Al2O3 aerogel coating modified TiH2 to enhance the mechanical properties of aluminum foam

Abstract

Al2O3 aerogel coating modified TiH2 (Al2O3 aerogel-TiH2) was successfully fabricated by emulsion-gelation technique and used as foaming agent to enhance the mechanical properties of Al foam. Mesoporous Al2O3 aerogel, with specific surface area of 460.3 m2 g−1 and average pore size of 3.15 nm, is an effective thermal insulation barrier for TiH2 foaming agent. The results show that the maximum decomposition temperature of Al2O3 aerogel-TiH2 is increased to 581 °C, which is 16 °C higher than that of pristine TiH2 (565 °C). Furthermore, Al foam prepared by Al2O3 aerogel-TiH2 has smaller cell size and more concentrated cell size distribution compared with that using TiH2 as foaming agent. These improved structure characteristics enhanced the Al foam mechanical properties. The compressive strength and energy absorption capacity (compressive strain was 50%) of Al foam fabricated with Al2O3 aerogel-TiH2 are 5.59 MPa and 5.51 MJ m−3, comparing that are 1.63 MPa and 1.26 MJ m−3 of Al foam obtained with TiH2.