Fundamentals of Nitriding and Nitrocarburizing
In ASM Handbook (Eds. J.L. Dosset and G.E. Totten), vol. 4A, 2013, Materials Park, Ohio 44073-0002, USA, pp. 619-646
Thermodynamics of Reactions and Phase Transformations at Interfaces and Surfaces
L.P.H. Jeurgens, Z.M. Wang and E.J. Mittemeijer
International Journal of Materials Research 100 (2009) 1281-1307
Analysis of Solid State Phase Transformation Kinetics: Model and Recipes
F. Liu, F. Sommer, C. Bos and E.J. Mittemeijer
International Materials Reviews 52 (2007) 193-212
The progress of solid-state phase transformations can generally be subdivided into three overlapping mechanisms: nucleation, growth and impingement. These can be modelled separately if hard impingement prevails. On that basis, an overview has been given of recent numerical and analytical methods for determination of the kinetic parameters of a transformation. The treatment focuses on both isothermally and isochronally conducted transformations. To extend the range of transformations that can be described analytically, an number of more or less empirical submodels, which are compatible with experimental results, has been included in the discussion. It has been shown that powerful, flexible, analytical models are possible, once the concept of time or temperature dependent growth exponent and effective activation energy, in agreement with the existing experimental observations, has been adopted. An explicit (numerical) procedure to deduce the operating kinetic process from experimental transformation-rate data, on the basis of different nucleation, growth and hard impingement mechanisms, has been demonstrated. Without recourse to any specific kinetic model, simple recipes have been given for the determination of the growth exponent and the effective activation energy from the experimental transformation-rate data.
The "state of the art" of the diffraction analysis of crystallite size and lattice strain
E. J. Mittemeijer and U. Welzel
Zeitschrift für Kristallographie 223 (2008) 552-560
Stress Analysis of Polycrystalline Thin Films and Surface Regions by X-Ray Diffraction
U. Welzel, J. Ligot, P. Lamparter, A.C. Vermeulen and E.J. Mittemeijer
Journal of Applied Crystallography 38 (2005) 1-29
The components of the macroscopic mechanical stress tensor of a stressed thin film, coating, multilayer or the region near the surface of a bulk material can in principle be determined by X-ray diffraction. The various analysis methods and measurement strategies, in dependence on specimen and measurement conditions, are summarized and evaluated in this paper. First, different X-ray diffraction geometries (conventional or grazing incidence) are described. Then, the case of macroscopically elastically isotropic, untextured specimens is considered: from the simplest case of a uniaxial state of stress to the most complicated case of a triaxial state of stress. The treatment is organized according to the number of unknowns to be determined (i.e. the state of stress, principal axes known or unknown), the use of one or several values of the rotation angle ' and the tilt angle of the sample, and one or multiple hkl reflections. Next, the focus is on macroscopically elastically anisotropic (e.g. textured) specimens. In this case, the use of diffraction (X-ray) elastic constants is not possible. Instead, diffraction (X-ray) stress factors have to be used. On the basis of examples, it is demonstrated that successful diffraction stress analysis is only possible if an appropriate grain-interaction model is applied.