In the extrusion production of aluminum profiles, the common defects are more intuitive, such as bending, twisting, deformation, slag inclusion and so on. The defects of "adsorbed particles" are difficult to find without careful observation or hand touch. Its harm is: in the production process of electrophoresis and spray profiles, it is difficult to remove, affecting the surface beauty of profiles, resulting in waste products.
The main reasons for the formation of "adsorption particles" are as follows:
1 Influence of mold
In extrusion production, the mold is working under high temperature and high pressure, which will produce elastic deformation. The die work belt begins to be parallel to the extrusion direction, and under pressure, the work belt deforms into a trumpet shape, and only the cutting edge part of the work belt contacts the aluminum adhesive formed by the profile, which is similar to the tool chip tumor of the turning tool. In the formation process of aluminum bonding, particles are constantly brought out by the profile and adhered to the surface of the profile, resulting in "adsorbed particles".
2 Influence of extrusion process
The correct selection of extrusion process parameters is also an important factor affecting "adsorbed particles". The extrusion temperature is too high, the extrusion speed is too fast, the more "adsorbed particles", the reason is that due to high temperature, fast speed, the profile flow speed increases, the degree of mold deformation increases, the flow of metal is accelerated, the deformation resistance of metal is relatively weakened, and it is easier to form aluminum adhesion phenomenon.
3 Influence of casting rod quality
The quality of casting rod is an important factor affecting the surface and extrusion forming of aluminum profiles. The formation of adsorbed particles is closely related to the quality of casting rods. The common defects of the casting rod are slag inclusion, loose, coarse grain, segregation, bright grain, etc. All these casting rod defects have one thing in common, that is, they are not well welded with the casting rod matrix, resulting in the discontinuity of the matrix flow, which is an important factor in the formation of "adsorbed particles".
The influence factors of "adsorption particles" are mainly three aspects of the mold, casting rod, extrusion process, the operation level of the operator is also reflected in these three elements, on the basis of production practice, constantly analyze the problem, sum up experience, you can reduce or avoid "adsorption particles", greatly improve the yield and production efficiency of profiles.