Making Hollow Cylindrical Products of High-Porosity Silicon Nitride by the Centrifugal Forming of Granules of a Thixotropic Thermoplastic Slip

Resumo

This article describes features of the manufacture of high-porosity silicon semifinished products in the form of hollow cylinders by the warm centrifugal casting of elements obtained from cutting up castings of a silicon-based thermoplastic slip. Silicon nitride obtained by plasmochemical synthesis is added to the slip to impart the necessary rheological properties. Products in the form of hollow cylinders with walls made of a highly porous silicon nitride material are obtained from the semifinished products by removing the binder through sublimation and then subjecting the semifinished products to reaction sintering in nitrogen. The areas of application proposed for the material and the hollow products obtained from it: porous partitions for the filtration and combustion of natural fuels in power plants; porous inserts for the local reinforcement of die-cast products made of light metals.