In the process of producing aluminum alloy castings, due to improper operation, improper selection of materials, etc., a variety of quality problems may occur in aluminum alloy die castings, including net burrs. What is going on?
The network burrs appearing in aluminum alloy castings include network traces, network patterns, and crack burrs. The main manifestations are the network-like raised marks and metal thorns formed on the surface of the die casting. The occurrence of net burrs in aluminum alloy die castings may be due to the excessively fast metal flow rate and flushing of the front wall; it may be that the surface roughness Ra of the mold cavity is too large; it may be that the temperature difference between the hot and cold temperatures of the mold is too large; Process errors; it may be that the pouring temperature of the alloy liquid is too high and the mold is not warmed up enough; it may be caused by cracks on the surface of the mold cavity; the heat conduction is concentrated near the gate area; the friction resistance is large; and the erosion by the hot-melt metal is strong , Cold and heat altered violently, generating enthusiasm and forming cracks.
Now that we have found the cause of the net burr on the aluminum alloy die castings, the next step is the solution. Workers need to correctly design the pouring system to meet the premise of good forming, and use a small injection speed as much as possible; improve the surface quality of the mold cavity and reduce the value of Ra; try to reduce the pouring temperature of the alloy liquid; fully predict the mold before casting Heat to make it reach the working temperature range; correct selection of mold materials and reasonable heat treatment process; regular annealing of the inserts to eliminate stress.
