Study on the mechanical properties of porous tin oxide

Abstract

Abstract Despite the importance of tin oxide (SnO 2 ) in diverse functional applications, little information is available on the mechanical properties of bulk or porous SnO 2 . In this study, porous SnO 2 was synthesized using an ice-templating method to produce a “dual” pore structure that comprises large wall pores (on the order of several micrometers) with small micropores (~2 µm) on their surfaces. The Vickers hardness decreased with increasing porosity and increased with increasing contiguity of struts. The compressive stress–strain curves of porous SnO 2 samples with porosity ranging from 48% to 73% were compared with both the Gibson–Ashby and the cellular-lattice-structure-in-square-orientation models, which generally represent the “lower” and “upper” bounds of yield strength for porous materials, respectively. As expected, the yield strength of the porous SnO 2 samples decreased with increasing porosity, and all the yield-strength values of porous SnO 2 fell between the two extreme prediction models. The sample with the lowest porosity of 48% exhibited sharply increasing elastic behavior followed by sudden rupture, as generally reported for bulk ceramics; however, the other samples with higher porosities ranging from 50% to 73% exhibited “porous-metal-like” behavior at strains of 15% or greater as a result of the fracturing of the solid walls between the pores.