Technique for differentiating between open and closed pores on a microscopic scale

A technique was developed that allows differentiation between the closed and open pores of a solid. The technique involves impregnating the open pores with nickel carbonyl gas, decomposing the gas to deposit nickel on the surface of the open pores, and ceramographically observing the deposited nickel. The technique was shown to be applicable to pyrolytic carbon, graphite, stabilized zirconia, alumina, and porcelain