M Moodi - MSc Student
A. H Jalali Aghchai - Assistant Professor, Iran University of Mines and industries, Kamraniye, Terhran, Iran

Double layer metal tubes have extensively been gaining interest for application within different industries including aerospace, oil, and manufacturing various exchangers. One of common proves to form these tubes is bending within which the spring back is the main problem. In this paper, this spring back was studied within double layer brass- stainless steel made and one layer ones both 304. Then features of new tube were compared to one layer tubes. Finally theoretical relations pertained to double layer tubes bending process were inferred. After that, in order to validate theoretical relations, results derived from it were compared to experimental results. The investigation for effects of significant parameters of radius and bending angle came last.

die bending, CNC tube bending, double layer tube, spring back, mandrel, wiper