Finite-Elements Modeling and Simulation of Electrically-Assisted Rotary-Draw Bending Process for 6063 Aluminum Alloy Micro-Tube

Xinwei Wang,Yanhu Zhang,Minghan Ding,Zhenlong Wang,Jie Xu,Bin Guo,Debin Shan

doi:10.3390/met11121956

Xinwei Wang, Yanhu Zhang + Show 5 more

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https://doi.org/10.3390/met11121956

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Abstract

Bent micro-tubes have been frequently applied in electronics, medical devices and aerospace for heat transfer due to the increasing heat flux in high-density electric packages. Rotary-draw bending (RDB) is a commonly used process in forming tubes due to its versatility. However, the control of forming defects is the key problem in micro-tube bending in terms of wall thinning, cross-sectional deformation and wrinkling. In this paper, a three-dimensional (3D) finite-elements (FE) modeling of electrically-assisted (EA) RDB of 6063 aluminum alloy micro-tubes is developed with the implicit method in ABAQUS. The multi-field coupled behavior was simulated and analyzed during the EA RDB of micro-tubes. Several process parameters such as micro-tube diameter, bending radius, current density and electrical load path were selected to study their effects on the bending defects of the Al6063 micro-tubes. The simulated results showed that the cross-sectional distortion could be improved when electrical current mainly pass through the vicinity of the tangent point in the micro-tube RDB, and the cross-sectional distortion tended to decrease with the increases of current density and tube diameter, and the decreases of bending speed and radius. A trade-off should be made between the benefit and side effect due to electrical current since the risk of wall thinning and wrinkling may increase.

Highlights

With the miniaturization of electronics, medical devices and micro-satellites, more and more high-performance electronical systems such as high-resolution CCD have been integrated into increasingly small spaces [1,2]
We first analyze the distribution and evolution behavior of electrical, thermal and stress-strain fields during EA Rotary-draw bending (RDB) of micro-tubes based on the simulation results under die-to-die configuration
Considering the beneficial effects caused by the so-called electroplasticity [18], it is rational to believe that the EA RDB has the advantages

Summary

Introduction

With the miniaturization of electronics, medical devices and micro-satellites, more and more high-performance electronical systems such as high-resolution CCD have been integrated into increasingly small spaces [1,2]. The heat flux density soars and the non-uniform temperature distribution in the devices is enhanced, causing the premature failure of the electronical systems [3]. This extreme thermal condition cannot be addressed by solely traditional thermal management technique. Similar to traditional tube bending, micro-tube bending is a typical nonlinear process affected by various parameters and the so-called size effects, exhibiting multiple defects such as wrinkling, overthinning, cross-section distortion and springback [7] These forming defects undoubtedly weaken the thermal exchanging ability of the heat pipe or even make it disappear

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