| At present,in the field of daily ceramics,spodumene is widely used in the production process of spodumene heat-resistant ceramic products due to its extremely low thermal expansion coefficient and excellent thermal shock resistance.With the improvement of the quality of life,the market demand for spodumene ceramic products is increasing day by day,but the price of spodumene mineral resources has remained high,which has greatly increased the production cost of spodumene ceramic products.At the same time,spodumene ceramic materials are consumables,in order to effectively relieve the pressure of market demand,it is necessary to find effective methods to improve their product quality.Therefore,it is necessary to explore and study spodumene ceramic materials from the preparation process and to improve their thermal shock resistance at the same time.In this paper,the solid phase sintering method is used to prepare spodumene ceramic materials,and the sintering system is explored,that is,the sintering temperature is 1180℃,1210℃,1240℃,1270℃and 1300℃,the holding time was 60 min,90 min and 120 min,and the effects of heating rates of 4℃/min,5℃/min and 6℃/min on the microstructure and mechanical properties.At the same time,by adjusting the ratio of spodumene（30 wt.%-50 wt.%（span:5 wt.%））,talc（1wt.%-9 wt.%（span:2 wt.%））and quartz（1wt.%-9 wt.%（span:2 wt.%））,the influence on the thermodynamic properties was studied.The thermal shock resistance of spodumene ceramics was evaluated reasonably,which can provide theoretical guidance for industrial production and preparation of spodumene ceramics.The specific results are as follows:（1）Compared with the formula and preparation process of traditional spodumene ceramics,the bending strength of samples prepared by different sintering systems within the experimental range meets the performance requirements of daily porcelain.The improvement of thermal shock resistance of lithium ceramics is marked by the appearance ofβ-spodumene solid solution crystal phase with low thermal expansion coefficient.Therefore,the sintering temperature range can be optimized as 1210℃-1270℃（lower than the traditional 1300℃）,and the heating rate at high temperature stage is optimized as 4℃/min-6℃/min（the traditional rate is 4℃/min）.The decrease of sintering temperature is beneficial to reduce production energy consumption,the increase of heating rate is beneficial to improve production efficiency,and the widening of sintering temperature zone and heating rate range is beneficial to reduce production difficulty.（2）The thermal expansion coefficient（CTE）of spodumene ceramics decreases with the increase of spodumene content.When the content of spodumene was 40 wt.%,the CTE was 1.73×10-6/℃,which meets the standard of low thermal expansion ceramic materials.When the fixed sintered spodumene content was 40 wt.%and talc content was 7 wt.%,the CTE of spodumene ceramic material was 1.62×10-6/℃.When the quartz content was 7 wt.%,the CTE was1.69×10-6/℃.Adjusting the ratio of talc to quartz can effectively reduce the thermal expansion coefficient of spodumene ceramic materials.The optimal formula was 40 wt.%-50 wt.%spodumene（conventional spodumene is 40 wt.%）,7 wt.%talc and quartz.（3）After 20 cycles of thermal shock experiments at room temperature to900℃.When the spodumene content were 30 wt.%and 40 wt.%,the loss rates of bending strength of spodumene ceramic were 31.48.%and 15.91%,respectively.When the fixed spodumene content was 40 wt.%,talc and quartz content was 7 wt.%,the loss rates of bending strength were 12.75%and 17.70%,respectively.When the content of spodumene is 40 wt.%and talc was 7 wt.%,the spodumene ceramic sample has excellent thermal shock resistance. |
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