2 The Basics to Better Understand Couplings in Physical Metallurgy

Pure metals and most alloys are crystallized, in other words, formed by a regular stack of atoms, and we refer to them as “crystals”. The FCC and HCP structures are compact, which means they are formed by a stack of compact planes. The difference between these two structures lies in the sequence of the stack: ABCABCABC... (Figure 2.1(e)) for the FCC structure and ABABAB...