Production and characterisation of Cr-Si-Ni-Mo steel foams

Abstract

In this study, production of Cr-Si-Ni-Mo steel foams by space holder-water leaching technique in powder metallurgy is investigated. Cr-Si-Ni-Mo steel powders are mixed with different amounts of carbamide and then compacted at 180 MPa. Polyvinyl alcohol is used as a binder. The carbamide in the green compacts is removed by water leaching at room temperature. The foams having porosities ranging from 39 to 72 % are produced after sintering at temperatures between 1150 and 1250ºC and times of 30 and 60 min in H₂ atmosphere. Young’s modulus and compressive yield strength values of the steel foams are in the range of 0.20-5.21 GPa and 24-290 MPa, respectively. Increasing sintering temperature and sintering time enhanced the Young’s modulus and compressive yield strength of the foams. The relationship between the Young’s modulus and compressive yield strength with the relative density of the foams is found to obey a power law relation.