1. Heat treatment process of aluminum alloy.
The aim of this process is to obtain a more homogeneous solid solution by maintaining a sufficient period of time between 535 and 550 degrees for a solid melt to be formed from a large amount of usable hardening elements, such as copper, magnesium, zinc, or multi-dissolved solids, for 6 to 8 hours. 1. Aluminum alloy solid solution temperature, aluminum alloy wheel solid solution point 530 degrees, melting point 555 degrees, above this temperature began to melt into aluminum melt.
Main points of aluminum alloy heat treatment process:
A. When the temperature rises, the cooling water of the windmill is first turned on smoothly, then the operating temperature of the windmill is set and the combustion condition is set.
When casting, place A on the top of the casting, and prohibit A from facing down (solid solution).
B. solid solution aging treatment conditions 545 degrees *8H+130 degrees *6H temperature must be stable and uniform temperature, according to the rim design strength,
Material, characteristics and testing decisions.
C. quenching temperature is 60 degrees --80 degree water temperature, castings are not easy to deform, water quenching time is calculated from the door.
The top part of the casting is completely foam to water, and the time is 16 seconds ---20 seconds to finish the instant quenching water.
D. Complete inspection items after solution treatment, deformation inspection, shaping, typing to prevent abnormal quality tracking, after aging
The hardness of a casting is measured at the upper and lower levels of the trolley, with a value of 65-75HB. Cooperate with continuous automatic operation and high-temperature operation, after pre-discharging and then into the furnace, according to the timer set by the timing of operation in and out of the furnace.
2. The quenching process of aluminum alloy.
When quenching water, the casting is taken out from the solid solution temperature in the furnace and the quenching time is delayed. The optimum quenching time is 15 seconds > 18 seconds. The most common quenching solution is water, the rest is air or liquid nitrogen, but the stress and distortion caused by quenching should be considered. Sometimes hot water should be used to prevent deformation and fracture. 5. When the precipitation hardening heat treatable aluminum alloy is quenched to normal temperature, because the solubility of the solute is low at low temperature, the saturated instability state occurs, so some microstructure will precipitate in the base, and the precipitation effect in the room temperature is natural aging, if the precipitation needs to be heated at a certain temperature, it is artificial aging.