Copper has high hardness and strong corrosion resistance. It has good mechanical properties, wear-resistance and strength close to that of steel Conventional hot work die steels can be, for example, H13, SKD61, dh-31s, 8407, W302. Due to the high temperature of the alloy liquid in the production of copper alloy die casting, the mold is more prone to thermal fatigue and cracking. Now some materials with heat shock resistance will be better. The process of organically combining and applying the three die-casting production factors of die-casting copper alloy, die-casting die and die-casting machine. Next, let’s look at the requirements for copper die casting materials.

Requirements for copper die casting materials:

1.When the thermal temperature is not high, it has good fluidity, which is convenient for filling complex cavities to obtain castings with good surface quality.

2.The linear shrinkage and crack tendency are small, so as to avoid cracks in the casting and improve the dimensional accuracy of the casting.

3.The crystallization temperature range is small to avoid shrinkage cavity and porosity and improve the quality of castings.

4.It has certain high-temperature strength to avoid deformation or fragmentation when pushing out the casting.

5.It has high strength at room temperature to meet the needs of the production of large thin-wall complex castings.

6.The tendency of physical-chemical interaction with metal cavities is small, so as to reduce mucosa and alloying with each other.

7.It has good processing function and certain corrosion resistance.

 

Methods of copper die casting: injection specific pressure and injection speed, pouring temperature and molding temperature.

Injection specific pressure and injection velocity

The selection of injection specific pressure shall be determined according to the structural characteristics of different alloys and castings; For the selection of filling speed, generally for castings with thick wall or high internal quality requirements, lower filling speed and high pressurization pressure should be selected; For castings with thin wall or high surface quality requirements and complex castings, higher proportion and high filling speed should be selected.

 

Pouring temperature

Pouring temperature refers to the average temperature of liquid metal when entering the mold cavity from the pressure setting. Because it is inconvenient to measure the temperature of liquid metal in the pressure chamber, it is generally expressed by the temperature in the holding furnace.

High pouring temperature and large shrinkage make the casting easy to produce cracks, large grains, and sticking mold; The pouring source is too low, which is easy to produce defects such as cold insulation, surface pattern, and insufficient pouring. Therefore, the pouring temperature should be considered simultaneously with the pressure, die-casting mold temperature, and filling speed.

 

Die temperature

In continuous production, the temperature of die-casting mold often increases, especially for die-casting high melting point alloy. High temperature not only makes the liquid metal stick but also makes the casting cool slowly and makes the grain coarser. Therefore, cooling measures should be taken when the die casting temperature is too high. It is usually cooled with compressed air, water, or a chemical medium.

 

Die casting machine is used in the process of copper die casting, so let’s say the environmental requirements of die casting machine:

1.Keep the die casting machine and its surrounding environment clean.

2.The space near the die casting machine shall be unblocked, the ventilation and ventilation equipment shall be in good working condition, and the materials and auxiliary appliances shall be placed according to the requirements of fixed location management.

3.After adding hydraulic oil or lubricating oil, wipe off the leaked oil as soon as possible.

4.Work carefully and put safety first. Irrelevant personnel are not allowed to enter the operation area.

 

Precautions for die casting machine in copper die casting processing:

Before startup

1.Check whether the safety door is flexible and whether the front and rear safety threshold switches (Kyrgyzstan system) are normal: turn on the power switch of the machine, close the front and rear safety doors, and observe the corresponding output signal lamp of PLC in the electrical box. If the lamp is on, it indicates normal. If the lamp is not on, stop the machine to check the corresponding circuit.

2.Check that the emergency stop button is normal, and check that the total pressure of the oil pressure system and the settings of various functional parameters should meet the working requirements.

 

Starting up

1.It is forbidden to put your hand into the die casting machine (mold) or take materials from it with your bare hands.

2.Without permission, it is forbidden to arbitrarily adjust the set parameters of the machine, which should be adjusted by professionals.

3.When the machine breaks down or the alarm signal rings, stop the machine immediately, cut off the power supply, open the protective door, and then repair the machine.

4.High quality die-casting alloy ingots shall be selected to avoid putting the alloy containing moisture and oil stains into the furnace.

5.The recycled material of alloy ingot needs special treatment to recognize that its chemical composition meets the demand before it can be reused. It is not allowed to put the slag directly into the furnace.

 

Inspection items of die casting machine in copper die casting processing:

1.In case of emergency shutdown, check whether the power supply of control system and motor can be cut off.

2.Check that the central lubrication system should be intact. It should be able to automatically transfer oil when starting up and automatically transfer oil according to the set requirements when working.

3.Check that the furnace temperature control system should be normal.

4.Test and check with manual / full-automatic conditions respectively. When the safety door is swung open or half swung open, the locking (mold and movement) shall be terminated.

5.Check that the working pressure of the hydraulic system should meet the requirements of the machine specification.

6.Check whether the moulds and tools are firmly installed on the fixed base plate and the movable base plate.

7.After starting up for a period of time, check the oil temperature. The oil temperature shall not exceed 55 ℃ during long-term operation.

8.Check whether the safety threshold switch (Kyrgyzstan system) is normal.

9.Check that the grounding wire in the main electrical box should be intact.

10.Check it every day.