Applications of atom-probe field-ion microscopy to the study of interfaces
The near-atomic resolution and elemental sensitivity of the atom probe field-ion microscope (APFIM) permit the detailed microstructural and microchemical analysis of phases and interfaces in a variety of materials. To overcome the limitation of this technique in terms of volume of material sampled, it is frequently necessary to perform complementary microstructural studies by other techniques such as analytical electron microscopy (AEM) or auger electron spectroscopy (AES). With such complementary data, the microstructural significance of the APFIM data can be exploited. In addition to specifically evaluating segregation at interfaces, the high spatial resolution of the APFIM technique can be used to determine microcompositional fluctuations in the vicinity of interfaces. In this overview, some selected examples illustrating the application of the APFIM technique to the evaluation of segregation to interfaces are presented.Considerable research has been performed on low alloy steels, particularly those such as A533B which are used in the pressure vessels of nuclear reactors.