Character of porosity of compact materials obtained from metalorganics

Abstract

The possibility of obtaining highly porous (60–80% pores) materials by combining techniques of powder metallurgy with chemical-metallurgical processes of formation of nanodimensional activators of sintering during the thermal destruction of metalorganics is shown. It is noted that, irrespective of the composition of starting charges, the surface porosity of such materials is represented by pores <30 μm, the fraction of which does not exceed 1%. The basis (86–89%) is represented by pores <4 μm. The character of porosity inside the sintered articles is determined by the sizes and shape of the powderlike skeleton material introduced into the starting charge to prevent the outflow of metalorganics during thermal treatment. When using powders with highly developed particle surfaces as such, the character of the internal porosity is similar to the surface porosity. The combination of scale particles up to 100 μm in size and highly dispersed (<10 μm) particles promotes the formation of long porous channels (100–350 μm) 10–50 μm in width.