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Zinc aluminum alloy die casting mold development cycle
- 2019-04-08-

Due to its ease of use, rapid cycling and low melting temperature (400 to 500 ° C), zinc alloys are increasingly used in different manufacturing industries: from furniture to iron From clothing to mechanical parts, automobiles, electronics, pneumatics, hydraulics, etc.

The use of zinc alloy die casting to replace other materials has many advantages and advantages, including:

• 0010010 nbsp; Production speed: Compared with other processes and materials, zinc alloy die casting is characterized by higher productivity per hour. This is possible because the cooling time required for zinc alloys is significantly shortened. Depending on the size of the precision casting, it can achieve double the speed compared to aluminum or plastic. The developed multi-sliding hot cell technology allows up to 3500 times / hour (dry).

• 0010010 Energy saving: The relatively low melting temperature reduces the energy requirements for zinc alloy processing. Compared with aluminum, the estimated energy saving is at least 50% and compared with magnesium 15%.

• 0010010 nbsp; Dimensional accuracy: Although the dimensional accuracy mainly depends on the manufacturing process, the material also affects the achievable tolerances. Compared with other three-dimensional processes, die-casting parts can produce tighter tolerances, and the dimensions are usually 10 times more accurate and consistent than extrusion, printing and lost wax casting. Die-cast zinc alloys ensure tolerances that require machining from other materials.
Hundreds of tolerances can be easily obtained, while aluminum only allows double tolerance values ​​and magnesium allows one and a half tolerances.
Compared with aluminum and magnesium, zinc alloys have higher dimensional stability. In addition, they usually require a lower vibration angle for mold extraction. In fact, parallel holes and outer walls can be obtained with a draught of 0. 5 ° instead of the usual 2 ° draught. The holes can be made with such a small taper, making it possible to tap directly.

• 0010010 nbsp; Easy to assemble: Wherever needed, the high ductility of the zinc alloy allows the insertion of foldable, hammered or stepped castings to facilitate assembly of other adjacent parts.

• 0010010 nbsp; Low mold wear: Zinc alloy die casting molds usually last more than two million cycles. Their life is similar to thermoplastic injection molding, that is, about ten times higher than aluminum die-casting, and is generally higher in magnesium die-casting. By adding removable and replaceable inserts, the same mold can be used to obtain similar items, in those cases when it is not economical to build a new mold.
Each project should be carefully evaluated to ensure that equipment is effectively deployed to obtain low unit costs.

• 0010010 nbsp; Safety: Unlike aluminum, especially magnesium, zinc alloys will not cause any fire hazards due to sparks when processing and using die castings.

• 0010010 nbsp; Project complexity: By applying some basic design principles, you can make full use of intelligent lock die casting technology.
The following points should not be considered strict rules, but if used with a grain of salt will help create a consistent, efficient and cost-effective project. Our extensive experience allows us to propose small changes to projects that may significantly affect the efficiency and production economy of specific components.

• 0010010 nbsp; wall thickness
The wall part should be as thin as possible while ensuring resistance and stiffness.
The common size is 1 mm, but the lower size is usually larger than 0. 3 mm.
This helps to reduce the weight of metal required and accelerate solidification into the mold, thereby increasing production speed.

• 0010010 nbsp; corners and joints
Angles and angles should be avoided whenever possible.
Internal joints are critical, and it is often desirable to have joints at the external and internal closed corners. 0. 5 mm joints will have a significant enhancement effect and will hardly attract attention on the outer boundary.

• 0010010 nbsp; insert
Very few geometries cannot be obtained during die casting.
However, the need to use inserts and other features of removable elements in the mold will increase the overall cost. There are some restrictions on internal indentation.

• 0010010 nbsp; noodles
Wide and flat surfaces should be avoided as much as possible. If they are needed, slight bending improves appearance and roughness, while helping to avoid minor surface defects that may affect the overall appearance.

• 0010010 nbsp; thread
External threads are easy to obtain, especially if they appear on the parting line of the mold. The internal thread can also be die-cast, but in general, it is more convenient to tap the holes obtained by die-casting. As an alternative, self-tapping screws can also be used.

• 0010010 nbsp; Surface coating:
Zinc alloy die casting is a direct way to manufacture precise and robust components, and sometimes it is also economical, suitable for various industries. Many products are used in technologically advanced applications and do not require any surface treatment. However, in some cases, the coating needs:

-Get decorative effects
-Improve corrosion resistance
-Increase wear resistance and wear resistance.
The range of zinc alloy die-casting electroplating is very wide, and new finishing processes are constantly being researched and developed.

• 0010010 nbsp; chemical coating
Chemical coatings provide corrosion-resistant surfaces at low cost. They are obtained by immersion or in some cases spraying the components with specific solutions. There are two main types of chemical finishing-chromate conversion coating and phosphate conversion coating. In addition to corrosion protection, they also provide the basis for further organic coatings. There are also colored coatings which can only be used in mildly aggressive environments and / or if the component is subjected to very little treatment. A special anodizing process transforms the zinc surface into a very corrosion-resistant and wear-resistant film. These coatings are only for functional purposes and are usually olive green matte.
Despite their name, they are not like aluminum anodizing because the two processes and the resulting coating have very different characteristics.

• 0010010 nbsp; organic coating
The polished die-cast zinc surface has an aesthetic appearance and can be maintained through the application of organic coatings. These are acrylic / polyurethane paints or polyester powders, which are both transparent and colored. Painted or powder-coated die-cast zinc is commonly used in automotive, household appliances and machine mechanical parts.
In the electrolytic painting process, the coating is partially immersed in a basin (anode) containing a special paint containing soluble resin as the cathode.
In addition to the advantages of regularity of deposited films, this method does not require volatile and flammable organic solvents.
Electrostatic powder coatings are increasingly used as die casting organic coating methods.
After degreasing (and chromium in cases where relatively high corrosion resistance is required), the parts are usually electronically sprayed with epoxy resin or polyester powder and heated to "fluidize" the powder to obtain a solid and sticky protective film. Epoxy coatings have corrosion resistance, while polyester coatings have higher hardness.

• 0010010 nbsp; plating coating
Die-cast zinc alloy parts can be polished using various types of electroplated coatings for aesthetic or protection purposes, or to obtain special electrical or surface characteristics. It is recommended to use copper coatings for aesthetic purposes or to provide highly conductive surfaces for electrical and electronic uses, and to facilitate soldering in some cases. Copper deposits are also used as the basis for other types of coatings. What is commonly referred to as "chrome plating" is actually a coating composed of one or more copper layers, one or more nickel layers, and a chromium layer. When good contact resistance and surface conductivity are required, gold and silver plating (always on copper or nickel substrates) can be used for luxury finishing.
Another commonly used surface treatment is nickel plating.

• 0010010 nbsp; Anti-friction properties: Zinc alloys have good self-lubricating properties and have been used for parts with special properties for many years. They are a good substitute for brass, and are particularly suitable for parts that bear small loads.

• 0010010 nbsp; Anti-vibration and noise reduction performance: the damping capacity of zinc alloy at room temperature is between {{{{5}}}% to 4% This value is higher than 0. 5% of aluminum and {{5}}. 5% of steel. Only the value of gray cast iron is higher, about 7-{{5}} 5%. Compared with aluminum, Zamak also has a higher absorption capacity.

• 0010010 nbsp; Good machine tool machinability:
Zinc alloy die casting allows the design of complex parts, otherwise further expensive machining is required. However, if further processing is required, the parts can be easily handled using ordinary tools.
The level of accuracy currently achievable in zinc alloy die casting almost completely eliminates the need for milling or grinding to obtain a flat surface, which can be directly produced by die casting. However, in some cases, concave parts may require milling and grinding.

• 0010010 nbsp; Good environmental sustainability: Zinc alloys can be fully recycled and reused over time. Most strict industry regulations allow the use of zinc alloys.