The 27th and final article in this Extrusion Defects series summarizes the root cause analysis of some common conditions visible on the as-extruded surface in the extrusion of 6000 series alloys. As covered in the previous publications since August 2014, the visual appearance of the extruded surface as well as those conditions that are not visible to the naked eye are an important feature of products for service in many applications, such as architectural, transportation, and window and door trim. Too often, the only means of avoidance is to decrease extrusion speed, reduce lot size, and increase scrap allowances, which hinders press productivity-although the loss in throughput due to these action is ill defined.
展开▼
