Polymorphism of Iron at High Pressure

Abstract

Propagation of compressive waves generated by high explosive in Armco iron may, under certain conditions, occur with three stable shocks, which are characterized by abrupt and possibly quasi-discontinuous change of pressure. The characteristics of these have been investigated experimentally and found to be consistent with the hypothesis of a polymorphic transition in iron at about 0.13 megabar. The same phenomenon has been observed in mild steel.