阅读说明：本技术 锡铅合金及其制备工艺 (Tin-lead alloy and preparation process thereof ) 是由 柴为民 路远航 张鑫波 骆芳 沈逸周 蒋荣杰 袁林江 于 2020-12-10 设计创作，主要内容包括：本发明提供了一种锡铅合金及其制备工艺,涉及金属合金涉及技术领域,工艺包括以106℃—115℃为应用温度,以锡铅二元相图为基础,选取重量份为2-5份的锡、30-45份的铅,40-60份的铋；将上述原料放入到熔炼炉内,调整熔炼温度到700-800℃进行炼制,并进行搅拌熔化；将熔炼温度调整至300-350℃,搅拌至全部熔化后去除表层扒渣,并让其静置后得到金属热熔体；将热熔料过滤后,置入铸型中,冷却后得到金属锭；将金属锭加工成标准试样尺寸；将合金阀芯样品装入氢气阀进行熔点和压力测试。本发明锡铅合金具有较高的抗压强度,在且锡铅合金熔点的温度范围较小,锡铅合金阀芯能够在大于77MPa的压力下长期工作,在瞬间压力达到87.5MPa时不破碎变形的特性。(The invention provides a tin-lead alloy and a preparation process thereof, which relate to the technical field of metal alloys and comprise the steps of selecting 2-5 parts by weight of tin, 30-45 parts by weight of lead and 40-60 parts by weight of bismuth on the basis of a tin-lead binary phase diagram by taking 106-115 ℃ as an application temperature; putting the raw materials into a smelting furnace, adjusting the smelting temperature to 700-; adjusting the smelting temperature to 300-350 ℃, stirring until the molten metal is completely melted, removing surface skimming, and standing to obtain a metal hot melt; filtering the hot melt, putting the hot melt into a casting mold, and cooling to obtain a metal ingot; processing the metal ingot into a standard sample size; and (3) loading the alloy valve core sample into a hydrogen valve for melting point and pressure tests. The tin-lead alloy has the characteristics of higher compressive strength, smaller temperature range of the melting point of the tin-lead alloy, capability of working for a long time under the pressure of more than 77MPa, and no crushing deformation when the instantaneous pressure reaches 87.5 MPa.)

1. The tin-lead alloy is characterized by comprising the following raw materials in parts by weight: 2-5 parts of tin, 30-45 parts of lead and 40-60 parts of bismuth.

2. A tin-lead alloy and a preparation process thereof are characterized by comprising the following steps:

(1) selecting 2-5 parts by weight of tin based on a tin-lead binary phase diagram at an application temperature of 106-115 ℃;

(2) selecting 30-45 parts by weight of lead and 40-60 parts by weight of bismuth from low-melting-point alloy according to the required pressure of more than 77 MPa;

(3) putting the metal raw materials in parts by weight into a smelting furnace, adjusting the smelting temperature to 700-800 ℃ for smelting, and stirring and melting;

(4) adjusting the smelting temperature to 300-350 ℃, stirring until the alloy is completely molten, removing surface skimming, and standing to obtain an alloy hot melt;

(5) filtering the alloy hot melt, putting the alloy hot melt into a casting mold, and cooling to obtain an alloy ingot;

(6) processing an alloy ingot into a standard sample size to obtain an alloy valve core sample;

(7) and (4) carrying out melting point and pressure tests on the alloy sample valve core sample, and processing the finished product to be filled into a hydrogen cylinder for carrying out melting point and pressure safety tests.

3. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: the purity of tin is more than or equal to 99.8 percent, the purity of lead is more than or equal to 99.8 percent, the purity of bismuth is more than or equal to 99.8 percent, and the purity of antimony and indium is more than or equal to 99.8 percent.

4. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: the lead material and the tin material are granular, and the size of the lead material and the tin material is 20-40 mm.

5. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: in the step (4), the stirring and melting time is 30-50 minutes.

6. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: and (4) cooling the alloy hot melt to 300-400 ℃ along with the furnace, wherein the cooling along with the furnace is carried out under a vacuum condition, and the vacuum degree is 0.1-1 Pa.

7. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: and (4) stirring in the step (4) adopts electromagnetic stirring, wherein the electromagnetic stirring is started every 9-12min in the furnace cooling process, and the stirring time is 3-5 min each time.

8. The tin-lead alloy and the preparation process thereof as claimed in claim 2, wherein: and (3) loading the alloy sample valve core sample into a hydrogen valve to carry out pressure and melting point tests.

Technical Field

The invention relates to a tin-lead alloy and a preparation process thereof, belonging to the technical field of metal alloy design.

Background

Compared with traditional fossil energy such as petroleum and coal, the hydrogen energy has the advantages of cleanness, environmental protection, various sources, large-scale storage and transportation and the like, and plays an important role in energy structure. As an energy storage component of a hydrogen fuel cell automobile, a convenient and efficient hydrogen storage mode is one of key technologies for realizing large-scale commercialization of the hydrogen fuel cell automobile. High-pressure gaseous hydrogen storage and liquid hydrogen storage are two main hydrogen storage modes, and are popularized and applied. The high-pressure gaseous hydrogen storage has the advantages of simple container structure, less energy consumption for preparing compressed hydrogen, high filling speed and the like, and is a mode which is mature in technical development and most widely applied in the field of domestic hydrogen fuel cell automobiles at present. Although the vehicle-mounted high-pressure gaseous hydrogen storage technology has been demonstrated and applied, a plurality of technical bottlenecks still exist in a high-performance vehicle-mounted high-pressure hydrogen storage system in China.

The cylinder mouth valve is one of key components of the whole vehicle-mounted high-pressure hydrogen storage system, plays a key role in overpressure protection of a high-pressure gas cylinder, and the 77MPa hydrogen storage pressure puts higher requirements on the performance of the cylinder mouth valve of the gas cylinder. The bottle mouth valve needs to be ensured to be in service for a long time at normal temperature and under 77MPa high pressure; when the temperature reaches 106-115 ℃, the alloy is instantly melted, and the pressure is reduced by exhausting gas to avoid hydrogen explosion; meanwhile, when the instantaneous pressure reaches 87.5MPa, the designed alloy is not cracked and deformed.

Therefore, the research and development of the low-melting-point high-pressure-resistant tin-lead alloy material which has simple process, easy operation and low manufacturing cost and can meet the requirements as the valve core of the bottle mouth valve of the high-pressure gas bottle is urgent.

The present application was made based on this.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a tin-lead alloy and a preparation process thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the tin-lead alloy comprises the following raw materials in parts by weight: 2-5 parts of tin, 30-45 parts of lead and 40-60 parts of bismuth.

A tin-lead alloy and a preparation process thereof comprise the following steps:

(1) selecting 2-5 parts by weight of tin based on a tin-lead binary phase diagram at an application temperature of 106-115 ℃;

(2) selecting 30-45 parts by weight of lead and 40-60 parts by weight of bismuth from low-melting-point alloy according to the required pressure of more than 77 MPa;

(3) putting the metal raw materials in parts by weight into a smelting furnace, adjusting the smelting temperature to 700-800 ℃ for smelting, and stirring and melting;

(4) adjusting the smelting temperature to 300-350 ℃, stirring until the alloy is completely molten, removing surface skimming, and standing to obtain an alloy hot melt;

(5) filtering the alloy hot melt, putting the alloy hot melt into a casting mold, and cooling to obtain an alloy ingot;

(6) processing an alloy ingot into a standard sample size to obtain an alloy valve core sample;

(7) and (4) carrying out melting point and pressure tests on the alloy sample valve core sample, and processing the finished product to be filled into a hydrogen cylinder for carrying out melting point and pressure safety tests.

Furthermore, the purity of tin is more than or equal to 99.8 percent, the purity of lead is more than or equal to 99.8 percent, the purity of bismuth is more than or equal to 99.8 percent, and the purity of antimony and indium is more than or equal to 99.8 percent.

Further, the lead and tin metals are granular, have a size of 20-40mm, and may have a size of 22mm, 25mm, 28mm, 30mm, 32mm, 35mm, 38mm, or a range of any two of the above values. Compared with powdery raw materials, the blocky raw materials adopted by the invention can avoid powder flying dust and pollution in the burdening process; the method can also avoid the problems of serious oxygen absorption and water absorption caused by large specific surface area of the powder raw material, and the problems of high oxygen content, more oxidizing impurities generated by later-stage smelting, raw material loss and uneven components, namely, the method has the advantages of low pollution of the bulk raw material, low oxygen content, less oxidizing impurities after smelting, low raw material loss and good component uniformity. In addition, the alloy obtained by the method of mixing raw materials and smelting firstly has better component uniformity, especially when preparing products with larger weight and size. The raw materials of the invention are preferably 20-40mm, which is convenient for processing on one hand and simultaneously melting the two raw materials on the other hand, thereby avoiding uneven components.

Further, in the step (4), the stirring and melting time is 30-50 minutes, so that the stirring is sufficient and uniform.

Further, in the step (4), the alloy hot melt is cooled to 300-400 ℃ along with the furnace, and the cooling along with the furnace is carried out under the vacuum condition, wherein the vacuum degree is 0.1-1 Pa.

Further, electromagnetic stirring is adopted for stirring in the step (4), and is started every 9-12min in the furnace cooling process, wherein the stirring time is 3-5 min each time. The components can be further homogenized by electromagnetic stirring; the electromagnetic stirring is started at intervals to keep the smelting temperature within a certain range. The electromagnetic stirring is carried out in the cooling process, so that the composition segregation in the cooling process can be avoided, and the composition is more uniform.

Further, the alloy sample valve core sample is arranged in a hydrogen valve for pressure and melting point tests.

The invention can realize the following technical effects:

(1) the low-melting-point high-pressure-resistant tin-lead alloy material disclosed by the invention is simple in process, low in manufacturing cost, easy to operate and suitable for large-scale popularization and use, and the whole process can be carried out in an atmospheric environment;

(2) the low melting point tin-lead alloy material has the characteristic of instantaneous melting at 106-115 ℃;

(3) the tin-lead alloy material designed by the invention has high compressive strength, the temperature range of the melting point of the tin-lead alloy is small, the tin-lead alloy material can meet the application requirement in a hydrogen cylinder mouth valve, and the tin-lead alloy valve core can work for a long time under the pressure of more than 77MPa and does not break and deform when the instantaneous pressure reaches 87.5 MPa. The bottle mouth valve can not leak in work or under instantaneous high pressure, and once the hydrogen temperature is too high, the tin-lead alloy valve core can be rapidly melted to release pressure and cool. The safety of the protection equipment plays a role in protection.

Drawings

FIG. 1 is a dimensional diagram of a standard sample of an alloy valve core according to the invention;

FIG. 2 is a metallographic diagram of a valve element obtained by a process for preparing a tin-lead alloy material according to example 1 of the present invention;

FIG. 3 is a metallographic diagram of a valve element obtained by a process for preparing a tin-lead alloy material according to example 2 of the present invention;

FIG. 4 is a metallographic diagram of a valve element obtained by a process for preparing a tin-lead alloy material according to embodiment 3 of the present invention;

fig. 5 is a valve element compressive stress-strain diagram obtained by the process for preparing the tin-lead alloy material of embodiment 1 of the invention;

fig. 6 is a valve element compressive stress-strain diagram obtained by the process for preparing the tin-lead alloy material of embodiment 2 of the present invention;

fig. 7 is a compressive stress-strain diagram of the valve element obtained by the process for preparing the tin-lead alloy material in embodiment 3 of the invention.

Detailed Description

In order to make the technical means of the present invention and the technical effects achieved thereby clearer and more complete, the following embodiments are provided as detailed descriptions:

example 1

The tin-lead alloy of the embodiment comprises the following raw materials in parts by weight: 2 parts of tin, 30 parts of lead and 40 parts of bismuth.

The tin-lead alloy and the preparation process thereof comprise the following steps:

(1) selecting 2 parts by weight of tin based on a tin-lead binary phase diagram at an application temperature of 106 ℃; the purity of tin is more than or equal to 99.8 percent, the purity of lead is more than or equal to 99.8 percent, the purity of bismuth is more than or equal to 99.8 percent, and the purity of antimony and indium is more than or equal to 99.8 percent. The lead and tin metals were granular and had a size of 20 mm.

(2) Selecting 30 parts by weight of lead and 40 parts by weight of bismuth from the low-melting-point alloy according to the required pressure of more than 77 MPa;

(3) putting the metal raw materials in parts by weight into a smelting furnace, adjusting the smelting temperature to 700 ℃ for smelting, and stirring and melting;

(4) adjusting the smelting temperature to 300 ℃, stirring until the alloy is completely molten, removing surface slag, and standing to obtain an alloy hot melt; the stirring melting time was 30 minutes and the standing time was 25 minutes. The alloy hot melt is cooled to 300 ℃ along with the furnace, and the cooling along with the furnace is carried out under the vacuum condition, and the vacuum degree is 0.1 Pa. Electromagnetic stirring is adopted for stirring, and in the process of cooling along with the furnace, the electromagnetic stirring is started every 9min, and the stirring time is 3min each time.

(5) Filtering the alloy hot melt, putting the alloy hot melt into a casting mold, and cooling to obtain an alloy ingot;

(6) processing an alloy ingot into a standard sample size (as shown in figure 1) to obtain an alloy valve core sample;

(7) and (4) carrying out melting point and pressure tests on the alloy sample valve core sample, and processing the finished product to be filled into a hydrogen cylinder for carrying out melting point and pressure safety tests. The deformation curve of the sample under pressure is shown in fig. 5.

Example 2

The tin-lead alloy of the embodiment comprises the following raw materials in parts by weight: 3 parts of tin, 40 parts of lead and 50 parts of bismuth.

The tin-lead alloy and the preparation process thereof comprise the following steps:

(1) selecting 3 parts by weight of tin based on a tin-lead binary phase diagram at the application temperature of 110 ℃; the purity of tin is more than or equal to 99.8 percent, the purity of lead is more than or equal to 99.8 percent, the purity of bismuth is more than or equal to 99.8 percent, and the purity of antimony and indium is more than or equal to 99.8 percent. The lead and tin metals were granular and 28mm in size.

(2) Selecting 40 parts by weight of lead and 50 parts by weight of bismuth from the low-melting-point alloy according to the required pressure of more than 77 MPa;

(3) putting the metal raw materials in parts by weight into a smelting furnace, adjusting the smelting temperature to 750 ℃ for smelting, and stirring and melting;

(4) adjusting the melting temperature to 330 ℃, stirring until the melting temperature is completely melted, removing the surface layer slag, and standing to obtain an alloy hot melt; the stirring melting time was 40 minutes and the standing time was 28 minutes. The alloy hot melt is cooled to 350 ℃ along with the furnace, and the cooling along with the furnace is carried out under the vacuum condition, and the vacuum degree is 0.5 Pa. The stirring adopts electromagnetic stirring, and the electromagnetic stirring is started every 10min in the furnace cooling process, and the stirring time is 4min each time.

(5) Filtering the alloy hot melt, putting the alloy hot melt into a casting mold, and cooling to obtain an alloy ingot;

(6) processing an alloy ingot into a standard sample size (as shown in figure 1) to obtain an alloy valve core sample;

(7) and (4) carrying out melting point and pressure tests on the alloy sample valve core sample, and processing the finished product to be filled into a hydrogen cylinder for carrying out melting point and pressure safety tests. The deformation curve of the sample under pressure is shown in fig. 6.

Example 3

The tin-lead alloy of the embodiment comprises the following raw materials in parts by weight: 5 parts of tin, 45 parts of lead and 60 parts of bismuth.

The tin-lead alloy and the preparation process thereof comprise the following steps:

(1) selecting 5 parts by weight of tin based on a tin-lead binary phase diagram at an application temperature of 115 ℃; the purity of tin is more than or equal to 99.8 percent, the purity of lead is more than or equal to 99.8 percent, the purity of bismuth is more than or equal to 99.8 percent, and the purity of antimony and indium is more than or equal to 99.8 percent. The lead and tin metals were granular and 40mm in size.

(2) Selecting 45 parts by weight of lead and 60 parts by weight of bismuth from the low-melting-point alloy according to the required pressure of more than 77 MPa;

(3) putting the metal raw materials in parts by weight into a smelting furnace, adjusting the smelting temperature to 800 ℃ for smelting, and stirring and melting;

(4) adjusting the smelting temperature to 350 ℃, stirring until the alloy is completely molten, removing surface slag, and standing to obtain an alloy hot melt; the stirring melting time was 50 minutes, and the standing time was 30 minutes. The alloy hot melt is cooled to 400 ℃ along with the furnace, and the cooling along with the furnace is carried out under the vacuum condition, and the vacuum degree is 1 Pa. Electromagnetic stirring is adopted for stirring, and in the process of cooling along with the furnace, the electromagnetic stirring is started every 12min, and the stirring time is 5min each time.

(5) Filtering the alloy hot melt, putting the alloy hot melt into a casting mold, and cooling to obtain an alloy ingot;

(6) processing an alloy ingot into a standard sample size (as shown in figure 1) to obtain an alloy valve core sample;

(7) and (4) carrying out melting point and pressure tests on the alloy sample valve core sample, and processing the finished product to be filled into a hydrogen cylinder for carrying out melting point and pressure safety tests. The deformation curve of the sample under pressure is shown in fig. 7.

The gold phase diagrams of the tin-lead alloy valve cores prepared in the above embodiments 1 to 3 of the present invention are respectively shown in fig. 2 to 4, and it can be seen from fig. 2 to 4 that the solidification structure is composed of a eutectic structure and is uniformly distributed.

The above description is provided for the purpose of further elaboration of the technical solutions provided in connection with the preferred embodiments of the present invention, and it should not be understood that the embodiments of the present invention are limited to the above description, and it should be understood that various simple deductions or substitutions can be made by those skilled in the art without departing from the spirit of the present invention, and all such alternatives are included in the scope of the present invention.