An experimental study on mid-high temperature effective thermal conductivity of the closed-cell aluminum foam

•Effective thermal conductivity (ETC) of aluminum foam is measured from 100 to 500 °C.•Differences exist in cell wall thermal conductivity (CWTC) among tested foams.•ETC is product of CWTC, relative density and reciprocal of squared tortuosity.•Tortuosity is weakly dependent on density in concerned density range.•ETC and CWTC decrease with temperature increasing.

In this work, the Effective Thermal Conductivity (ETC) of closed-cell aluminum foams was measured in the temperature range of 100–500 °C. Analyses showed that the ETC is proportional to the relative density as well as the cell wall thermal conductivity, and is inversely proportional to the square of the tortuosity. Differences in the cell wall thermal conductivity were found among the foam samples. As the thermal conductivities of Al, Ti2Al20Ca and Al4Ca in the cell wall decrease with temperature and hydrogen-related phase transition occurs, the measured ETC decreases with temperature.