Effect of addetive materials on the foaming behavior, cell structure and mechanical properties of Al2O3-ZrO2

Polymeric sponge replication method is one of the routes that produce ceramic foams. Existence of central triangular voids in struts causes to decrease of mechanical properties and limit their applications. To remove this defect, some additives which consist of Al powder particles and silica sol were added to ceramic slurry which contains Al2O3 and ZrO2 (partially stabilized zirconia). With increasing temperature for pyrolyzing and sintering raw materials, at first, Al powder and glass phase were formed from Al2O3, ZrO2 and SiO2 was melted and was soaked into hollow struts.SEM investigations showed that center of foam struts was free of hollows.XRD considerations depicted there was ZrO2 phase with tetragonal crystallographic structure in the produced foam which could be caused to improve mechanical properties and toughness. Compressive strength of foams increased significantly because of decreasing closed porosity.Weibull statistical study showed remarkable increasing of Weibull module which this value for foams with 10, 20 and 30 ppi was 5.91, 6.06 and 6.53 respectively.