Extrusion Pieces Common Defects

What are the common pitfalls of squeezing Extrusion pieces?

Cold extrusion often due to deformation process design is wrong, will make the blank in the extrusion process to produce a variety of defects. Therefore, only in advance to understand the causes of these defects in order to design the deformation process, take an effective solution to ensure the production of qualified extrusion.

First, the surface is folded

Extrusion pieces skin metal is pressed into the blank surface of the formation of defects, known as the surface of the fold. For example, in the positive extrusion, squeeze the head of the larger rod-shaped Extrusion pieces, the need to use two forming process. It is possible that the radius of the fillet in the second forming step is small because the radius of the workpiece in the first positive extrusion is too large or the corresponding cone angle is too small So that the material of the blank transition zone portion is pressed into the bottom plane of the end portion to form a folded sheet. Another example, when the bottom of the anti-extrusion with a large radius of the fillet radius, and the bottom of the blank for the right angle transition, in the extrusion process will produce folding, its formation process. If the extrusion deformation continues, this folding will also be moved to the side of the workpiece.

Second, the surface crease

Extrusion pieces In the process of deformation, the excess skin metal blocked and accumulated at its borders, with the deformation continues to deep into the material formed within a defect, is known as the surface crease. When the dead zone is squeezed, the skin of the latter part of the blank is slid into the die exit direction by the metal of the dead zone, and the excess skin metal is accumulated at the entrance of the dead zone. Subsequently, the excess skin is pulled into the interior of the metal along the slip surface and extends forward with the flow of the metal to form a crease. Sometimes, squeeze Extrusion pieces removed from the die, the dead zone metal quickly fall off, is caused by this defect.

Similarly, anti-extrusion and composite extrusion, but also because of its deformation of the dead zone metal to prevent the skin metal sliding and crease. Anti-squeeze when the bottom of the corner of the peeling off, the composite extrusion of the transverse crease.