关键词: 整体外翅片, 刀具, 单刃, 圆锥面, 翅片形貌, 强化传热

Abstract:

3D integral outside finned tubes were fabricated by using a tool with single edge and cone extruding face,and the forming process of fins as well as its dependence on the radius of cone extruding face was investigated. Then,the forming mechanism of fin micromorphology and the influences of cutting parameters on fin micromorphology were analyzed. It is found that,in the forming process,the surface metal material of workpiece only splits
rather than removes from the workpiece body,and the split chips are extruded into fins by the cone extruding face. The forming process of fins can be divided into three stages including splitting,sliding and fins forming,and big radius of cone extruding face contributes to the forming. Moreover,it is indicated that the microcrack to intersect the whole fin at the top makes the fin turn into double fins microscopically,and that the thickness of fins increases with the cutting depth and the pitch of fins increases with the feed.

Key words: integral outside fin, tool, single edge, cone extruding face, fin morphology, enhanced heat transfer