Determination of impurities in sintered fine ceramics by ICP-AES

A few decomposition methods were examined in order to determine impurities in sintered alumina, zirconia and alumina/zirconia composite samples. Pulverized samples were severely contaminated by a grinding vessel. A lump (about 0.3 g) of sintered alumina or zirconia sample was decomposed with 10 mi of sulfric acid (1 + 2) in a Teflon pressure vessel at 230 degrees C for 16 similar to 60 h; however, all sintered alumina/zirconia composite samples were not decomposed with sulfric acid (1 + 2). A lump (about 0.3 g) of the sintered composite sample was decomposed with a mixture of 0.3ml of hydrofluoric acid and 9.7 mi of sulfric acid (1 + 2) at 230 degrees C for 24 h. It was necessary to match the matrix components (acids, aluminum and zirconium) in standard solutions to those in sample solutions. The proposed methods were applied to several commercial samples, and the impurities and additives were determined by ICP-AES. The detection limits of most elements were below several mu g/g. The decomposition methods for sintered silicon carbide, silicon nitride, aluminum nitride, boron nitride, zinc oxide, barium titanate, lead zirconate titanate and sialon were also described.