On chopping–extrusion of integral-fin copper tubes

A new method for machining integral-fin tubes (IFT) is presented, namely chopping–extrusion. Experimental observation reveals that the process of forming fins can be divided into three stages, i.e. chopping–extrusion–forming. Experimental results show that there are four factors, cutting tool geometry, extrusion depth, feed and speed of chopping–extrusion, playing dominant roles in the process of fin forming. For a certain cutting tool with given chopping–extrusion speed, the fin height increases with increase of the extrusion depth and feed. A continuous process of fin forming and the optimal fin shape can be obtained only if proper parameters are given. Production costs are reduced and productivity increased by employing this machining method on a commercial lathe because of its easy performance and the simple forming of the fins.