COLD-HOT ISOSTATIC PRESSING OF MAR M200 SUPERALLOY POWDERS

Powder metallurgy based on cold isostatic pressing, vacuum sintering a nd hot isostatic pressing (HIP) reveals the possibilities of mass prod ucing critical parts in near net shape. The multi-stage process consis ts of: (i) cold isostatic compaction to a green preform; (ii) supersol idus vacuum sintering of compact to more than 90% density; and (iii) f inal consolidation via hot isostatic pressing to densify the preform. Three-point flexural tests were carried out on the sintered and HIPped specimens. Microstructure and porosity evaluations were conducted usi ng scanning electron microscopy and image analysis. (C) 1997 Published by Elsevier Science S.A.