CN102642099A - A kind of Sn-Zn based lead-free solder alloy for aluminum-copper soldering and preparation method thereof - Google Patents

Abstract

An Sn-Zn based lead-free solder alloy for aluminum copper soldering and a preparation method thereof belong to the technical field of new materials. The solder alloy comprises the following components in percentage by weight: zn is 7-8.5%; 0.2 to 0.49 percent of Al; ag is 0.55-0.7%; p is 0-0.1%; ni is 0-1%; RE is 0-0.5%, and Sn is the rest. The preparation method comprises the following steps: smelting a Zn-Al intermediate alloy, smelting the alloy according to the proportion of Zn to 6Al at the temperature of 450 ℃ in a protective atmosphere, firstly melting Zn, then adding Al, stirring uniformly and then cooling. (2) Smelting a brazing alloy, sealing the pure metal and the intermediate alloy in a quartz tube according to the alloy proportion, heating the quartz tube after vacuumizing, stirring uniformly after the alloy is completely melted, keeping the temperature for 3 hours, and taking out the alloy by water cooling. Compared with the existing Sn-based lead-free solder alloy, the Sn-based lead-free solder alloy has better wettability on copper and aluminum, thereby having good welding performance; the welding joint has excellent mechanical property, and is more suitable for aluminum-copper soldering than the prior Sn-Ag-Cu and Sn-9Zn solder.

Description

A kind of Sn-Zn based lead-free solder alloy for aluminum-copper soldering and preparation method thereof

technical field

The invention relates to a Sn-Zn-based lead-free solder alloy for aluminum-copper soldering and a preparation method thereof, belonging to the technical field of new materials.

Background technique

Copper has good electrical conductivity, thermal conductivity, plastic processing performance, brazing and corrosion resistance; therefore, it has been widely used in the fields of electricity transmission, heat exchange and daily necessities, especially air conditioners and refrigerators in the refrigeration industry Copper tubes are used as the material of the refrigeration piping system. However, with the shortage of copper resources, the price of copper has remained high in recent years, and is still rising continuously. This prompted people to start looking for alternatives to copper to reduce costs. Because the price of aluminum is relatively low and has excellent electrical conductivity, thermal conductivity, corrosion resistance and easy processing performance, it can fully meet the performance requirements in many occasions where copper was originally used, and will greatly reduce the cost of its products. The refrigeration industry uses a relatively large amount of copper. The rise in copper prices and the depletion of copper resources have affected the competitiveness of the entire industry. Substituting aluminum for copper can not only greatly reduce the cost of refrigeration products, but also not reduce the performance of refrigerators. Therefore, in recent years, domestic It has become a trend that the evaporator and other components in the piping system of the external refrigerator are made of aluminum tubes.

However, at present, it is technically difficult to obtain low-cost, high-performance, and convenient aluminum-copper joints. This is because: 1. There is a large difference in melting point: the melting point of pure aluminum is 660°C, and that of pure copper is 1085°C. Since the melting points of aluminum and copper are very different (425°C), it is difficult to melt at the same time. 2. Easy to oxidize: A layer of dense Al ₂ O ₃ oxide film is easy to form on the surface of aluminum in the air, which hinders the combination of aluminum and copper during welding and brings difficulties to welding. 3. Cracks are easy to occur: eutectic Al-Al ₂ Cu is formed during welding, which makes the weld brittle. At the same time, the expansion coefficient of aluminum is about 0.5 times that of copper, which easily leads to cracks in the weld. 4. Easy to corrode: The electrode potential difference between aluminum and copper is 1.997V, which can easily lead to electrochemical corrosion (the standard electrode potential of aluminum is 1.66V, and the standard electrode potential of copper is 0.337V). 5. Easy to form pores: Liquid aluminum and copper can dissolve and absorb a large amount of gas (such as hydrogen) at high temperature. When cooling, the solubility of the gas in the alloy solution decreases rapidly and cannot overflow, and forms pores in the weld. Therefore, in order to replace copper with aluminum, the first thing to solve is the problem of aluminum-copper connection.

The current welding methods between copper and aluminum mainly include fusion welding, pressure welding and brazing: the melting points of aluminum and copper are very different, and often the aluminum is melted while the copper is still in a solid state, which is easy to form unfused and inclusions, making welding difficult larger. Aluminum is strongly oxidized during the welding process, and the oxide film contains a certain amount of adsorbed water and crystal water, which is easy to produce pores. Aluminum has a large coefficient of thermal expansion, but a small coefficient of elasticity, resulting in large deformation after welding. Pressure welding is currently the main method used for aluminum-copper connections. However, it is limited by the structural form of parts, so it cannot be applied in many occasions, and its process is complicated and its production cost is high. The brazing method has low cost, good adaptability, and can be produced on-line. It is an aluminum-copper connection technology with good development prospects; brazing is divided into hard brazing and soft brazing according to the melting point of the brazing material. The American Welding Society (AWS) stipulates that the temperature of the solder liquidus above 450°C is called brazing, and that below 450°C is called soft soldering. The current brazing for connecting aluminum tubes and copper tubes mainly chooses aluminum-silicon based solders, for example: Al-12.6wt% Si eutectic (eutectic temperature 577°C) or solders with the addition of the third component. Usually vacuum heating or automatic flame heating is used. Brazing flame welding also has its own shortcomings: (1) The melting point of Al is 660°C, and the temperature control is not good. The aluminum tube will partially melt and cause the tube wall to become thinner. In addition, the high temperature will aggravate the ablation at the joint and affect the joint. performance. In particular, it is difficult to restore the bright layer on the surface of the copper tube after bright treatment, which seriously affects the subsequent brazing quality; for aluminum tubes, the surface ablation is more serious, and the tensile test of the joint shows that this area is weak link, the fracture occurs in the heat-affected zone of the aluminum tube near the joint. (2) The brazing temperature is generally around 500°C. Al and Cu atoms diffuse relatively quickly, and it is easy to form a fusible and brittle Al-CuAl ₂ eutectic compound, resulting in a decrease in joint strength. (3) Generally, strong corrosive flux is used to remove the oxide film of aluminum. The residue of flux is highly corrosive, corrodes the pipe wall and is difficult to clean. (4) The brazed joints cannot be easily disassembled during the production and commissioning of the machine, and the technical requirements for flame welding in the rework of the butt joints and the secondary welding process are relatively high, and it is difficult to meet high-quality brazing requirements. The soft soldering method has strong adaptability and good flexibility. Different solders can be selected according to specific conditions to obtain brazed joints with different strengths and different working temperatures. It is suitable for various occasions and meets the environmental protection requirements of aluminum and copper in the new situation. Requirements for lead-free solders for soldering. Therefore, the development of lead-free solder suitable for aluminum-copper dissimilar metal soldering, which can form a good joint is the key to realize the replacement of copper by aluminum.

Sn-Pb based solder is a widely used low-temperature brazing filler metal, and the most widely used one is 63Sn-37Pb eutectic solder with a melting point of 183°C. The Sn-Pb solder with this composition has the lowest melting point, and can be directly transformed from a liquid phase to a solid phase without going through a semi-molten state, and has excellent wettability, so this solder is most commonly used in the micro-interconnection of electronic components. However, the heavy metal lead is a toxic element. Lead enters nature along with discarded electronic products, dissolves into acid rainwater, penetrates into soil, and finally dissolves into groundwater. Drinking lead-containing groundwater will damage the health of the body. In order to prevent lead from polluting the natural environment, countries have successively imposed strict restrictions on the application of lead in industry. The European Union has banned the use of leaded solder in the electronics industry in 2006. The Japanese Environmental Agency advocates gradually reducing the amount of lead used in industry. The United States passed the Lead Exposure Act in 1991, imposing high disposal fees on discarded electronic products. . From the analysis of the trend of legislation in various countries, it has become an inevitable choice to replace lead-containing materials with lead-free materials.

The currently commonly used Sn-9Zn solder alloy has a melting point of 198°C, which is close to the eutectic Sn-Pb, and has good economical and mechanical properties. The Zn in the Sn-9Zn solder has a good affinity with the copper substrate and the aluminum substrate. It is found that the Sn-9Zn solder reacts with the copper substrate to form a Cu-Zn intermetallic compound; the mutual solubility of Zn and Al is relatively large. A solid solution is formed in a wide range, and the Sn-9Zn solder reacts with the aluminum plate to form an Al-Zn-Sn solid solution zone at the aluminum interface. At the same time, Zn will also form thorny solid solution whiskers on the aluminum substrate to insert into the solder to embed and bond. However, Zn element is a metal with strong activity. A large amount of Zn is easy to oxidize the surface of the solder in the molten state, resulting in a large surface tension of the alloy, which seriously affects the wettability and oxidation resistance of the solder. Sn-Zn solder The preservation of the brazing system is poor, and long-term storage will cause many problems such as low bonding strength. At the same time, due to the extremely poor corrosion resistance of the single Zn phase, the solder joints are prone to corrosion and failure in a humid environment. These problems have affected to a certain extent. applications of the alloy.

Contents of the invention

The purpose of the present invention is to provide a kind of all having good wettability on copper plate and aluminum plate, can effectively A Sn-Zn-based near-eutectic lead-free solder alloy suitable for soldering aluminum-copper dissimilar metals that connects these two metals and forms a brazing joint with higher strength.

The technical solution adopted by the present invention is: a kind of Sn-Zn base lead-free solder alloy for aluminum-copper soldering, described Sn-Zn base lead-free solder alloy comprises the following components by weight percentage: Zn is 7-8.5%, Al is 0.2-0.49%, Ag is 0.55-0.7%, P is 0-0.1%, Ni is 0-1%, RE is 0-0.5%, and the rest is Sn.

A kind of preparation method of described Sn-Zn base lead-free solder alloy for aluminum-copper soldering, its preparation process comprises the following steps:

(1) Melting Zn-Al master alloy

According to the percentage by weight, Al is 6%, and Zn is the balance of Zn-Al master alloy. It is required to weigh the metal Zn with a purity of 99.99% and the metal Al with a purity of 99.99%. Under the protective atmosphere of nitrogen or argon, heat up Melt metal Zn at 450-500°C first, then add metal Al, stir well, keep warm for 10-15min, then cool down and take out;

(2) Melting Sn-Zn based near-eutectic lead-free solder alloy

① The preparation of Sn-Zn-based near-eutectic lead-free solder alloy is to use metal Sn with a purity of 99.99%, Zn-6Al master alloy, metal Ag with a purity of 99.99%, metal Ni with a purity of 99.99%, and a P content of The commercially available Sn-P alloy with 15% by weight is smelted with RE, and the components of the solder alloy are proportioned according to the mass ratio, a total of 200 grams, and placed in the high temperature resistant tube;

② Use a hydrogen flame to melt and seal one end of the high-temperature resistant tube, and melt the other end into a thin mouth and vacuumize it with a vacuum pump. After the air in the pipe is exhausted, melt and seal the thin mouth;

③Put the high-temperature resistant tube in a resistance furnace, heat it to 400°C for melting, and keep it warm for 2-3 hours after all the components are melted. After being in a uniform liquid state, cool down to room temperature and take out the solder.

The high temperature resistant tube adopts quartz tube or ceramic tube.

Compared with the traditional Sn-9Zn solder alloy, after adding Al to the Sn-Zn solder, due to the large solid solubility between Zn-Al, Al exists in the form of solid solution in Zn in the solder. Due to the low density of the Al element, it will adhere to the surface to form a thin oxide layer when the solder melts, thereby preventing the oxidation of Zn in the solder, thereby improving the oxidation resistance and wettability of the Sn-Zn-based solder sex. At the same time, the addition of an appropriate amount of Al can increase the strength of the Sn-Zn-based solder and improve the strength of the brazed joint to a certain extent. However, too high Al content (higher than 1%) will form an excessively thick oxide layer on the surface of the solder, which will reduce the wettability.

On the other hand, although the Al element will have a solid solution strengthening effect on the solder, the hardness of the solder will increase, while the plasticity will decrease, and cracking will easily occur during the rolling process. Further studies have shown that the plasticity of the solder is improved after adding Ag to the solder, and there is no cracking phenomenon in the plastic processing process, which has excellent plastic workability; moreover, the addition of Ag can improve the corrosion resistance of the solder . In order to study the influence of Ag element on the corrosion resistance of solder, the inventors carried out electrochemical corrosion tests on two solders of Sn-8.4Zn-0.73Ag and Sn-8.4Zn-0.44Al, and the corrosion solution was 3.5% NaCl solution . The self-corrosion potentials of the two solders were measured in experiments as -0.96V and -1.07V respectively; from the experimental results, it can be seen that under the same Zn content, the corrosion resistance of the solder after adding Ag is better than adding Al. . Both theory and experiment show that adding Ag element to Sn-Zn solder, Ag element will form intermetallic compound AgZn ₃ phase with Zn element, reduce the oxidation of Zn on the surface of solder, improve the wettability of solder, and then improve improve the welding performance of the solder; at the same time, the presence of a small amount of AgZn ₃ particles can play a role in dispersion strengthening of the brazed joint and improve the mechanical properties of the joint; moreover, the addition of Ag can improve the corrosion resistance of the solder; however, at the same time , the inventor also found that when 3% Ag is added to Sn-9Zn, a large number of large AgZn ₃ phases will be formed in the structure of the brazed joint, which will cause a decrease in the mechanical properties of the joint.

Ni element can form Ni ₅ Zn ₂₁ phase with Zn in the solder, which can reduce the content of Zn in the solder and improve the corrosion resistance of the solder, but adding too much Ni to the solder will increase the melting point of the alloy and increase The melting range is not conducive to welding. At the same time, it is found that when the content of Ni element exceeds 1%, the Ni ₅ Zn ₂₁ phase in the solder grows into a large block, and Ni ₃ Sn ₄ phase precipitates from it, and the strength of the joint decreases accordingly, so the Ni element The content should not exceed 1%.

P element can inhibit the surface oxidation of the alloy melt, which replaces Zn oxidation on the surface of the alloy melt to form a barrier layer, and the oxide of P is not static, but is continuously generated and volatilized, so it will not remain on the surface of the melt Excessive oxidation products can improve the wettability of the alloy to the substrate. At the same time, the P element has a lower density than the Al element, which can also protect the excessive burning of the Al element in the molten state and inhibit the formation of an excessively thick oxide film.

The addition of trace rare earth elements has little effect on the melting point of the solder alloy, but the addition of rare earth can significantly inhibit the formation of coarse Sn grains, and refine the Zn-rich phase, making it change from a few microns to less than 1 micron, improving the joint The strength of the joint can also improve the creep resistance of the joint. At the same time, the rare earth element has a certain adsorption effect on oxygen, which can improve the oxidation resistance of the solder, and has a positive effect on the use and promotion of the solder.

Because Zn element and Al element are easy to be burned, the alloy composition is inaccurate during smelting, so the present invention first smelts the Zn-Al master alloy when smelting the brazing filler metal, determines the Zn-Al composition percentage through chemical analysis, and then uses the master alloy as the ingredient To prepare the brazing alloy, in order to prevent the quality loss caused by Zn evaporation during the smelting process, the invention smelts the alloy in a vacuum-treated high-temperature-resistant tube to obtain a brazing alloy with precise composition and uniform structure.

The effects and benefits of the present invention are: 1. due to the addition of an appropriate amount of Al elements and Ag elements, it has good wettability on copper plates and aluminum plates, and the addition of Ni elements makes the solder have good corrosion resistance; 2. The addition of P and RE purifies the alloy structure, thereby having better welding properties, making its welded joints have excellent mechanical properties; 3. The Sn-Zn-Ag-Al-Ni-P-RE used in the present invention The members of the group are all non-toxic elements, which meet the requirements of the electronic packaging field for lead-free solder; 4. The preparation method used in the present invention can obtain a solder alloy with precise composition and uniform structure.

Description of drawings

Fig. 1 is the brazing reflow curve of the solder described in the embodiment.

Detailed ways

The specific implementation manner of the present invention will be described in detail below in conjunction with the technical solutions.

Example 1: Each component is calculated by weight percentage: Zn 8%, Al 0.2%, Ag 0.6%, and the balance is Sn.

The alloy preparation method is as follows:

(1) Melting Zn-Al master alloy

According to the weight percentage of Al 6%, the Zn-Al master alloy with Zn as the balance requires weighing bulk pure metal Zn (purity 99.99%) and Al (purity 99.99%). Under protective atmosphere, heat up to 450-500°C to first melt metal Zn, then add metal Al, stir well, keep warm for 10-15min, cool down and take out.

(2) Melting Sn-Zn based near-eutectic lead-free solder alloy

① The preparation of Sn-Zn-based near-eutectic lead-free solder alloy is to use pure Sn (purity 99.99%), Zn-6Al master alloy, pure Ag (purity 99.99%), pure Ni (purity 99.99%), commercially available Sn -P alloy (containing P 15%) and RE smelting, proportioning the components of the solder alloy according to the weight ratio, a total of about 200 grams, and placing them in the quartz tube.

② Use a hydrogen flame to melt and seal one end of the quartz tube, and melt the other end into a thin mouth and use a vacuum pump to vacuumize. After the air in the quartz tube is exhausted, the thin mouth is melted and sealed.

③Put the quartz tube in a resistance furnace and heat it to 400°C for melting. After all the components are melted, keep it warm for 2-3 hours. During this period, turn the quartz tube over and stir once every half hour to homogenize the alloy. After the alloy is in a uniform liquid state, the temperature of the quartz tube is cooled to room temperature, and the solder is taken out.

The DSC test, the wettability test of the solder on the copper and aluminum substrates and the tensile property test of the brazed joint were carried out on the solder alloys in the above embodiments. The wettability test conditions are as follows: the solder is made into a solder ball with a diameter of 1.5 mm, the solder ball is placed on a copper plate and an aluminum plate coated with 12 mg of commercially available flux, and it is put into a reflow soldering machine Medium heating, the reflow curve is shown in Figure 1, and the spread area of the solder alloy after reflow soldering is measured using graphic software. The brazed joints were also welded using the same reflow profile for shear tensile testing.

The solidus of the lead-free solder obtained by the above ratio is at 200.67°C, and the liquidus is at 204.70°C. With the commercially available flux, the spreading area on the TP2 copper plate is 6.54cm ² , and the spreading area on the 3003 aluminum plate is 23.61 cm ² , the shear strength of the obtained Cu/Al brazing joint is 32.22MPa, and the self-corrosion potential of the solder is -0.956V.

We take Sn-9Zn as a comparative example, its spreading area on TP2 copper plate is 6.26cm ² , and its spreading area on 3003 aluminum plate is 22.99cm ² , the shear strength of the obtained Cu/Al brazing joint is 32.08MPa, The self-corrosion potential of the solder is -0.886V.

Embodiment 2: Each component is calculated by weight percentage: Zn 7.4%, Al 0.3%, Ag 0.7%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 197.32°C, and the liquidus is at 206.59°C. With the commercially available flux, the spreading area on the TP2 copper plate is 6.43m ² , and the spreading area on the 3003 aluminum plate is 22.60 cm ² , the shear strength of the obtained Cu/Al brazing joint is 33.81MPa, and the self-corrosion potential of the solder is -0.937V.

Embodiment 3: Each component is calculated by weight percentage: Zn 7.5%, Al 0.25%, Ag 0.6%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 197.45°C, and the liquidus is at 205.57°C. With the commercially available flux, the spreading area on the TP2 copper plate is 6.96m ² , and the spreading area on the 3003 aluminum plate is 24.61 cm ² , the shear strength of the obtained Cu/Al brazing joint is 33.84MPa, and the self-corrosion potential of the solder is -0.962V.

Embodiment 4: Each component is calculated by weight percentage: Zn 7%, Al 0.44%, Ag 0.6%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 197.93°C, and the liquidus is at 206.04°C. With the commercially available flux, the spreading area on the TP2 copper plate is 6.57m ² , and the spreading area on the 3003 aluminum plate is 28.34 cm ² , the shear strength of the obtained Cu/Al brazing joint is 32.65MPa, and the self-corrosion potential of the solder is -0.972V.

Embodiment 5: Each component is calculated by weight percentage: Zn 7.5%, Al 0.25%, Ag 0.6%, Ni 0.1%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is at 200.43°C, and the liquidus is at 208.12°C. With the commercially available flux, the spreading area on the TP2 copper plate is 6.32m ² , and the spreading area on the 3003 aluminum plate is 27.56 cm ² , the shear strength of the obtained Cu/Al brazing joint is 31.21MPa, and the self-corrosion potential of the solder is -0.743V.

Embodiment 6: Each component is calculated by weight percentage: Zn 7%, Al 0.44%, Ag 0.6%, P 0.01%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 198.93°C, and the liquidus is at 207.32°C. With the commercially available flux, the spreading area on the TP2 copper plate is 8.08m ² , and the spreading area on the 3003 aluminum plate is 37.11 cm ² , the shear strength of the obtained Cu/Al brazing joint is 37.42MPa, and the self-corrosion potential of the solder is -0.987V.

Example 7: Each component is calculated by weight percentage: Zn 7%, Al 0.44%, Ag 0.6%, P 0.01%, RE 0.01%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is at 199.24°C, and the liquidus is at 209.35°C. With commercial flux, the spreading area on the TP2 copper plate is 8.21m ² , and the spreading area on the 3003 aluminum plate is 35.11 cm ² , the shear strength of the obtained Cu/Al brazing joint is 39.42MPa, and the self-corrosion potential of the solder is -0.947V.

Example 9: The components by weight percentage are: Zn 8.5%, Al 0.35%, Ag 0.7%, P 0.1%, Ni 0.1%, RE 0.01%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 199.75°C, and the liquidus is at 207.31°C. With the commercially available flux, the spreading area on the TP2 copper plate is 8.15m ² , and the spreading area on the 3003 aluminum plate is 43.06 cm ² , the shear strength of the obtained Cu/Al brazing joint is 42.51MPa, and the self-corrosion potential of the solder is -0.819V.

Example 10: The components by weight percentage are: Zn 8.2%, Al 0.2%, Ag 0.55%, P 0.01%, Ni 1%, RE 0.5%, and the balance is Sn. The alloy smelting method and performance testing method are the same as in Example 1. The solidus of the lead-free solder obtained by the above ratio is 203.83°C, and the liquidus is at 214.62°C. With the commercially available flux, the spreading area on the TP2 copper plate is 8.2m ² , and the spreading area on the 3003 aluminum plate is 43.11 cm ² , the shear strength of the obtained Cu/Al brazing joint is 43.12MPa, and the self-corrosion potential of the solder is -0.753V.

Claims (3)

1. Sn-Zn base leadless solder alloy that is used for the aluminum bronze solder; It is characterized in that: said Sn-Zn base leadless solder alloy comprises that following components in weight percentage: Zn is 7-8.5%, and Al is 0.2-0.49%, and Ag is 0.55-0.7%; P is 0-0.1%; Ni is 0-1%, and RE is 0-0.5%, and all the other are Sn.

2. a kind of preparation method who is used for the Sn-Zn base leadless solder alloy of aluminum bronze solder according to claim 1, it is characterized in that: the preparation process may further comprise the steps:

(1) melting Zn-Al intermediate alloy

According to percentage by weight, Al is 6%, and Zn is that to require the block purity of weighing be that 99.99% Metal Zn and purity are 99.99% metal A l to the Zn-Al intermediate alloy of surplus; Under nitrogen or argon shield atmosphere, be warming up to 450-500 ℃ of at first deposite metal Zn, add metal A l then, after fully stirring, be incubated cooling taking-up after 10-15 minute;

(2) melting Sn-Zn base leadless solder alloy

1. to be to use purity be that 99.99% metal Sn, Zn-6Al intermediate alloy, purity are that 99.99% metal A g, purity are that be weight percentage 15% commercially available Sn-P alloy and RE of 99.99% metal Ni, P content smelts in the preparation of Sn-Zn base leadless solder alloy; Each component of components by weight percentage brazing filler metal alloy; Totally 200 grams are placed in the high-temperature resistant tube;

2. use hydrogen flame that high-temperature resistant tube one end scorification is sealed, other end scorification is for thin mouthful and use vavuum pump to vacuumize processing, behind the air in the emptying pipe, with thin mouthful of place's scorification sealing;

3. high-temperature resistant tube is put in the resistance furnace, is heated to 400 ℃ of meltings, treat that all constituent elements all melt after; Be incubated 2-3 hour, during per half an hour high-temperature resistant tube upset is stirred once, make the alloy homogenising; After treating that alloy is even liquid state, cooling is cooled to room temperature, takes out solder.

3. a kind of preparation method who is used for the Sn-Zn base leadless solder alloy of aluminum bronze solder according to claim 2 is characterized in that: said high-temperature resistant tube adopts quartz ampoule or earthenware.