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. The constitutional defects, on both sides of stoichiometry, were found to be of antisite type. Thermal vacancies which exhibited a maximum at the stoichiometric composition were observed after quenching from 1400C (table 5). 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 5
Vacancy Concentrations in Quenched Cr2Nb
Nb (at%) | Quench Temperature (C) | [V] (%) |
32.3 | 1400 | 0.03 |
32.8 | 1400 | 0.17 |
32.8 | 1000 | 0.03 |
33.3 | 1400 | 0.33 |
33.3 | 1000 | 0.07 |
33.8 | 1400 | 0.17 |
33.8 | 1000 | 0.06 |
34.8 | 1400 | 0.10 |
34.8 | 1000 | 0.00 |