Compaction of machining chips: Experiments and modeling

Abstract

The process of compaction of machining chips inside a cylindrical process chamber is investigated. The compaction process can be either an independent process or the first step in the Friction Extrusion Process (FEP) in which consolidated chips are softened due to frictional heating and are turned into a wire through an extrusion hole in the die. The current study focuses on gaining an understanding of the compaction process through experimental investigation and numerical modeling. In order to understand the characteristics and material behavior of the chip material during the compaction process, discontinuous machining chips of aluminum alloy 6061 with one of several chip lengths were used in the study. A non-rotating solid die without a central extrusion hole was used to compress the chips to produce a disk. The chips as a whole were considered as a porous continuous material with a certain starting density that will change during compaction. The dependence of elastic and elastic-plastic properties of the porous material on the changing density was investigated and a mathematical model for the elastic-plastic behavior was developed.