Ni-90 superalloy foam processed by space-holder technique: microstructural and mechanical characterization

Abstract

In this study, spherical and between 1400 to 1800 μm carbamide particles coated with Ni-90 superalloys powder were used to produce foam by space-holder technique. Foams with porosity between 60%, 70% and 80 vol.% after mixing and compaction the space-holder particles were extracted using hot water leaching over a range of temperatures. The porous green parts were thermally debound to remove the paraffin wax under a pure argon atmosphere then sintered at high vacuum and subsequently heat treatment were performed. The effects of the volume fraction of space-holder particles on density and porosity were investigated. Microstructures were captured using optical and scanning electron microscopy. Also, compression tests were conducted on the sintered, heat treated samples.