Zinc alloy die casting

0010010 nbsp;

Metal die-casting gearproduct description

The traditional die-cast zinc alloys are 2, 3, 4, {{3}}, 7 alloys, the most widely used are {{1 }} Zinc alloy. In the 1970s, high-aluminum zinc-based alloys ZA-8, ZA-1 2, ZA-2 7 were developed.
Zamak 3: Good fluidity and mechanical properties.

Used in castings that do not require high mechanical strength, such as toys, lamps, decorations, some electrical devices, and coffee machine hardware accessories.

Zamak 5: Good fluidity and good mechanical properties.

Used in castings with certain requirements on mechanical strength, such as auto parts, electromechanical parts, mechanical parts, electrical components, mixer hardware parts.

Zamak 2: It is used for mechanical parts with special requirements on mechanical properties, high hardness, good wear resistance and general dimensional accuracy.

ZA 8: Has good impact strength and dimensional stability, but poor fluidity.

Low temperature zinc alloy

It is used for workpieces with small size, high precision and mechanical strength, such as electrical devices.

Superloy: It has the best fluidity and is applied to die-casting thin-walled, large-sized, high-precision, and 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 alloys can be divided into cast zinc alloys and deformed zinc alloys. The output of cast alloy is much larger than that of deformed alloy. The following table lists the composition, properties and uses of several important zinc alloys.

According to different casting methods, casting zinc alloys are divided into pressure casting zinc alloys (solidified under the action of applied pressure) and gravity casting zinc alloys (solidified only under the action of gravity).

The pressure casting zinc alloy, which has been used in the automotive industry since 1940 years, has seen a sharp increase in production. About 25% of the total zinc consumption is used to produce this alloy. Advanced and applicable technologies are constantly being adopted and developed rapidly. Corresponding related talents are also increasing, and the steel talent network with complete collection is included. The most commonly used alloy system is Zn-Al-Cu-Mg system. Certain impurities significantly affect the performance of die-cast zinc alloys. Therefore, the content of impurities such as iron, lead, cadmium and tin is extremely restricted, and the upper limits are 0. 005%, 0. 004%, 0. 003%, 0. 02%, so high purity zinc with a purity greater than 99. 99% should be used as the raw material for die-casting zinc alloys.

Gravity casting zinc alloy can be cast in sand mold, gypsum mold or hard mold. This zinc alloy not only has the characteristics of general die-casting zinc alloy, but also has high strength, good casting performance, cooling speed has no obvious effect on mechanical properties, residual and scrap can be recycled, the gate is simple, insensitive to overheating and remelting, shrinkage The rate is small, the pores are few, can be electroplated, and can be finished by conventional methods.

In addition to the traditional varieties of deformed zinc alloys used in the deformed zinc alloy industry, Zn-Cu-0. 1 Ti and Zn-22Al alloys have appeared. After the former alloy is rolled, TiZn 1 5 intermetallic compound dispersed particles are arranged in a row along the rolling direction, which can hinder the movement of grain boundaries.

select
Which kind of zinc alloy to choose, mainly from three aspects to consider

1. The purpose of the die-casting part itself needs to meet the performance requirements. include:

(1) The mechanical properties and tensile strength are the maximum resistance of the material when it breaks;

Elongation is a measure of material brittleness and plasticity;

Hardness is the resistance of the material surface to plastic deformation caused by hard objects being pressed or rubbed.

(2) Working environment status: working temperature, humidity, medium and airtightness requirements of workpiece contact.

(3) Accuracy requirements: Achievable accuracy and dimensional stability

2. Good process performance:

(1) casting process;

(2) Mechanical processing technology;

(3) Surface treatment processability.

3. Good economy: the cost of raw materials and the requirements for production equipment (including melting equipment, die casting machines, molds, etc.), and production costs.

Features:
1. Relatively large.

2. The casting performance is good. It can die-cast precision parts with complex shapes and thin walls.
3. Surface treatment is possible: electroplating, spraying, painting, polishing, grinding, etc.

4. It does not absorb iron during melting and die casting, does not corrode the mold, and does not stick to the mold.

5. Has good mechanical properties and wear resistance at room temperature.

6. It has a low melting point and melts at 385 ° C, making it easy to die cast.