Abstract: Porous acoustic ceramic was prepared with magmatic soil , tuff and glass power as the main raw materials.Silicon carbide and straw powder were used as the foaming agent and pore-forming agent, respectively .Based on the thermal analysis of raw materials , single factor method was employed to study the effects of sintering temperatures , holding time, dosage of pore forming agent , amount of foaming agent , sample thickness ,porosity and pore size on the properties of the sample sound absorption property . X-ray powder diffraction ( XRD) and ultra depth of the field techniques were used to characterize the phase compositions and morphology of sintered samples .The results show that favorable performance of porous acoustic materials could be achieved by optimized conditions , with sinter at 1150 ℃ for 50 min, the forming agent and pore-forming agent is 1.4;and 6;, and the sample thickness is 30 mm.For this optimal sample, the average sound absorption coefficient is 0.34 assess at the frequency of 200-4000 Hz. Furthermore , the first sound absorption peak shifted to low frequency direction gradually when the sample thickness is increase .

Key words: Porous acoustic ceramic was prepared with magmatic soil , tuff and glass power as the main raw materials.Silicon carbide and straw powder were used as the foaming agent and pore-forming agent, respectively .Based on the thermal analysis of raw materials , single factor method was employed to study the effects of sintering temperatures , holding time, dosage of pore forming agent , amount of foaming agent , sample thickness ,porosity and pore size on the properties of the sample sound absorption property . X-ray powder diffraction ( XRD) and ultra depth of the field techniques were used to characterize the phase compositions and morphology of sintered samples .The results show that favorable performance of porous acoustic materials could be achieved by optimized conditions , with sinter at 1150 ℃ for 50 min, the forming agent and pore-forming agent is 1.4;and 6;, and the sample thickness is 30 mm.For this optimal sample, the average sound absorption coefficient is 0.34 assess at the frequency of 200-4000 Hz. Furthermore , the first sound absorption peak shifted to low frequency direction gradually when the sample thickness is increase .