Porosity behaviour of insulated iron powder compounds

The goal of the present paper is to determine the porosity behavior of new development insulated iron powder compounds without and with different additions of aluminum alloy Alumix 321 (5 and 10 wt%). A significant disadvantage of PM processing is the presence of porosity. Pores act as crack initiators and, due to their presence, the distribution of stress is inhomogeneous across the cross-section and leads to the reduction of the effective load bearing area. Quantitative image analysis of investigated material treats pores as isolated plane two-dimensional objects in solid surroundings. To describe the dimensional and morphological porosity characteristics, the dimensional characteristic D_{circle} and the morphological characteristics f_{shape} and f_{circle} were explored. Both the morphology and the distribution of pores shows a significant effect on the cold welding or appropriate bonds between adjacent particles.