The purpose of die-casting mold temperature control
Die-casting mold, before use, need to preheat to a certain temperature; die-casting mold temperature control purpose, on the one hand, is to avoid high-temperature metal liquid to cold die-casting mold “thermal shock”; on the other hand, die-casting mold temperature control is to avoid the metal liquid “cold” and caused by pouring insufficient, cold compartment, ” freezing” and other defects.
In continuous production, die-casting mold temperature to live up, especially die-casting containing copper and magnesium-aluminium alloy, magnesium alloy and copper alloy and other high melting point alloys, the temperature rises quickly. The high temperature will make the liquid metal produce a sticky mold, but also make the casting cool slowly, resulting in coarse grain. Therefore, if the die-casting mold temperature is too high, effective cooling measures should be taken.
What are the principles and methods of temperature control of aluminium die-casting Mold?
What are the principles and methods of temperature control of aluminium die casting die? In the production process of aluminium alloy die casting, the temperature is one of the core process elements, die casting die temperature control directly affects product quality and production efficiency; the choice of die casting die temperature control method is especially important; V1 combined with the actual situation of aluminium alloy die casting, analysis of aluminium alloy die casting die temperature control methods to achieve mold thermal balance and solve the problem of thermal joints.
The successful development of the automobile industry brings more opportunities and new challenges to the die-casting industry. In die-casting production, die temperature influences casting quality, die life and production cycle. Therefore, mold temperature control has become an indispensable process method in modern die-casting technology. Yu Huasheng Hardware on dies casting die temperature importance, principles, control methods to explain, as well as for the control method selected a set of die casting dies temperature control methods for a brief analysis:
The importance of die-casting die temperature and control principles
Die casting mold is the molding process equipment in the casting production process. The stability of the temperature field distribution established in the die has an important impact on the quality of the casting, production efficiency and die life and is directly related to the cost and economic efficiency of the casting production. The temperature field within the mold must be within the range required by the process to obtain castings with qualified appearance and internal quality. On the contrary, too high a temperature will form strains, bubbles and other defects, prolong the cooling time and reduce production efficiency, producing cold compartments, under-pouring, porosity and other defects. Die-casting molds are produced under high temperature and high-pressure environments for a long time. If coupled with the unstable temperature field of the die and long-term cyclical thermal expansion and contraction, the die is more likely to fail, greatly shortening the service life and reducing production efficiency.
Die casting mold temperature control principle.
During the casting process, the heat exchange between the crystallizer and the metal liquid reaches an ideal thermal balance, i.e. the crystallizer absorbs and discharges equal amounts of heat to achieve dynamic thermal equilibrium. Spot cooling is carried out on-site to promote the formation of thermal equilibrium.
(1) Generating part: The casting structure has the highest temperature during the die-casting process and is prone to the formation of shrinkage holes, shrinkage loosening and stress concentration during the cooling process.
(2)Control mode – point cooler
To achieve the purpose of water saving, the point cooler adopts the way of water recycling, and to ensure adequate pressure, the collection and distribution box is added.
(3) Casting hot joints at the core plus high-pressure point cooling
(4) point cold water treatment: point cold water in the cooling pipeline will encounter sudden cold and sudden heat, pipeline thinning, etc., the old-style water treatment is generally used to soften the treatment, but the production often can not meet the water quality requirements, point cold tube blockage frequently, resulting in huge human, material and financial losses, the general use of RO reverse osmosis water treatment device, the point cold water for processing into pure water.
The thermal balance
(1) Principle: In the production process of aluminium alloy die-casting mold, the heat absorbed by the mold and the heat emitted should be consistent to avoid the mold getting colder or hotter, reduce shrinkage, shrinkage, shrinkage, etc. . The uneven temperature of the mold causes; casting defects such as porosity, improve the appearance and inner quality of the casting, and improve the mold life and production efficiency. The process of achieving thermal balance is to cool the mold at a high temperature and heat it at a low temperature.
(2) Control mode – die casting mold temperature machine
Mold temperature machine is divided into water type and oil type, control temperature in 160 ℃ about 160 ℃ and the environment requirements of the higher general choice of water type, higher than 160 ℃ available choices of oil type. Mold temperature machine is generally the main function of playing the hard mold parts; the temperature regulation and control of the die-casting production process are not enough.
(3) control mode – mold cooling unit
Mold cooling unit is used with mold cooling circulating water to cool the high-temperature part of mold to keep the heat balance of mold cavity temperature.
Die-casting mold temperature monitoring methods
(1)Handheld thermal imaging camera
Thermal imaging test every shift and adjust the mold according to the temperature.
(2)Thermocouple or thermal camera temperature monitoring system.
According to the mold, the thermocouple is embedded in the mold (or a thermal imaging camera is placed on the left and right side of the mold), and the temperature distribution of the mold is monitored in real time through the control system. The mold temperature is adjusted by analyzing the monitoring data. Temperature monitoring.
Mold temperature is one of the very important process parameters, which not only determines the quality of the casting but also seriously affects the service life of the mold and production efficiency. Therefore, try to use an automatic temperature control system to ensure that the parameters are controllable. Aluminium die-casting mold temperature control combines various methods; one can not think that only one temperature control method can control the mould temperature; it should be based on the different conditions of the die-casting production process and die-casting molds, using different temperature control methods.
With the development of aluminium alloy die-casting mold technology, new temperature control methods are constantly updated; the use of new methods can further enhance the mould temperature control level and contribute to the production of faster and better die-castings.