2017 Volume 58 Issue 674 Pages 229-231
A new extrusion system for producing tubes with greatly twisted fins was proposed. In the proposed extrusion system, the metal flow was controlled by rotating a mandrel and a flow guide during extrusion to produce fins with various twisted shapes. The characteristics of the twist for fins were investigated by carrying out extrusion tests for a variety of rotation speeds and rotary directions of the mandrel and the flow guide. The specific angle of twist of the fin was increased by increasing the rotation speed of the mandrel and the flow guide. A tube with greatly twisted fins was obtained by rotating the mandrel and the flow guide in the same direction.