Quantitative Estimation of Mullite in Alumina Based Porcelain Insulators Samples

Although porcelain insulators in power lines have been in use for decades, several undergo catastrophic failures while early in service. A study addressing the materials aspects has been conducted on alumina based porcelain insulators. Apart from their electro mechanical stability characteristics, material aspects like composition, phase and microstructure play a very important role in their performance. The qualitative phase analyses on the insulator samples give an idea about the different major and minor phases present. Attempts have already been made to estimate α alumina and α quartz content in porcelain body. Mullite is another important phase present in the porcelain body, which gets formed during firing of raw materials during insulator manufacture and which has not been estimated quantitatively. An attempt has been made here to assess the mullite content in the alumina based insulator samples by X-Ray diffraction quantitative analysis. Internal standard method of quantification has been adopted successfully for the analysis. This article describes the quantification of mullite phase by the internal standard method based on X-Ray diffraction principle.