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Die-casting Molds With Long Service Life

Edit: Smart Mold Technology Limited    Date: Aug 24, 2017

The use of die-casting mold features

In the die-casting process, the die forming mold parts forming conditions are extremely bad, they are subject to mechanical abrasion, chemical erosion and thermal fatigue of the repeated role.

1, metal liquid in the high pressure, high speed into the mold cavity, Die Casting Mold the mold cavity surface of the intense friction and impact, so that the mold surface erosion and wear.

2, the molten metal in the casting process will inevitably have slag into the slag on the surface of the forming parts of the complex chemical effect, Die Casting Mold aluminum and iron compounds like wedge, accelerated the formation and development of die casting mold cracks.

3, thermal stress is the main cause of cracks in the mold forming parts. In each of the die casting production process, the surface of the forming part of the metal in addition to the high-speed, high-pressure erosion, there is the absorption of metal in the solidification process of heat released, resulting in heat exchange. In addition, due to the relationship between the thermal conductivity of the mold material, Die Casting Mold the surface temperature of the forming part rises sharply, resulting in a large temperature difference with the inside, resulting in internal stress. When the metal liquid filling cavity, the cavity surface layer first to achieve high temperature and expansion, while the inner mold temperature is low, the relative expansion of small, so that the surface pressure. After the mold, Die Casting Mold the cavity surface and air contact, by the compressed air and paint the cooling and produce tensile stress. This alternating stress increases with the continuation of production, and when the fatigue limit of the mold material is exceeded, Die Casting Mold the mold surface layer is plastically deformed to produce cracks.

In order to maintain the durability of the profile, it is required that the profile has the characteristics of thermal fatigue resistance, wear resistance, non-stick mold and easy release. Therefore, the 4Cr5MoSiV1 (H13) material is used for the forming parts.

Second, the alloy melt temperature

Die casting mold production process, in order to better fill all die-casting mold holes and deep, to ensure that the metal flow when they melt each other, the use of die-casting mold, Die Casting Mold the metal should be the right choice of pouring temperature. Alloy casting liquid pouring temperature is as follows:

Material Name: Die Casting Liquid Temperature / ℃

(1) Zinc alloy: 420-500 ° C;

(2) aluminum alloy: 620-690 ° C;

(3) magnesium alloy: 700-740 ° C;

(4) copper-zinc alloy: 850-960 ° C.

Die-casting alloy temperature selection principle:

1. The lower the temperature of the metal pouring, Die Casting Mold the longer the life of the die-casting mold;

2. The use of low-temperature die-casting, it is possible to reduce the depth of the exhaust slot to reduce the risk of metal spilled;

3. The use of low temperature die-casting, can reduce the pressure chamber and the mandrel of the opportunity;

4. The use of low-temperature die-casting, Die Casting Mold casting can reduce the shrink holes and cracks in the production.

In short, the conditions permitting the case, die-casting alloy temperature, Die Casting Mold or the choice of low-temperature die-casting good.

Third, the mold work temperature

Die-casting mold operating temperature according to its die-casting alloy and different, the following are the recommended value of several alloy mold, for use:

Mold Name: Operating Temperature / ℃

(1) Zinc alloy die: 150-180 ° C;

(2) aluminum alloy mold: 180-225 ℃;

(3) magnesium alloy mold: 200-250 ℃;

(4) copper and zinc alloy die: 300 ℃.

Die-casting mold operating temperature selection principle:

1. Mold temperature is too low, the internal structure of the loose casting, air discharge difficult, difficult to shape;

2. Mold temperature is too high, the casting internal structure is dense, Die Casting Mold but the casting easy to "welding" attached to the mold cavity, stick mold, easy to unload the casting, at the same time, too high temperature will make the body itself expansion, affecting the casting size accuracy;

3. Mold temperature should be selected in the appropriate range, the general test after the appropriate temperature control as well.

Die-casting mold lubrication

1. The purpose of lubrication

Lubrication as a die-casting molds and die-casting parts of the agent, Die Casting Mold easy to die-casting mold unloading; as die-casting mold and press the active part of the lubricant, reduce friction and improve the life of die-casting mold; In addition, Agents, Die Casting Mold and reduce the die due to long-term work of thermal fatigue, extending the die life.

2. Lubricant requirements

For the selection of lubricants, should meet the following needs:

(1) can not make the die casting in the cavity adhesion;

(2) can not corrode the mold surface of the steel;

(3) can not produce toxic gases;

(4) can not produce ash when heated;

(5) after lubrication, should be evenly attached to the cavity and the work surface, not washed away by high-pressure metal.

Die-casting mold with the temperature changes, the product quality conditions play a significant impact factors, so theoretically, standardized operation, Die Casting Mold the characteristics of die-casting molds are required to die with our mold temperature to maintain a certain temperature range Inside. According to the different types of alloys, the product structure of the different set of the corresponding mold temperature For the alloy type, the die casting mold, especially magnesium alloy, zinc alloy parts need to be equipped with mold temperature machine; for the product structure, the die casting mold With pictures, thin-walled parts, complex parts need to be equipped with mold temperature machine.

Smart Mold Technology Limited