FORMATION OF ABRADABLE LAYER OF CASING FOR ROTATING BODY

摘要

PURPOSE:To obtain an abradable layer having extremely good machineability by forming many honeycomb-shaped cavities in the required part of the inside surface of a casing for a cast iron rotating body by making use of a thermit reaction. CONSTITUTION:A fibers 6 cut to a prescribed length are longitudinally arrayed apart from each other at a small space in the part of a casting mold 5 where the abradable layer of a casting for a rotating body is required. Iron rust powder 7 is packed into the spaces between the fibers 6. Molten cast iron 8 is then poured into the mold 5 to cause a thermit reaction between the fibers 6 and the powder 7, thus yielding a casting projected with the cast iron 8' between the brittle alumina 6'... is obtd. The alumina 6'... are washed and scraped out. The abradable layer having good machineability is thus formed in the required part of the cast iron casting.