Fabrication and Testing of 105 mm Sintered Iron Rotating Bands 690238

The fabrication process and mechanical testing procedures used by the Frankford Arsenal in production of 105mm sintered iron rotating bands are discussed. It was demonstrated that 105mm bands can be fabricated to meet the class 3 density range of the current military specification (MIL-R-11073) using conventional sintering temperatures (2050°-2100°F) and sintering atmospheres (dissociated ammonia). The major processing requirement was that density must be closely controlled and kept in the upper portion of the density range, approximately between 6.00 and 6.19 g/cc. Two commercial reduced type iron powders were found to be suitable for the production of these bands. The existing methods of test for tensile strength and ductility of bands in the specification appear adequate. A more sophisticated hydrostatic type testing device did not yield more consistent or uniform test data.