Die-cast zinc alloy
Time：2017-10-25 10:22:17 Hit：
Cast zinc alloy
Zinc alloys are alloys based on zinc and added to other elements. Commonly added alloying elements include low-temperature zinc alloys such as aluminum, copper, magnesium, cadmium, lead, and titanium. Zinc alloy has low melting point, good fluidity, easy fusion welding, brazing and plastic processing. It is resistant to corrosion in the atmosphere, and the residual waste is easy to recover and remelt; but the creep strength is low, and it is easy to cause dimensional changes caused by natural aging. Prepared by melt, die cast or pressure processed into a material.
According to the manufacturing process, it can be divided into cast zinc alloy and deformed zinc alloy. The main added elements of zinc alloy are aluminum, copper and magnesium. Zinc alloy can be divided into two types: deformation and cast zinc alloy according to the processing technology. Casting zinc alloy has good fluidity and corrosion resistance, suitable for die-casting instruments, automotive parts and shells. Wait.
Characteristics
1. Relatively significant.
2. The casting performance is good, and the precision parts with thin shapes and thin walls can be die-casted, and the surface of the casting is smooth.
3. Surface treatment: electroplating, spraying, painting, polishing, grinding, etc.
4. No iron is absorbed during melting and die casting, no corrosion is applied, and no mold is applied.
5. Has good mechanical properties and wear resistance at room temperature.
6. Low melting point, melting at 385 ° C, easy to die casting.
kind
The traditional die-cast zinc alloys are alloys 2, 3, 4, 5, and 7. The most widely used zinc alloy is No. 3. In the 1970s, high-aluminum-zinc-based alloys ZA-8, ZA-12, and ZA-27 were developed.
Zamak 3: Good flow and mechanical properties.
It is applied to castings that do not require high mechanical strength, such as toys, lamps, decorations, and some electrical components.
Zamak 5: Good fluidity and good mechanical properties.
It is applied to castings that have certain requirements on mechanical strength, such as auto parts, electromechanical parts, mechanical parts, and electrical components.
Zamak 2: Mechanical parts for general requirements on mechanical properties, high hardness requirements, good wear resistance and dimensional accuracy requirements.
ZA8: Has good impact strength and dimensional stability, but has poor fluidity.
Low temperature zinc alloy
It is applied to workpieces with small size, precision and mechanical strength, such as electrical components.
Superloy: The best fluidity, used in die-casting thin-walled, large-size, high-precision, complex-shaped workpieces, such as electrical components and their boxes.
Different zinc alloys have different physical and mechanical properties, which provides a choice for die casting design.
According to the manufacturing process, zinc alloy can be divided into two types: cast zinc alloy and deformed zinc alloy. The yield of cast alloys is much greater than that of deformed alloys. The composition, properties and uses of several important zinc alloys are listed in the table below.
Cast zinc alloys are divided into pressure-cast zinc alloys (solidified under external pressure) and gravity-cast zinc alloys (solidified only by gravity) depending on the casting method.
Die Casting Zinc Alloys Since the application of this alloy in the automotive industry in 1940, the output has increased dramatically. About 25% of the total zinc consumption is used to produce this alloy. Advanced and applicable technologies are being continuously adopted and developed rapidly. Corresponding related talents are also increasing, and there are a complete collection of steel talents. The most commonly used alloy is the Zn-Al-Cu-Mg system. Certain impurities significantly affect the properties of die-cast zinc alloys. Therefore, the content of impurities such as iron, lead, cadmium and tin is extremely strict, and the upper limit is 0.005%, 0.004%, 0.003%, and 0.02%, respectively. Therefore, the zinc alloy for die casting should use high purity zinc with a purity greater than 99.99% as a raw material.
Gravity cast zinc alloys can be cast in sand, plaster or hard molds. This zinc alloy not only has the characteristics of general die-cast zinc alloy, but also has high strength and good casting performance. The cooling rate has no obvious influence on mechanical properties. Residues and scraps can be recycled, the gate is simple, and it is not sensitive to overheating and remelting. The rate is small, the pores are small, and the plating can be performed by conventional methods.
In addition to the traditional varieties, Zn-1Cu-0.1Ti and Zn-22Al alloys have appeared in the deformed zinc alloy industry. After the former alloy is rolled, the grain boundary moves can be hindered due to the arrangement of the dispersed particles of the TiZn15 intermetallic compound along the rolling direction.
Zinc alloy selection
Which zinc alloy to choose, mainly considering three aspects
1. The use of the die casting itself requires the performance requirements to be met. include:
(1) Mechanical properties, tensile strength, is the maximum resistance when the material breaks;
Elongation is a measure of material brittleness and plasticity;
Hardness is the resistance of the surface of the material to the plastic deformation caused by the intrusion or friction of the hard material.
(2) Working environment status: working temperature, humidity, medium in contact with the workpiece and air tightness requirements.
(3) Accuracy requirements: Accuracy and dimensional stability that can be achieved.
2. Good process performance: (1) casting process;
(2) Machining processability;
(3) Surface treatment processability.
3. 3. Good economy: the cost of raw materials and the requirements for production equipment (including melting equipment, die casting machines, molds, etc.), as well as production costs.
Zinc alloys are alloys based on zinc and added to other elements. Commonly added alloying elements include low-temperature zinc alloys such as aluminum, copper, magnesium, cadmium, lead, and titanium. Zinc alloy has low melting point, good fluidity, easy fusion welding, brazing and plastic processing. It is resistant to corrosion in the atmosphere, and the residual waste is easy to recover and remelt; but the creep strength is low, and it is easy to cause dimensional changes caused by natural aging. Prepared by melt, die cast or pressure processed into a material.
According to the manufacturing process, it can be divided into cast zinc alloy and deformed zinc alloy. The main added elements of zinc alloy are aluminum, copper and magnesium. Zinc alloy can be divided into two types: deformation and cast zinc alloy according to the processing technology. Casting zinc alloy has good fluidity and corrosion resistance, suitable for die-casting instruments, automotive parts and shells. Wait.
Characteristics
1. Relatively significant.
2. The casting performance is good, and the precision parts with thin shapes and thin walls can be die-casted, and the surface of the casting is smooth.
3. Surface treatment: electroplating, spraying, painting, polishing, grinding, etc.
4. No iron is absorbed during melting and die casting, no corrosion is applied, and no mold is applied.
5. Has good mechanical properties and wear resistance at room temperature.
6. Low melting point, melting at 385 ° C, easy to die casting.
kind
The traditional die-cast zinc alloys are alloys 2, 3, 4, 5, and 7. The most widely used zinc alloy is No. 3. In the 1970s, high-aluminum-zinc-based alloys ZA-8, ZA-12, and ZA-27 were developed.
Zamak 3: Good flow and mechanical properties.
It is applied to castings that do not require high mechanical strength, such as toys, lamps, decorations, and some electrical components.
Zamak 5: Good fluidity and good mechanical properties.
It is applied to castings that have certain requirements on mechanical strength, such as auto parts, electromechanical parts, mechanical parts, and electrical components.
Zamak 2: Mechanical parts for general requirements on mechanical properties, high hardness requirements, good wear resistance and dimensional accuracy requirements.
ZA8: Has good impact strength and dimensional stability, but has poor fluidity.
Low temperature zinc alloy
It is applied to workpieces with small size, precision and mechanical strength, such as electrical components.
Superloy: The best fluidity, used in die-casting thin-walled, large-size, high-precision, complex-shaped workpieces, such as electrical components and their boxes.
Different zinc alloys have different physical and mechanical properties, which provides a choice for die casting design.
According to the manufacturing process, zinc alloy can be divided into two types: cast zinc alloy and deformed zinc alloy. The yield of cast alloys is much greater than that of deformed alloys. The composition, properties and uses of several important zinc alloys are listed in the table below.
Cast zinc alloys are divided into pressure-cast zinc alloys (solidified under external pressure) and gravity-cast zinc alloys (solidified only by gravity) depending on the casting method.
Die Casting Zinc Alloys Since the application of this alloy in the automotive industry in 1940, the output has increased dramatically. About 25% of the total zinc consumption is used to produce this alloy. Advanced and applicable technologies are being continuously adopted and developed rapidly. Corresponding related talents are also increasing, and there are a complete collection of steel talents. The most commonly used alloy is the Zn-Al-Cu-Mg system. Certain impurities significantly affect the properties of die-cast zinc alloys. Therefore, the content of impurities such as iron, lead, cadmium and tin is extremely strict, and the upper limit is 0.005%, 0.004%, 0.003%, and 0.02%, respectively. Therefore, the zinc alloy for die casting should use high purity zinc with a purity greater than 99.99% as a raw material.
Gravity cast zinc alloys can be cast in sand, plaster or hard molds. This zinc alloy not only has the characteristics of general die-cast zinc alloy, but also has high strength and good casting performance. The cooling rate has no obvious influence on mechanical properties. Residues and scraps can be recycled, the gate is simple, and it is not sensitive to overheating and remelting. The rate is small, the pores are small, and the plating can be performed by conventional methods.
In addition to the traditional varieties, Zn-1Cu-0.1Ti and Zn-22Al alloys have appeared in the deformed zinc alloy industry. After the former alloy is rolled, the grain boundary moves can be hindered due to the arrangement of the dispersed particles of the TiZn15 intermetallic compound along the rolling direction.
Zinc alloy selection
Which zinc alloy to choose, mainly considering three aspects
1. The use of the die casting itself requires the performance requirements to be met. include:
(1) Mechanical properties, tensile strength, is the maximum resistance when the material breaks;
Elongation is a measure of material brittleness and plasticity;
Hardness is the resistance of the surface of the material to the plastic deformation caused by the intrusion or friction of the hard material.
(2) Working environment status: working temperature, humidity, medium in contact with the workpiece and air tightness requirements.
(3) Accuracy requirements: Accuracy and dimensional stability that can be achieved.
2. Good process performance: (1) casting process;
(2) Machining processability;
(3) Surface treatment processability.
3. 3. Good economy: the cost of raw materials and the requirements for production equipment (including melting equipment, die casting machines, molds, etc.), as well as production costs.
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