Thermal conductivity prediction of closed-cell aluminum alloy considering micropore effect

Abstract

Large quantities of micro-scale pores are observed in the matrix of closed-cell aluminum alloy by scanning electron microscope, which indicates the dual-scale pore characteristics. Corresponding to this kind of special structural morphology, a new kind of dual-scale method is proposed to estimate its effective thermal conductivity. Comparing with the experimental results, the article puts forward the view that the prediction accuracy can be improved by the dual-scale method greatly. Different empirical formulas are also investigated in detail. It provides a new method for thermal properties estimation and makes preparation for more suitable empirical formula for closed-cell aluminum alloy.

On the effective thermal conductivity of aluminum metal foams: Review and improvement of the available empirical and analytical models

“…The corrected version of the model of Boomsma and Poulikakos [8], Eq. (57), and the improvement suggested by Dai et al [48], Eq. (58), can not be applied without violating the geometric constraint.…”

“…The revised model is reported in Eq. (57). In addition, in [48] the contribution of the ligament orientation in layer C is even considered, which allows to overcome the restricting hypothesis of parallel conduction 2 .…”

“…Moreover, since different manufactures may employ different production techniques, foams made of the same parent material may present dissimilar values of s k . In addition the deviation between k s and s k can be even induced by the presence of impurities [56] or micropores within the solid matrix [57]. Unfortunately, the intrinsic solid phase thermal conductivity is usually not experimentally measured.…”

Investigation of the Relationship between Morphology and Thermal Conductivity of Powder Metallurgically Prepared Aluminium Foams

“…The parameters of the microstructure inside the foam and the properties of those porous structures are related qualitatively in most of the previous studies [5,6]. In all these studies, porosity is dealt with as the significant parameter influencing the porous structure's thermal conductivity, and most of the empirical equations are based on porosity [6,7]. Apart from porosity, pore strut influence on thermal conductivity and the micropore effect are also studied [7,8].…”

“…In all these studies, porosity is dealt with as the significant parameter influencing the porous structure's thermal conductivity, and most of the empirical equations are based on porosity [6,7]. Apart from porosity, pore strut influence on thermal conductivity and the micropore effect are also studied [7,8].…”