How to Design an Excellent Zinc Alloy Die Casting Mold

Overall Optimization

1. Shorten the cycle time of die casting
2. Improve the service life of die casting mold
3. Reduce scrap rate
4. Reduce energy consumption and use of auxiliary materials
5. Reduce emissions

First of all, the cycle time and service life should be studied in detail, because the maximum potential can be obtained: cycle time is composed of many process steps. The cooling and spraying time adjustment of the mold can accelerate the heat emission, which has the highest optimization potential. The clamping and opening time of the die casting mold is limited by the die casting machine, which cannot be accelerated due to wear and economic reasons. The injection time is very short, which is of secondary importance.

The working life of die casting molds is mainly limited by fatigue cracks. It mainly consists of thermodynamic stress, which must be reduced or the material strength and toughness must be improved in order to improve the working life.
1. Heat balance treatment scheme;
2. Materials;
3. Structure and die casting technology design;
4. Die casting and mechanical parameters;
5. Maintenance plan;
6. Processing;

The heat balance treatment scheme, material, structure and die casting technology design have close interaction with the optimization goal. It is of great significance. The heat balance treatment scheme affects all optimization ranges. By optimizing the heat balance treatment scheme, more heat may be emitted from the die casting mold. This reduces cooling, spraying time and thermodynamic loads. This will not only shorten the cycle time, but also improve the working life of the die casting mold. The heat balance treatment scheme is the focus of all studies.

The heat treatment of materials has influence on several optimization ranges. By improving the thermal conductivity, the cycle time and thermodynamic load will be reduced. Due to the improvement of strength and toughness, the working life can be increased.

The structure and die casting technology have less influence on the optimization range, the thermal stress in the die casting mold is reduced, and its working life is improved.

Analysis of The Scope of Work

1. Heat balance treatment scheme
To improve the heat balance treatment scheme, the cooling and spraying time should be shortened, and the cycle time should be reduced. The shortening of spraying time reduces the thermodynamic load of die casting mold, the amount of release agent and spraying, and the noise and emission.
At present, the cooling path is set in the mold. The device such as distributor hole, one or two spiral cores are set in the selected range to guide the thermostatic treatment medium. In addition to these ordinary thermostatic treatments, there is also a special structure:
– Spot injection cooling;
– Cooling with CO2;
– Heat conducting pipe;
– Inserts in heat balance treatment channels;
– Bushings machined from other materials;

As a well-known technology for industrial use, it is used to process the mold with constant temperature treatment near the contour. The following options are available:
– Laser sintering;
– Sheet metal joints;
– Installation module;
– Modify the die casting mold;
– Spray metal;

2. Heat Balance

For heat balance, the heat cycle shall be studied. The heat input from each cycle to the balance space shall be distributed again in its own cycle. The total amount of all heat flows exceeding the balance limit shall be zero for this initial cycle.
– Thermal energy change and condensation thermal energy change of zinc alloy die castings
– Thermal energy change of spraying medium
– Thermal energy change of heat balance medium

Different die casting molds, machines and zinc alloy die castings will draw different conclusions. When the weight of zinc alloy die castings is large, a small amount of heat energy should be input through the thermostatic treatment device. In addition, the conductive heat energy component to the environment should be reduced, and the heat energy component taken away by the spraying medium will be greatly increased. It can be considered that when the weight of zinc alloy die castings is high, the heat energy component taken away by the spraying will be increased.

3. Methods To Improve Heat Balance Efficiency
Spraying will cause severe heat energy emission of the die casting die, followed by the thermodynamic load of the die casting die. The thermal stress of the material results in thermal fatigue cracks on the surface. Such fatigue cracks are reduced due to the shortening of the spraying time. The ideal mold heat energy should be taken away from the internal heat balance device, rather than the external device.

4. Materials
– Optimization of materials and their properties may reduce cycle time and improve service life.
– Due to the high thermal conductivity of the material, the cycle time and thermal stress can be reduced, and the service life of the die casting mold can be improved.
– Under the conditions of repeatability and the same process, the comparison of different materials and the comparative evaluation of the adaptability to the die casting process can further develop high-performance steels that meet the process.

5. Structure and Casting Technology Design
The working life of the mold is increased due to the reduction of thermodynamic mechanical load by improving the structure and casting technology design.

Optimization scope in structure and die casting technology. The problems raised by the die casting technology should not be studied in detail. The structural design of the mold is determined by its load.

In order to improve the economy of the die casting process, a systematic overall study was made to deal with the key relationships. At the same time, it was confirmed that the heat balance treatment scheme, materials, structure and die casting technology configuration were the main treatment scope, and the heat thinning treatment scheme was of special significance, because there was a strong correlation between the cycle time, service life and the characteristics of zinc alloy die castings. Materials have the potential to improve service life, which is mainly achieved by improving crack resistance and improving thermal conductivity to reduce cycle time. The configuration (design) of structure and die casting technology shows moderate interaction effect. In order to improve the potential recognized by the economic benefits of die casting, appropriate measures should be taken to make it a useful reality.