Aluminium ingots produced by smelting and casting of aluminum and aluminum alloys, usually used as ingredients for plastic processing. The inside of the ingot is coarse and uneven, and can be divided into a fine grain zone, a columnar crystal zone and a coarse equiaxed zone from the broken surface to the center. The ingot itself has very low strength and poor plasticity, and generally cannot meet the requirements of use. Therefore, in general, the ingot is subjected to processing deformation to change the shape and size of the section and improve its structure and performance. In order to obtain high-quality aluminum, the first ingot in the process of smelting and casting, chemical purification, melt purification, grain refinement, homogenization of structure and properties must be carried out to ensure the provision of high metallurgical quality ingredients.
There are many plastic deformation methods for aluminum and aluminum alloys, and the classification criteria are not uniform. At present, there are two most common classifications, one is to classify the workpiece according to the temperature characteristics of the processing, and the other is to classify the stress and strain state of the workpiece during the deformation process.
1. Classification according to temperature characteristics during processing
According to the temperature characteristics of the workpiece during processing, the pressure processing methods of aluminum and aluminum alloy can be divided into hot working, cold working and warm processing.
(1) Hot working Generalized hot working refers to plastic deformation of a metal box alloy in a wood temperature range in which work hardening does not occur. For aluminum and aluminum alloys, it refers to the plastic forming process performed by the ingot above the crystallization temperature. In hot working, the plasticity of the ingot is higher, and the deformation resistance is lower. It is possible to produce a product with a large deformation amount with a device with a small tonnage. In order to ensure the organization and performance of the product, the heating temperature, deformation temperature and speed of the workpiece, the degree of deformation, the temperature at the end of deformation, and the cooling rate after deformation should be strictly controlled.
(2) Cold working Generalized cold working refers to the plastic deformation of the metal box alloy at the temperature of work hardening. For aluminum and aluminum alloys, it refers to the plastic forming process performed at different temperatures of recovery and recrystallization. The process of cold working is essentially a combination of cold working and intermediate annealing. Cold working results in a finished product with a smooth surface, precise dimensions, good structural properties and the ability to meet different requirements.
(3) Warm processing is a plastic forming process between hot working and cold working. The warm processing of aluminum alloys is mostly a processing method used to reduce the deformation resistance of metals and improve the plasticity of metals.
2. Classification according to the force and deformation modes during the deformation process
The workpiece is classified into the force and deformation mode of the deformation process. The aluminum pressure processing can be divided into rolling, extrusion, forging, drawing, spinning, forming and Shenzhen processing. The pressure processing of aluminum is based on the force of the workpiece. Various forms of deformation.
Among the aluminum and aluminum alloy processed materials, the most widely used and widely used rolls of sheet metal, strip, strip, foil and extruded pipe, bar profile and wire are used. According to the statistics of the past year, the annual output of these two types of materials accounts for 58% and 39% of the world's total annual aluminum production. The remaining aluminum and aluminum alloy processed materials, such as forged products, only stand for the total output of aluminum. A few points.
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