Abstract:

A kind of third-generation enhanced heat-transfer component,namely 3D integral fin,was machined by the rolling-ploughing-extrusion composite machining,and the corresponding formation characteristics,machining conditions and formation mechanism were analyzed.Experimental results show that,at a rolling depth and a plou-ghing-extrusion（P-E） depth of both 0.20mm,a rotational speed of 50r/min and a feed rate of 0.16mm/r,optimal 3D fins with the height of 0.25mm can be machined on the outer wall of the red copper tube which is 16 mm in diameter and 1.5 mm in wall thickness. Analytical results indicate that there is a matching relationship not only between the rolling depth and the rotational speed but also between the feed rate and the P-E depth, that two different fin structures can be obtained in different machining conditions. One is the composition of V-shaped and U-shaped grooves, and the other is of only V-shaped grooves, and that 3D integral fins can be machined by the rolling-ploughing-extrusion composite machining when single V-shaped grooves are formed by both rolling and P-E processing.

Key words: outside fin tube, rolling, ploughing-extrusion, enhanced heat transfer, functional structure