Influence of extrusion temperature on industrial aluminum profiles
The extrusion temperature of industrial aluminum profiles has a very important influence on the deformation process of aluminum alloy, the microstructure and properties after deformation, especially the microstructure and properties after subsequent heat treatment.
Industrial aluminum extrusion is affected by temperature:
If the temperature in the process of extrusion of industrial aluminum profiles is too low, the deformation resistance will be too large, which is easy to cause stuffy car, and the deformation is difficult to carry out. When extruding high magnesium alloy, duralumin and super duralumin, when the proportion of equipment is small and the extrusion coefficient of aluminum profile is large, the probability of stuffy car is high. If the heating temperature is too high in the extrusion process of industrial aluminum profiles, the deformation resistance is reduced, and the car will not be stuffy, but it must be extruded at low speed. This problem seems simple, but in the actual industrial aluminum extrusion production process, due to the heating temperature and extrusion, mold temperature control is often not in place, or high or low, the resulting stuffy car phenomenon and extrusion cracks always occur;
Therefore, extrusion of hard aluminum alloy profiles, especially extrusion of high magnesium alloy, if the equipment capacity is insufficient, it is best to squeeze one or two soft alloys before production, to improve the temperature of the work and mold, and then enter the normal extrusion production process, which can significantly reduce the occurrence of stuffy car phenomenon, some enterprises call this “traction extrusion”, if the industrial aluminum profile extrusion temperature is high, extrusion speed is fast, Cracks may occur immediately; At present, in the extrusion production of hard aluminum alloy, the proportion of cracked waste products is basically always in the first position, for soft aluminum alloy, the temperature has no great impact on the extrusion process of aluminum profiles.
The organizational properties of industrial aluminum products are affected by temperature
High extrusion temperature of industrial aluminum profiles, for some aluminum alloys, such as 6061, 6063 and other soft aluminum alloys (these aluminum alloys have a higher melting point, and the normal extrusion temperature is much lower than the melting point temperature), there will be coarse grains, its tensile strength, yield strength, hardness, and elongation; In particular, some aluminum alloys have recrystallized or partially crystallized during high temperature extrusion, and the crystalline grains will rapidly grow into coarse grain structures and reduce mechanical properties during subsequent heat treatment. For some aluminum alloy profiles, such as 2 series and 7 series aluminum alloys, after extrusion processing, most of them must be quenched to improve the mechanical properties of industrial aluminum profiles.
High temperature extrusion of industrial aluminum profiles can reduce the coarse crystal structure and improve the mechanical properties. However, low temperature extrusion will aggravate the formation of coarse crystal ring and eventually lead to the deterioration of mechanical properties of aluminum profiles.
The influence of extrusion temperature on surface quality of industrial aluminum profiles:
The industrial aluminum extrusion products in cold state have accurate dimensions and good surface finish; As the extrusion temperature of industrial aluminum profiles rises, the surface finish deteriorates as a whole. For the same aluminum profile products, the front section temperature is lower than the back end, the front end surface quality is significantly better than the back end, when the temperature is too high, it is easy to produce pitting or pitting.
