Forming Process and Mechanism of Microcapillary Grooves of Miniature Cylindrical Heat Pipe

Abstract

Miniature heat pipe is one of promising means of removing high heat flux for electronics cooling in limited available space. How to produce narrow and deep microcapillary grooves is the critical issue in promoting performance of axially grooved miniature heat pipe. In this work, the microcapillary grooves for miniature cylindrical heat pipe was fabricated by using oil-filled high speed spinning method. The forming process of microcapillary grooves was investigated. The influence of technical parameters on characteristics of microcapillary grooves was analyzed and the optimal technical parameters were found out. The experimental results show that drawing speed ranging from 48cm/min to 64cm/min, spinning ball number of 4 and big distance between the end of multi-tooth mandrel and the center of spinning balls within 3.7 mm should be chosen to obtain narrow and deep microcapillary grooves. In addition, the forming mechanism was investigated by observing microstructure of cross-section of microcapillary grooved tubes.