under a preset brazing process; after brazing, each sample piece is cut into a size suitable for observation, inserted, ground and corroded by a corrosion reagent.

The sample inlaying method comprises the following steps:

the method comprises the steps of selecting a required cross section by using an automatic inlaying machine, intercepting a sample with a proper size, usually 2cm x 2cm, grinding off some sharp edges and corners of the sample to enable the ground surface to be flat, putting the prepared sample on an ejector rod in an inlaying sample sleeve barrel with the ground surface facing downwards, adding 3-4 spoons of bakelite powder, pressing a top cover downwards, and inlaying the sample according to the following parameters.

Pressure: 230-250 Bar

Heating temperature: 170-190 DEG C

Heating time: 4-5 min, cooling time: 4-5 min

The sample grinding method comprises grinding and polishing.

Grinding:

and (5) grinding and polishing the sample by using an automatic grinding and polishing machine.

The method comprises the steps of selecting 320#, 500#, 1200# abrasive paper for rough grinding and fine grinding respectively, adhering the abrasive paper on a grinding disc, wiping water marks on the grinding disc and a magnetic disc, adhering the grinding disc on the magnetic disc, and aligning and matching the grinding disc and the magnetic disc. The embedded sample is placed on a fixture, and a dry towel is used for wiping water marks on the grinding disc and the magnetic disc. And opening a water supply device and a gas supply device to carry out a grinding process, controlling the gas pressure to be 0.5-0.8MPa, and grinding each abrasive paper for 2-4 min.

Polishing:

polishing was performed using an automatic polishing machine to remove fine grinding marks after finish grinding to obtain a bright mirror surface. And after finishing grinding, polishing, and attaching a polishing disk to the magnetic disk, wherein the polishing disk and the magnetic disk are required to be aligned and matched. And (4) placing the sample of the grinding number on a clamp, pre-spraying polishing liquid for 3-5 seconds, and then automatically polishing. And after the rough polishing is finished, replacing the fine polishing disk for fine polishing, wherein the operation steps are the same as the above. And the rough polishing time is 1-3 min, the fine polishing time is 2-4 min, and after the fine polishing is finished, the sample is cleaned by clear water for later use.

Fig. 2 is an erosion degree evaluation reference map according to an exemplary embodiment of the present application.

And (4) observing the corroded sample wafers under a microscope respectively, selecting m areas with the most serious corrosion on each sample wafer, and grading each area according to the standard of the application.

The scoring criteria (tables 1 and 2) in the present application can be appropriately adjusted according to the number of samples, and the evaluation method is not changed.

The present application is further illustrated by the following specific examples.

Example 1

(1) Obtaining a measurement sample

Two round holes each having a diameter of 5mm were drilled in a sample piece having a size of 10cm × 6cm and a rolling direction of 10cm, at a distance of 1cm from the upper end and at a distance of 3cm from the both ends (the sample piece size was set based on the type of the brazing furnace used in this example). The swatch is as in figure 1.

(2) Sample wafer simulation brazing process

Two small holes of the sample wafer are penetrated into the cross beam for suspension, the sample wafer is placed into a brazing furnace for brazing according to the following parameters to simulate the brazing process, and 5 sample wafers are placed in each furnace.

Simulating brazing process parameters: heating to 490 deg.C at room temperature for 12min, heating to 490 deg.C to 570 deg.C, heating to 6min, heating to 570 deg.C to 595 deg.C, heating to 2min, and holding at 595 deg.C for 4 min.

(3) Etching treatment of sample wafer

Cutting off 2cm of the upper end and the lower end of the sample piece after the simulated brazing, reserving a 2cm part of the middle part, cutting out a small sample piece with the length of 3cm as a sample piece to be observed, inlaying the sample piece according to the section with the observation direction as the longitudinal direction (rolling direction), performing coarse grinding and fine grinding, and observing the corrosion condition under a microscope after corrosion.

(4) Specimen viewing

The 3cm long longitudinal (in the rolling direction) section was observed under a microscope at a magnification of 100, 2 areas where the erosion was most severe were searched, 6 areas were selected for 3 specimens observed, and each area was scored.

The scores are shown in the following table:

TABLE 1

ES	Description of the invention	Typical picture
			1	No significant penetration and diffusion into the core material was found to cause erosion	FIG. 2A
2	Has ablation, the deepest depth of the single ablation is less than 30 percent of the thickness of the composite foil	FIG. 2B
			3	Occurrence of 1-point penetration corrosion	FIG. 2C
4	The penetration corrosion of 2 places and more than 2 places occurs	FIG. 2D
			5	Large area through-ablation occurs	FIG. 2E

(5) Evaluation of degree of erosion

The sum of The Erosion Score (TES) of 6 regions was calculated, and the degree of Erosion was evaluated according to the Score in the following table:

TABLE 2

Example 2

The procedure was essentially the same as in example 1, except that: simulating brazing process parameters: heating to 510 deg.C at room temperature for 15min, heating to 580 deg.C at 510 deg.C for 8min, heating to 610 deg.C at 580 deg.C for 2.5min, and holding at 610 deg.C for 6 min.

Example 3

The procedure was essentially the same as in example 1, except that: simulating brazing process parameters: simulating a brazing process, heating the room temperature to 500 ℃ for 13min, heating the 500 ℃ to 577 ℃ for 7min, heating the 577 ℃ to 600 ℃ for 2min, and keeping the 600 ℃ for 5 min.

The aluminum alloy composite foil is evaluated by the method (the sample used in the test is self-made), and the results are as follows:

test example 1

The sample is a fin foil with the thickness of 0.07mm, and the method of the embodiment is adopted to evaluate the corrosion degree of the aluminum alloy composite foil, and the results are shown in the following table:

test example 2

The sample is a fin foil with the thickness of 0.07mm, and the method of the embodiment is adopted to evaluate the corrosion degree of the aluminum alloy composite foil, and the results are shown in the following table:

test example 3

The samples were fin foil 0.08mm thick, and the evaluation of the degree of corrosion of the aluminum alloy composite foil was carried out by the method described in the above examples, with the results as follows:

test example 4

The samples are fin foils with the thickness of 0.09mm, and the method of the embodiment is adopted to evaluate the corrosion degree of the aluminum alloy composite foil, and the results are shown in the following table:

test example 5

The samples are fin foils with the thickness of 0.09mm, and the method of the embodiment is adopted to evaluate the corrosion degree of the aluminum alloy composite foil, and the results are shown in the following table:

comparative example 1

A commercially available condenser was used, the thickness of the fin foil was 0.08mm, and samples were taken near the transverse center line, near the top, in the middle and at the top (see FIG. 10), and small sample pieces were cut out (see FIG. 11), and evaluated by the ablation method in accordance with the method of the present application (in FIG. 9, uncut sample pieces).

The results are given in the following table:

the method is adopted to evaluate and measure the fins of the marketed products, the measuring result is consistent with the predicted erosion resistance degree, and the method is proved to be accurate and feasible.

It should be understood that the above examples are only for clearly illustrating the present application and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of this invention may be made without departing from the spirit or scope of the invention.