PROCESSING AND PROPERTIES OF HIGHLY POROUS 17-4 PH STAINLESS STEEL

Abstract

Highly porous 17-4 PH stainless steel having porosities in the range of 39-82% with an average pore size of around 700 mu m was successfully fabricated using space holder technique in powder metallurgy. Irregular carbamide particles were used as a space holder material. The final porosity was directly related to the added fraction of carbamide. The specimens were sintered at either 1300 degrees C or 1350 degrees C for times of 60 and 90 min in hydrogen atmosphere. In this porosity range, Young's modulus and compressive strength of the specimens before aging treatment found to be in the range of 0.17-5.34 GPa and 24-290 MPa, respectively and decreased with increasing porosity. 0.5 wt.% boron addition to the 17-4 PH steel powders lowered the sintering temperature and time. The relationship between the mechanical properties and the relative density of porous 17-4 PH steel was found to obey the power law relation.