What is the reason for the surface damage of aluminum alloy shell? How to solve it?

Cause of damage

1. Impurities or ingot composition segregation are attached to the ingot surface (the phenomenon of uneven distribution of constituent elements in the alloy during crystallization is called segregation.)

When there are a large number of segregation floating objects on the ingot surface and the ingot is not homogenized or the homogenization treatment effect is not good;

There are a certain number of hard metal particles in the ingot, when the metal flows through the working belt during extrusion;These segregation floats or hard metal particles adhere to the surface of the working belt or cause damage to the working belt and scratch the surface of the profile.

2. There are bare metal or hard inclusions in the graphite strip on the discharge track or swing bed, which will scratch the surface of the profile when it comes into contact with the profile.

3. There are sundries on the die cavity or working belt, and the hardness of the die working belt is low, so that the surface of the working belt is injured during extrusion and the profile is scratched.

Solution

1. Strengthen the control of ingot quality;

2. Improve the quality of mold repair, regularly nitride the mold and strictly implement the nitriding process

3. Handle with care during production, and try to avoid dragging or turning the profile at will

4. Use soft felt to isolate the profile from the auxiliary equipment to minimize the contact damage between the profile and the auxiliary equipment.