Aluminum Alloy Profiles Of Rough Surface, Causes The Defects And Solutions Of Pits
The reason Aluminum Alloy profile surface roughness and pits defects:
(1): Die Aluminum Alloy work with hardness is not enough or not (normal hardness nitride 48 degrees 52 degrees above the mold work) or work with rough not smooth and sticky aluminum, die design with long increased friction, extrusion die for aluminum heating (time limit does not exceed 8 hours long) led with surface annealing work, the long time use of the original work is bellmouthing with parallel continuous extrusion die, the pellets with adhesive material surface. Often with aluminum extrusion, the working belt can not be repaired.
(two): Aluminum Alloy (high temperature extrusion tube, rod, three die temperature) increased deformation heat rise (20~60 degrees), thereby increasing the friction with the aluminum tube wall and work with the increase of aluminum with other metals (iron) viscosity, die with adhesive and aluminum metal particles more aluminum, surface roughness, pits is more serious. Extrusion speed (performance profiles in the head end of tail side section) to increase the flow rate of metal lead to increased thermal deformation and die (die dead zone around the work area of aluminum deposit, poor liquidity, more for the aluminum rod surface of aluminum, magnesium and silicon impurities and Mg2Si hard crystalline particles) increases, attached to the impurity profile surfaces become more dead.
Aluminum Alloy profile of rough surfaces, pock produced solutions:
(1): extrusion speed reasonable standard (using the profile surface roughness, extrusion speed pits when multiplied by 0.8 times the reasonable extrusion speed)
(two): appropriate extrusion of three temperature (with the pressure at the beginning of the pressure 210kg/cm2 no car, extrusion pressure at about 170kg/cm2)
(three): the design and manufacture of qualified moulds (the key is the strength of the die working belt and the length of the working belt)