熔融石英坩埚在烧结和铸锭过程中的结构及性质

Structure and Properties of the Fused Quartz Crucibles for Silicon Ingots in Sintering and Casting Process

通过X射线衍射测试、薄片观察、SEM形貌分析、显气孔率和体积密度测量等方法,对熔融石英坩埚在烧结和铸锭过程中的物相、结构和性质变化进行了表征;为提高坩埚的强度和致密性,分别进行了烧结实验和硅溶胶浸渍实验。在本实验条件下,α-方石英的(101)衍射峰强度与坩埚结晶度呈线性相关(相关系数r=0.9999),可应用于坩埚结晶度的检测;保温时间为6 h时,坩埚烧结的上限温度为1170℃,此时其结晶度为0.6%;比较了不同的硅溶胶浸渍方式对于坩埚致密度的影响,其中真空浸渍效果较明显,使得坩埚的显气孔率下降13%,体积密度上升7%。

The phase,structure and properties change of fused silica crucible in the sintering and ingot casting processes were analyzed by the X-ray diffraction（XRD）,polarizing microscope,scanning electronic microscope（SEM） and the tests of apparent porosity and volume density.To improve the strength and density of the crucible,the sintering experiments and the silica sol impregnation experiment were carried out.The results of analysis indicate that the intensity of α-cristobalite in（101） face of XRD pattern has a linear correlation with the crystallinity of crucible（correlation coefficient is 0.9999）,which can be applied to the detection of the degree of crucible＇s crystallinity.The upper limit temperature of the crucible is 1170 ℃ when the holding time is 6 h,and the crystallinity of crucible is 0.6% under this condition.The influence of different silica sol dipping method on the density of the crucible were compared,and the effect of vacuum impregnation is obvious,the apparent porosity of the crucible is decreased by 13% and the volume density is increased by 7%.