ABSTRACT
Massive transformation is one in which the product phase has the same composition as the matrix and the migration mechanism of the interphase boundaries is (short-range) diffusion across these boundaries. In 1930, Phillips published a brief and modest paper [1] on transformations in brass in which he established the basic characteristics of the massive transformation. Quenching a Cu-38 wt% Zn alloy from 8508C into iced brine, he observed that the structure consisted of large units of a rather than of b brass, see Figure 5.1. Etching, plastic deformation, and further heat treatment were used to confirm the identity of the a crystals. ‘‘This result may be explained by assuming that the transformation of b into a, where no change of composition is concerted, can take place with great facility even at a rather low temperature.’’ Only the structure of the interphase boundary, which allowed transformation to proceed so freely, and the ability of the massive transformation to occur in the two-phase region in some systems remained to be established after Phillips’ investigation.
