Point defects in binary C15 and C14 systems, on both sides of stoichiometry, were studied by performing bulk density and X-ray lattice parameter measurements. It was found that the vacancy concentrations, after quenching from 1000C, were essentially zero (table 11). The constitutional defects, on both sides of stoichiometry, were found to be of antisite type. There were essentially no thermal vacancies after quenching from 1300C. Antisite hardening was found on both sides of stoichiometry. Neither the antisite defects nor the thermal vacancies significantly affected the fracture toughness.

Point Defects in Binary Laves Phase Alloys. J.H.Zhu, L.M.Pike, C.T.Liu, P.K.Liaw: Acta Materialia, 1999, 47[7], 2003-18

Table 11

Vacancy Concentrations in Fe2Nb Quenched from 1000C