Crack formation in magnesium oxide single crystals

Abstract

Abstract Experimental evidence is presented which lends direct support to the Stroh mechanism for crack formation. After a magnesium oxide crystal was compressed about 3%, it was observed that minute cracks had been formed in the region of a kink band generated by non-homogeneous plastic strain. These cracks lay on conjugate {110} slip planes and not on the usual {100} cleavage planes. They extended in the form of [001] direction slits running right through the crystal.