Lightweight load-bearing heat dissipation multifunctional pomelo peel-inspired structures fabricated by laser powder bed fusion

Abstract

   The heat dissipation structure used in modern airborne radar chassis not only requires lightweight, but also pursues better mechanical properties and heat dissipation performance. In this study, a stochastically porous pomelo peel-inspired gradient structure was fabricated by laser powder bed fusion using Al-Mg-Sc-Zr powder. This study focused on the formability, microstructure, mechanical properties, and heat dissipation performance of the biomimetic structure through experimental and finite element analysis approaches. The influence of volume fraction (VF) on structural mechanical properties, deformation modes, stress distribution, and heat dissipation performance was investigated. The results showed that the mechanical properties of the structure declined as the VFs decreased. The optimal mechanical performance was obtained at the VF of 45%, where the compressive strength, specific energy absorption (Ws), and specific compressive strength values were measured to be 63.47 MPa, 34.84 J/g, and 142.16 MPa/(g·cm-3), respectively. Moreover, the Ws of the structures was higher than that of the reported aluminum alloy structures at the same VF. The biomimetic structure exhibited improved heat dissipation performance as the VFs decreased, with Reynolds number ranging from 2700 to 13,400. The structure of 30% VF with a remarkable heat transfer efficiency index of 1.86 displayed the best heat dissipation performance. In addition, compared with the traditional fin structures, the bionic structure possessed better thermal resistance, heat transfer efficiency index, and temperature uniformity at the same VF. This study demonstrated notable potential of pomelo peel-inspired design for lightweight load-bearing applications capable of heat-dissipating performance, providing a novel perspective for design and fabrication of versatile structures in the aviation field.