Comparison on Porosity Percent, Microstructure and Compression Behavior of Steel Foams Containing 2 wt. % Cu and 2 wt. % P

In this work, the effects of addition of 2 wt. % Cu and 2 wt. % P on the porosity percent, microstructure, and mechanical properties of 0.5 wt. % C steel foams manufactured by powder metallurgy through urea granulates as space holder were separately investigated. After manufacturing steel foams, determination of porosity percent by dimensional measurement, microstructural evaluation through optical and scanning electron microscopes, and investigation of mechanical behavior by compression test were conducted. The average of porosity percent in steel foams with Cu and P are 75 and 80 percent, respectively. In microscopic evaluations, two types of cells were observed that consisted of the solved urea cells and pores in the cells walls. In addition, the thickness of the cells walls was approximately measured from 90 to 102 micron. In the compressive stress vs. strain curves of Cu and P added steel foams, a long plateau region was observed. It is noteworthy that plateau region in the P added steel foams was as teeth-saw shape that related to the fracture of cells walls.