1. What is the injection pressure ratio and how to adjust it?

The injection pressure ratio is the pressure of the molten metal in the pressure chamber per unit area. Under the premise of ensuring product quality, try to use a lower pressure ratio. The pressure ratio of lamp die casting is generally below 50MPA. The thicker the product wall, the higher the pressure ratio requirement. The more complex the product structure, the higher the pressure ratio requirement.

2. What is the injection speed? How to adjust the injection speed?

The injection speed refers to the speed at which the injection head moves during die casting, which is divided into slow injection speed and fast injection speed. The injection speed generally refers to the fast injection speed. The size of the slow injection speed is suitable for the injection head to not splash the metal liquid when passing through the gate. It is generally 0.1~0.5M/S, and the fast injection speed of aluminum alloy is generally 0.1~1.1M/S. The thinner the wall thickness of the casting, the faster the injection speed. The more complex the shape of the casting, the faster the injection speed. The larger the projection surface of the casting, the faster the injection speed. The longer the casting filling distance, the faster the injection speed.

3. What is the pouring temperature? How to choose the pouring temperature?

The pouring temperature generally refers to the average temperature when the molten metal is poured into the injection chamber and fills the cavity. Usually, the lowest possible temperature is used under the premise of ensuring molding and the required surface quality. The pouring temperature of aluminum alloy is 650℃~720℃. The casting alloy has good fluidity and the pouring temperature can be lower; the pouring temperature of thin-walled and complex-shaped castings can be higher; the mold is larger and the heat dissipation is fast, so the pouring temperature can be higher.

4. What is the mold temperature? What is the mold temperature during normal production of aluminum alloy die-casting molds?

The mold temperature is the temperature of the mold during the production process. The temperature of the aluminum alloy die-casting mold during normal production is: 200℃~280℃. Generally, the thinner the casting and the more complex the structure, the higher the mold temperature requirement.

5. What is the filling time? How to choose the filling time?

The time from the beginning of the molten metal to the filling of the cavity is called the filling time. The filling time of aluminum alloy die-casting is: 0.01S~0.1S. The principles for selecting the filling time are:

(1) When the alloy pouring temperature is high, the filling time should be longer;

(2) When the mold temperature is high, the filling time should be longer;

(3) When the thick wall part is far from the inner gate, the filling time should be longer;

(4) For alloys with high melting heat, the filling time should be longer;

(5) When the exhaust effect is poor, the filling time should be longer.

6. What is the holding time? What role does the holding pressure play? How to choose the holding time?

The holding time is also called the holding time. It is the time required for the molten metal to solidify under the action of the pressure ratio after filling the cavity. The function of the holding pressure is to make the solidified metal crystallize under pressure, so as to obtain a casting with a dense internal structure. The holding time of die-cast aluminum is 1 to 2 seconds when the wall thickness of the casting is less than 2.5MM, and 3 to 8 seconds when the wall thickness of the casting is 2.5 to 6MM. The selection principle is:

(1) The higher the crystallization temperature range of the die-casting alloy, the longer the holding time;

(2) The thicker the casting wall, the longer the holding time can be;

(3) If it is a top gate, the holding time can be longer, and the holding time for a thicker inner gate should be longer.

7. What is the retention time? How to choose the retention time?

The mold holding time, also known as the cold mold time, is the time the casting stays in the die. That is, the time required from the start of the pressure holding to the mold opening and the casting ejection. Sufficient mold holding time can ensure that the casting is fully solidified and cooled in the mold and has a certain strength. Usually, the shortest time for the casting to be ejected without deformation or cracking is appropriate. The mold holding time of die-cast aluminum alloy castings is 5S~30S, which is directly related to the wall thickness of the casting. The thicker the wall thickness of the casting, the longer the mold holding time.