Isothermal extrusion die and extrusion method thereof

Abstract

The isothermal extrusion die comprises an extrusion cylinder, a flow guide cylinder and a forming cylinder which are axially arranged from left to right, the cross sectional areas are sequentially reduced, the extrusion cylinder and the flow guide cylinder are in butt joint communication through a first-stage deformation cylinder, and the flow guide cylinder and the forming cylinder are in butt joint communication through a second-stage deformation cylinder. The extrusion cylinder, the flow guide cylinder and the forming cylinder are equal in cross sectional area and same in shape on the two sides, the cross sectional area of the first-stage deformation cylinder and the cross sectional area of the second-stage deformation cylinder are gradually decreased from left to right, cooling pipes are wound outside the flow guide cylinder, the forming cylinder, the first-stage deformation cylinder and the second-stage deformation cylinder, and a temperature sensing controller is further arranged in the mold. The conditions of stress concentration and temperature rising and falling in the extrusion process can be effectively dispersed, the extrusion temperature change of the die and the bar in the cavity is detected in the whole process, the whole extrusion process is conducted in a constant-temperature state, the temperatures of the inner layer and the outer layer of the discharged material and the front section and the tail section of the extruded bar are balanced and uniform, and the output rate is high. Deformation of the die caused by high temperature, high pressure and high friction is effectively prevented, and the service life of the die is prolonged.

Description

technical field [0001] The invention relates to the field of alloy processing, in particular to an isothermal extrusion die and an extrusion method thereof. Background technique [0002] At present, there is still a big gap between China's aluminum alloy hot deformation extrusion process and foreign developed countries. Many aluminum extrusion production hopes to adopt new low-temperature rapid extrusion technology. Usually, the extrusion speed of solid profiles is 15m / min-50m / min. Between 10m / min-35m / min for hollow profiles, rapid extrusion means that the extruded product flows out of the die hole at a speed of more than 60m / min, due to the uneven flow of metal during extrusion (in the absence of lubrication It is especially serious when extruding), the bar itself has a certain temperature, and a lot of energy is generated during the extrusion production process, which leads to the continuous increase of the mold temperature, the bar is easily over-burned, and the discharge...

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Problems solved by technology

[0005] The bar is usually heated by induction furnace and electric heating wire furnace before extrusion. The induction furnace conducts induction heating on the bar. The advantage is fast heating, which is suitable for fast-paced production, but the disadvantage is also obvious. The internal and external heating will be caused by time and other reasons. The temperature of the inner and outer layers of the bar is not uniform, and the advantage of using an electric heating wire furnace is that the temperature of the inner and outer layers of the heated bar is more uniform, but the heating time is longer and the efficiency is lower.

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