English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Metal foams are attractive materials for thermal insulators because of their low thermal conductivity. Coefficient of thermal expansion (CTE) of metal foams is the same as that of cell wall materials. Therefore, the effect of thermal stress induced by a change in CTE, which is severe in the thermal barrier coating by ceramics, becomes negligible. In this study, we focus on designing metal foams as thermal insulators. The effect of porosity and pore shape on the thermal conductivity was calculated by micromechanical analysis. It was revealed that oblate spheroidal pores are effective to decrease the thermal conductivity. Micromechanical analysis also revealed that the thermal conductivity can be controlled by pore distribution of the metal foam. That is, metal foam with graded porosity has low thermal conductivity compared to uniform porosity. A diffusionbonding process enabled to manufacture 5083 aluminum alloy preforms containing TiH2 particles as a foaming agent. Foaming test by directional heating enabled to manufacture closedcell 5083 aluminum alloy foams having both oblate spheroidal pores and graded pore distribution.

Effect of Graded Pore Distribution on Thermal Insulation of Metal Foam