阅读说明：本技术 一种成本较低且抗拉强度较好的锌合金及其制备方法 (Zinc alloy with low cost and good tensile strength and preparation method thereof ) 是由 梁桂源 梁宗坚 于 2020-06-03 设计创作，主要内容包括：本发明公开了一种成本较低且抗拉强度较好的锌合金及其制备方法,属于锌合金的技术领域,包括一种成本较低且抗拉强度较好的锌合金,其包含以下重量百分比的成分：Al：3.9-4.3%、Cu：0.95-1.25%、Mg：0.06-0.08%、Zn：余量；其中,所述Cu和Al由铜包铝提供。一种成本较低且抗拉强度较好的锌合金的制备方法,其包含以下步骤：加热溶解第一批锌锭得到预制物A；往温度为600-640℃的预制物A中加入铜包铝,待铜包铝溶解后加入锌合金变质剂,待锌合金变质剂溶解后加入第二批锌锭,搅拌溶解得到预制物B；往温度为420-450℃预制物B中加入镁锭,搅拌溶解得到预制物C；保持预制物C的温度在420-450℃,放料、冷却得到锌合金；通过该方法制得的锌合金合格率高、生产效率高且成本较低。(The invention discloses a zinc alloy with lower cost and better tensile strength and a preparation method thereof, belonging to the technical field of zinc alloy, and comprising the following components in percentage by weight: al: 3.9-4.3%, Cu: 0.95-1.25%, Mg: 0.06-0.08%, Zn: the balance; wherein the Cu and Al are provided by copper clad aluminum. A preparation method of zinc alloy with lower cost and better tensile strength comprises the following steps: heating and dissolving a first batch of zinc ingots to obtain a prefabricated object A; adding copper-clad aluminum into the prefabricated object A at the temperature of 600-640 ℃, adding a zinc alloy modifier after the copper-clad aluminum is dissolved, adding a second batch of zinc ingots after the zinc alloy modifier is dissolved, and stirring and dissolving to obtain a prefabricated object B; adding magnesium ingots into the prefabricated object B at the temperature of 420-450 ℃, and stirring and dissolving to obtain a prefabricated object C; keeping the temperature of the prefabricated material C at 420-450 ℃, discharging and cooling to obtain zinc alloy; the zinc alloy prepared by the method has high qualification rate, high production efficiency and lower cost.)

1. The zinc alloy with lower cost and better tensile strength is characterized in that: comprises the following components in percentage by weight:

Al：3.9-4.3%；

Cu：0.95-1.25%；

Mg：0.06-0.08%；

zn: the balance;

wherein the Cu and Al are provided by copper clad aluminum.

2. The zinc alloy of claim 1, wherein the zinc alloy has a low cost and a good tensile strength, and the zinc alloy is characterized in that: the weight ratio of the copper content to the aluminum content in the copper-clad aluminum is 1:4, and the content of impurities in the copper-clad aluminum is less than 0.05%.

3. The zinc alloy of claim 1, wherein the zinc alloy has a low cost and a good tensile strength, and the zinc alloy is characterized in that: the Mg is provided by a magnesium ingot, and the weight percentage of the magnesium in the magnesium ingot is not less than 99.95 percent.

4. The zinc alloy of claim 1, wherein the zinc alloy has a low cost and a good tensile strength, and the zinc alloy is characterized in that: the Zn is provided by a zinc ingot, and the weight percentage of the zinc in the zinc ingot is not less than 99.995%.

5. A method for preparing zinc alloy with lower cost and better tensile strength, which is based on the zinc alloy with lower cost and better tensile strength as claimed in any one of the claims 1-4, and is characterized in that: comprises the following steps:

putting a first batch of zinc ingots into a casting furnace;

starting a casting furnace to heat and dissolve a first batch of zinc ingots to obtain a prefabricated object A;

measuring the temperature of the prefabricated object A, adding copper-clad aluminum into the prefabricated object A at the temperature of 600-640 ℃ after the temperature of the prefabricated object A reaches 600-640 ℃, stirring, adding a zinc alloy modifier after the copper-clad aluminum is dissolved, stirring, adding a second batch of zinc ingots after the zinc alloy modifier is dissolved, stirring, and obtaining a prefabricated object B after the second batch of zinc ingots are dissolved;

measuring the temperature of the prefabricated object B, adding magnesium ingots into the prefabricated object B at the temperature of 420-450 ℃ after the temperature of the prefabricated object B reaches 420-450 ℃, and stirring to uniformly dissolve the magnesium ingots in the prefabricated object B to obtain a prefabricated object C;

keeping the temperature of the prefabricated object C at 420-450 ℃, and then transferring the prefabricated object C into a heat preservation furnace;

discharging, and cooling and solidifying the prefabricated object C to obtain the zinc alloy.

6. The method for preparing the zinc alloy with lower cost and better tensile strength according to claim 5, which is characterized in that: and before adding magnesium ingots, removing scum from the prefabricated material B.

7. The method for preparing the zinc alloy with lower cost and better tensile strength according to claim 5, which is characterized in that: the weight ratio of the first batch of zinc ingots to the second batch of zinc ingots is 3: 2.

8. The method for preparing the zinc alloy with lower cost and better tensile strength according to claim 5, which is characterized in that: and (6) stirring the prefabricated material C in the heat preservation furnace once every 5-10min after discharging for 1 h.

9. The method for preparing the zinc alloy with lower cost and better tensile strength according to claim 5, which is characterized in that: the zinc alloy modifier is an aluminum-titanium zinc alloy modifier.

10. The method for preparing zinc alloy with low cost and good tensile strength according to claim 9, wherein the method comprises the following steps: the addition amount of the aluminum-titanium series zinc alloy alterant accounts for 0.05 to 0.10 percent of the total weight of the raw materials.

Technical Field

The invention relates to the technical field of zinc alloy, in particular to zinc alloy with low cost and good tensile strength and a preparation method thereof.

Background

Zinc is a silvery white metal with metallic luster. Its melting point was 419.5 ℃ and its boiling point was 907 ℃. When zinc is not alloyed, zinc is a softer metal with less strength and hardness than aluminum and copper, and zinc has less recovery characteristics and work hardening. Therefore, zinc cannot be directly used as an engineering material, and other metal elements, such as aluminum, copper, magnesium, cadmium, lead, titanium, etc., need to be added to zinc to form a zinc alloy with relatively high strength and hardness.

Wherein, the effective alloying elements in the zinc alloy comprise aluminum, copper and magnesium. The aluminum can refine grains, improve the strength and impact toughness of the zinc alloy, and obviously reduce the corrosion of molten zinc to an iron container, but the excessive aluminum can influence the strength of the zinc alloy; copper can improve the strength, hardness and corrosion resistance of the zinc alloy, but the added copper can reduce the impact toughness and dimensional stability of the zinc alloy; magnesium can reduce the corrosion of materials in the die-casting zinc alloy and can also eliminate the harmful effects of impurities such as lead, tin and the like, but in the actual production process, if the content of magnesium is too much, the zinc alloy can generate hot brittleness, the tensile strength of the zinc alloy is reduced, and the casting is difficult.

At present, the existing zinc alloy generally comprises the following components in percentage by weight: aluminum: 3.8 to 4.3 percent; copper: 0.010-0.030%; magnesium: 0.035 to 0.05 percent; zinc: and (4) the balance. Wherein the aluminum in the prior art is provided by an aluminum ingot, the copper is provided by a copper bar, the magnesium is provided by a magnesium ingot, the zinc is provided by a zinc ingot, and the Brinell hardness of the zinc alloy in the prior art is about 80, and the tensile strength is 150-170N/mm²It is generally used for the manufacture of toys, lamps, ornaments and the like.

However, the zinc alloy is not suitable for manufacturing automobile parts, because the tensile strength of the automobile parts to the zinc alloy is generally required to be 200N/mm²Left and right. When the tensile strength of the zinc alloy is too low, the quality of the automobile parts is affected, and when the tensile strength of the zinc alloy is too high, the manufacturing cost of the automobile parts is increased.

The tensile strength of the zinc alloy can be adjusted by increasing the weight percentage of copper and magnesium, i.e. adding more copper rods and magnesium ingots in proper amount, however, the melting point of copper is generally 1083 ℃, and when melting copper ingots, a casting furnace for producing the zinc alloy needs to be heated to a higher temperature. This, however, not only leads to an increase in the electricity costs, but also to an increase in the maintenance costs of the furnace. Therefore, it is desirable to provide a zinc alloy that is less costly and suitable for use in making automotive parts.

Disclosure of Invention

In view of the deficiencies of the prior art, it is a first object of the present invention to provideThe zinc alloy with lower cost and better tensile strength has the tensile strength of more than 200N/mm²Left and right sides, can be used to make auto parts.

The second purpose of the invention is to provide a preparation method of zinc alloy with low cost and good tensile strength, which has the advantages of high production efficiency, high qualification rate of zinc alloy and low cost.

In order to achieve the first object, the invention provides the following technical scheme:

the zinc alloy with lower cost and better tensile strength comprises the following components in percentage by weight:

Al：3.9-4.3％；

Cu：0.95-1.25％；

Mg：0.06-0.08％；

zn: the balance;

wherein the Cu and Al are provided by copper clad aluminum.

Preferably, the zinc alloy with lower cost and better tensile strength comprises the following components in percentage by weight:

Al：3.9-4.3％；

Cu：0.975-1.075％；

Mg：0.06-0.08％；

zn: the balance;

wherein the Cu and Al are provided by copper clad aluminum.

By adopting the technical scheme, the zinc has high specific gravity and good casting performance, can be used for die-casting a precise part and also can be subjected to surface treatment, has a low melting point, and is easy to cast and form at about 420 ℃; the aluminum can increase the fluidity of the zinc alloy and improve the casting performance of the zinc alloy, and the aluminum can refine crystal grains to cause solid solution strengthening, thereby improving the mechanical performance of the zinc alloy, but the aluminum content in the zinc alloy should be controlled between 3.9 and 4.3 percent, when the aluminum content is less than 3.9 percent, the fluidity of the zinc alloy liquid is poor, and when the aluminum content exceeds 4.3 percent, the zinc alloy is easy to become brittle, so the use of the zinc alloy is influenced; copper can increase the hardness and tensile strength of the zinc alloy and improve the intergranular corrosion and wear resistance of the zinc alloy, but when the copper content in the zinc alloy is less than 0.95%, the hardness and tensile strength of the zinc alloy are low, and when the copper content in the zinc alloy exceeds 1.25%, the tensile strength and hardness of the zinc alloy are easy to be gradually reduced along with the prolonging of time; magnesium can refine alloy structure and improve the tensile strength of the zinc alloy and the abrasion resistance of the zinc alloy, but when the magnesium content in the zinc alloy is lower than 0.06%, the corrosion resistance and the tensile strength of the zinc alloy are reduced; when the magnesium content in the zinc alloy is higher than 0.08%, the zinc alloy is easy to generate a hot brittleness phenomenon;

in addition, aluminum and copper in the zinc alloy are provided by copper-clad aluminum, the price of the copper-clad aluminum raw material is lower than that of pure copper or pure aluminum, and the copper-clad aluminum is one of aluminum-copper alloys, and the melting point of the copper-clad aluminum is about 600-640 ℃; in general, the melting point of pure aluminum is about 660 ℃, the melting point of pure copper is about 1083 ℃, when pure copper or pure aluminum is adopted to provide copper or aluminum components in aluminum alloy, the temperature in the casting furnace needs to be raised to a higher temperature, and the overhigh temperature is easy to increase the power consumption and the maintenance cost of the casting furnace and can influence the service life of the casting furnace; secondly, the production efficiency of the zinc alloy is reduced because a longer heating time is required for an excessively high melting temperature; according to the invention, copper and aluminum are introduced by adopting copper-clad aluminum, so that the zinc alloy with proper tensile strength is obtained, and meanwhile, the production cost of the zinc alloy is reduced.

Further: the weight ratio of the copper content to the aluminum content in the copper-clad aluminum is 1:4, and the content of impurities in the copper-clad aluminum is less than 0.05%.

By adopting the technical scheme, when the weight ratio of the copper content to the aluminum content in the copper-clad aluminum is 1:4, when the addition amount of any one of the copper or the aluminum is determined, the addition amount of the other component is also in the range, so that the workload is reduced; in addition, the content of impurities in the copper-clad aluminum is less than 0.05%, which is beneficial to reducing the content of impurity elements in the zinc alloy, thereby delaying the intergranular corrosion of the zinc alloy in a warm and humid environment and reducing the problem of surface bubbling of the zinc alloy.

Further: the Mg is provided by a magnesium ingot, and the weight percentage of the magnesium in the magnesium ingot is not less than 99.95 percent.

By adopting the technical scheme, Mg is provided by the magnesium ingot, the weight percentage of the magnesium in the magnesium ingot is not less than 99.995%, and the content of impurity elements in the zinc alloy is favorably reduced, so that the intergranular corrosion of the zinc alloy in a warm and humid environment is delayed, and the problem of surface bubbling of the zinc alloy is reduced.

Further: the Zn is provided by a zinc ingot, and the weight percentage of the zinc in the zinc ingot is not less than 99.995%.

By adopting the technical scheme, Zn is provided by the zinc ingot, the weight percentage of the zinc in the zinc ingot is greater than or equal to 99.995%, and the content of impurity elements in the zinc alloy is favorably reduced, so that the intergranular corrosion of the zinc alloy in a warm and humid environment is delayed, and the problem of surface bubbling of the zinc alloy is reduced.

A preparation method of zinc alloy with lower cost and better tensile strength is based on any one of the zinc alloy with lower cost and better tensile strength, and comprises the following steps:

(1) putting a first batch of zinc ingots into a casting furnace;

(2) starting a casting furnace to heat and dissolve a first batch of zinc ingots to obtain a prefabricated object A;

(3) measuring the temperature of the prefabricated object A, adding copper-clad aluminum into the prefabricated object A at the temperature of 600-640 ℃ after the temperature of the prefabricated object A reaches 600-640 ℃, stirring, adding a zinc alloy modifier after the copper-clad aluminum is dissolved, stirring, adding a second batch of zinc ingots after the zinc alloy modifier is dissolved, stirring, and obtaining a prefabricated object B after the second batch of zinc ingots are dissolved;

(4) measuring the temperature of the prefabricated object B, adding magnesium ingots into the prefabricated object B at the temperature of 420-450 ℃ after the temperature of the prefabricated object B reaches 420-450 ℃, and stirring to uniformly dissolve the magnesium ingots in the prefabricated object B to obtain a prefabricated object C;

(5) keeping the temperature of the prefabricated object C at 420-450 ℃, and then transferring the prefabricated object C into a heat preservation furnace;

(6) discharging, and cooling and solidifying the prefabricated object C to obtain the zinc alloy.

By adopting the technical scheme, the zinc ingots are added in two batches, the first batch of zinc ingots are fed in the cooling furnace, and the melting point of the zinc ingots is lower, so that the protection of the casting furnace is facilitated, and the service life of the casting furnace is prolonged; feeding the second batch of zinc ingots after the copper-clad aluminum and the zinc alloy modifier are dissolved, so that the zinc, the aluminum and the copper can be uniformly mixed; when the copper clad aluminum is added, the temperature of the zinc liquid is required to be 600-640 ℃, which is beneficial to ensuring that the copper clad aluminum can be completely melted; after the copper clad aluminum is completely melted, adding a zinc alloy modifier to modify the zinc alloy liquid, wherein the modification is a method for adding a small amount of active substances into the metal liquid to promote nucleation inside the liquid metal or change the crystal growth process, and can effectively prevent the zinc alloy from cracking; in addition, the zinc alloy alterant can promote impurities in the zinc alloy liquid to float on the surface, which is beneficial to improving the quality of the zinc alloy; the magnesium ingot is added finally, and when the magnesium ingot is added, the temperature of the prefabricated material B is required to be 420-450 ℃, on one hand, when the temperature of the magnesium ingot is too high, the oxidation burning loss rate of magnesium is easy to increase, on the other hand, because a large amount of heat is emitted when the magnesium ingot is melted, the temperature of the zinc alloy liquid is lower than the melting point of pure magnesium when the magnesium ingot is added; during material discharging, the temperature of the prefabricated material C is kept at 420-450 ℃, so that the fluidity of the prefabricated material C is ensured, and the effect of facilitating material discharging is achieved.

Further: and before adding magnesium ingots, removing scum from the prefabricated material B.

By adopting the technical scheme, when the scum floats on the surface of the zinc alloy liquid, the dissolution of the magnesium ingot is easily influenced, and the oxidation burning loss rate of the magnesium ingot is increased, so that before the magnesium ingot is put into the furnace, the scum removing treatment is firstly carried out on the prefabricated object B, the burning loss rate of the magnesium ingot is favorably reduced, and the utilization efficiency of the magnesium ingot is improved.

Further: the weight ratio of the first batch of zinc ingots to the second batch of zinc ingots is 3: 2.

By adopting the technical scheme, the zinc ingots are added in two batches, the first batch of zinc ingots are fed in the cooling furnace, and the melting point of the zinc ingots is lower, so that the protection of the casting furnace is facilitated, and the service life of the casting furnace is prolonged; feeding the second batch of zinc ingots after the copper-clad aluminum and the zinc alloy modifier are dissolved, so that the zinc, the aluminum and the copper can be uniformly mixed; in addition, the weight ratio of the first batch of zinc ingots to the second batch of zinc ingots is 3:2, the temperature is more convenient to control, namely after the second batch of zinc ingots are melted, the temperature of the prefabricated object B is just in the range of 420-450 ℃, and the prefabricated object B does not need to be additionally subjected to temperature reduction or reheated, so that the production efficiency of the zinc alloy is improved, and the production cost of the zinc alloy is reduced.

Further: and (6) stirring the prefabricated material C in the heat preservation furnace once every 5-10min after discharging for 1 h.

By adopting the technical scheme, the density of the zinc liquid is higher than that of other metal elements, and when the heat preservation time of the zinc alloy liquid is too long, the zinc alloy liquid can be layered, so that the zinc alloy liquid needs to be stirred during heat preservation, the zinc alloy liquid is uniformly mixed, and the improvement of the quality of the zinc alloy is facilitated.

Further: the zinc alloy modifier is an aluminum-titanium zinc alloy modifier.

By adopting the technical scheme, titanium is an element with a strong grain refining effect, can effectively prevent the zinc alloy from cracking, is particularly suitable for the Zn-Al-Cu-Mg alloy which is easy to generate casting cracks, and is beneficial to improving the tensile strength and corrosion resistance of the zinc alloy, thereby reducing the generation of waste products.

Further: the addition amount of the aluminum-titanium series zinc alloy alterant accounts for 0.05 to 0.10 percent of the total weight of the raw materials.

By adopting the technical scheme, the addition amount of the aluminum-titanium series zinc alloy modifier is 0.05-0.10%, when the addition amount of the aluminum-titanium series zinc alloy modifier is less than 0.02%, the corrosion resistance, the tensile strength and the hardness of the zinc alloy are weakened, and when the addition amount of the aluminum-titanium series zinc alloy modifier is less than 0.10%, the corrosion resistance, the tensile strength and the hardness of the zinc alloy are not greatly changed, and the production cost is easily increased by continuously increasing the addition amount of the aluminum-titanium series zinc alloy modifier.

In conclusion, the invention has the following beneficial effects:

firstly, aluminum and copper in the zinc alloy are provided by copper-clad aluminum, the price of the copper-clad aluminum is lower than that of pure copper or pure aluminum, the copper-clad aluminum is one of aluminum-copper alloys, and the melting point of the copper-clad aluminum is about 600-640 ℃; in general, the melting point of pure aluminum is about 660 ℃, the melting point of pure copper is about 1083 ℃, when pure copper or pure aluminum is adopted to provide copper or aluminum components in aluminum alloy, the temperature in the casting furnace needs to be raised to a higher temperature, and the overhigh temperature is easy to increase the power consumption and the maintenance cost of the casting furnace and can influence the service life of the casting furnace; secondly, the production efficiency of the zinc alloy is reduced because a longer heating time is required for an excessively high melting temperature; according to the invention, copper and aluminum are introduced by adopting copper-clad aluminum, so that the zinc alloy with proper tensile strength is obtained, and meanwhile, the production cost of the zinc alloy is reduced;

secondly, the zinc ingots are added in two batches, the zinc ingots in the first batch are fed in a cold furnace, and the melting point of the zinc ingots is lower, so that the protection of the casting furnace is facilitated, and the service life of the casting furnace is prolonged; feeding the second batch of zinc ingots after the copper-clad aluminum and the zinc alloy modifier are dissolved, so that the zinc, the aluminum and the copper can be uniformly mixed; in addition, the weight ratio of the first batch of zinc ingots to the second batch of zinc ingots is 3:2, the prefabricated object B does not need to be additionally cooled down or heated again, so that the production efficiency of the zinc alloy is improved, and the production cost of the zinc alloy is reduced.

Detailed Description

Source of raw materials

The sources of the raw materials used in this example are shown in table 1 below:

TABLE 1 sources of raw materials