High quality aluminum ingot production billet should not have significant loose, porosity, and low content of hydrogen and oxidation inclusion, fine grain. In order to optimize the distribution of diffusion phase particles after alloy averaging, a two-stage averaging process of low temperature and then high temperature can be adopted. After double-stage averaging, the dispersion particles in the alloy are more evenly distributed and fine. The high strength aluminum alloy has a wide crystallization range and a larger tendency of eutectic cracking during non-equilibrium solidification.
Melt electromagnetic stirring technology is to produce electromagnetic force in the aluminum molten pool, stir the activity of aluminum melt in the molten pool, make the melt composition average, avoid the pollution of iron tools during manual stirring. Hydraulic semi-continuous forging machine is used for forging, which has the characteristics of stable operation, high degree of automation and high control accuracy. The ultimate function of aviation aluminum ingot is closely related to its structure.
Therefore, no crack large ingot forging is a large specification of material production need to solve the hub setback. Because cast ingot dimension is big, the heat stress of contraction is big, EASY craze. In order to forge large crack free ingot with high quality, a series of melting and casting technologies have been developed. Melt electromagnetic stirring is one of the most important new technologies. Because of the high content of main elements in the alloy, high strength aluminum alloy is easy to produce segregation in the melt, difficult to distribute evenly, and the nucleation rate is reduced, the grain size is coarse. At the same time, the ingot billet was tested by ultrasonic flaw detection for inclusions, cracks, pores and other defects. In addition to the hydrogen content, some alkali metals Li, Na, K and alkaline earth metals Ca should also be strictly controlled.
Large wide thickness ingot is easy to crack during forging. The stable control of forging process is very important to the forming of aluminum ingot. The average treatment can make the alloy composition evenly distributed, eliminate the non-equilibrium crystallization low melting point phase, spheroidize the hard second phase, form a coherent dispersion phase for subsequent processing to control the grain structure of the material, reduce the quenching sensitivity of the alloy, improve the strength and toughness of the material for tissue preparation.
Post time: Aug-17-2022