Forming mechanism of three-dimensional integral fin based on flat surface

XIANG Jian-hua(向建化)^{1, 2}, DUAN Ji-an(段吉安)¹, ZHOU Hai-bo(周海波)¹, ZHANG Chun-liang(张春良)², LIU Gui-yun(刘贵云)², ZHOU Chao(周超)²

(1. College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
2. School of Mechanical and Electric Engineering, Guangzhou University, Guangzhou 510006, China)

Abstract:To improve heat-transfer performance, a novel integral three-dimensional fin-structure on the plat surface was presented to increase the evaporation efficiency. The three-dimensional fin-structure is composed of a spiral micro-groove and multi radial micro-grooves. Both ploughing-extrusion (P-E) and stamping were used to form the integral-fins with a connection between radial and circumferential directions. Based on the SEM results, the relationships among P-E speed v_P-E, rotational speed n_p and feed f_p, and among interference length L_i, stamping feed angle θ_c and stamping depth a_c were analyzed. The effects of processing parameters on the groove morphology and the matching relationship between parameters were also discussed. The integral finned surface with micro-grooves and cracks can be obtained under such processing conditions: P-E depth a_p=0.3 mm, a_c=0.3 mm, the interval of helical groove d_p=1.24 mm, θ_c=2° and n_p=50 r/min.

Key words:three-dimensional integral fin; ploughing-extrusion; stamping; micro groove; enhanced boiling