JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.27, sa.2, ss.265-274, 2012 (SCI-Expanded)
In this study, porous surfaces made of SS316L spherical stainless steel powder have been produced to be used in heat exchangers of fuel cells by designing and producing forming die and special punches. Minimum pressure and temperature levels for compacting have been examined to obtain sufficient bonding between powders and the substrate. Moreover, surface roughness of the substrate has been increased in order to bond substrate and the powders. Surface etching techniques have been investigated and minimum surface roughness of the substrates has been defined. Besides, the effects of temperature and pressure on open porosity have been investigated. The experiments and the tests showed that 200 MPa compacting pressure, 500 degrees C temperature and R-a=1.7 mu m roughness, on the substrate are enough to realize such surfaces. Under these circumstances 29.6% porosity has been obtained.