Purple Pot Bile Toughening Research And Thermal Shock Resistance

In this study, zisha soil is the main raw material, Silicon carbide, spodumene, ceramic fiber,and Henan soil are used as the auxiliary materials, and the zisha pottery samples that have theproperty of good thermal shock resistance and impact toughness are prepared by ordinaryceramic processing principle. That the original SiCp and oxidized SiCp respectively affect onthe mechanical performance and thermal conductivity performance of samples for zisha potteryare researched comparatively, the results decided the oxidized modification SiCp as the thermalconductivity material for this study. The changes, which the water absorption, shrinkage,flexural strength, thermal conductivity, conservation rate of the thermal shock strength, thermalexpansion coefficient and impact toughness have produced, are studied. The relatedperformance of the zisha pottery samples are tested and characterized through the modern testanalysis tools such as SEM, EDS, XRD, OM. The research results show:（1） The surface of SiCp has formed membrane layer of amorphous SiO₂, and the interfaceproperty between zisha and SiCp is that the oxidized SiCp is superior to the original SiCp. Thetwo groups of performance comparison experiment, which one is incorporated by the originalSiCp, the other is the oxidized SiCp. When the content of SiCp is4%, the flexural strength of thelatter reaches to its maximum70.20MPa, the former, however, decreases with the content of SiCpincreasing. The variation of the thermal conductivity for the two groups of experiment appearsfirstly increase, and then decrease, both of them attain to their maximum4.12W/m·k and4.63W/m·k when the content of SiCp is16%.（2） The spodumene that has the function of fluxing can decrease sintering temperature.The zisha pottery’ s sintering temperature reduces from1120℃to1080℃with the content ofspodumene increasing to8%, which no longer reduces when the content of spodumene exceed8%, however, the firing range becomes more and more narrow. The flexural strength at roomtemperature reaches to its maximum83.37MPa when the content of spodumene is16%. Theconservation rate of the thermal shock strength attains to its maximum53.07%meanwhile thethermal expansion coefficient is the lowest and the thermal shock resistance is the best when thezisha pottery samples contain24%spodumene. Both of the surfaces and cuts appearmicrocracks after thermal shock, but the thermal shock damage degree of the cuts is slightlybetter than the surfaces, the intergranular is the main fracture mode, microcracks along the graindeflection improves the thermal shock resistance of the zisha pottery samples. The crystallinephase content of mullite and β-spodumene solid solution in the sintered samples are raisedwith the increase of spodumene and the raising of sintering temperature.（3） The flexural strength and impact toughness of the zisha pottery samples show a trendof increase first and then decrease. Both of them attain to their maximum87.99MPa and 4.07×10^-2J/mm²when the content of ceramic fiber is respectively6%and9%. With the improveof the ceramic fiber, the crystalline phase content of mullite in the sintering phase will beincreased. The regular distribution of ceramic fiber in the zisha pottery samples becomes worsewith the contents increasing. The fiber agglomeration also becomes more serious and there isthe phenomenon of bridging in the matrix when the content of ceramic fiber is12%so that theflexural strength and impact toughness decline. Debonding and pullout effect of the fiber are themain toughening mechanism for the zisha pottery samples.