Manufacturing of Steel Foams through Powder Metallurgy Technique by Urea Granules as Space Holder

In this work, the steel foams were manufactured through powder metallurgy technique by urea granules as water leachable space holder. Firstly, the mixture of commercial iron, copper (1 wt. %), and ultrafine carbon (0.5 wt. %) powders was prepared. Then, the spherical urea granules were coated with powders mixture and the process was followed by compacting and water leaching the urea space holder. Finally, the sintering process was carried out into a special furnace. The microstructural properties were investigated by scanning electron microscope (SEM) and the compression tests were conducted on the manufactured steel foams. The porosity percent of the steel foams was measured between 68 to 77 %. In the manufactured steel foams, two types of pores were observed that consisted of the pores between the sintered powders and cells formed base on the leaching the urea granules. In addition, the compression behavior of manufactured steel foams were shown the normal behavior of metal foams. Also, the compression tests were revealed the saw-tooth stress vs. strain curves.

Keywords:

Steel foam , Powder Metallurgy , Space Holder , Porosity , Microstructure , Compression behavior