Phase Transformations in Metals and Alloys

Abstract

Porter and Easterling have written a superb undergraduate phase transformations text. I happened on an advance copy of the book last summer, and proceeded to use it as a text in our required junior phase transformations course of 45 materials science students, The text was very well received and the students performed well.A great deal of hard, careful work has clearly gone into this book. The topics follow a logical succession, and the derivations are clear, direct, and remarkably free of errors, either mathematical or physical. The book is unusually free of the typos which are so especially unsettling to undergraduates who are seeing material for the first time.The book begins with a chapter on thermodynamics, including free energy versus composition diagrams and binary and ternary phase diagrams. The chapter seems well done, though I did not use it.Diffusion is covered well and at some length, from both the phenomenological and atomistic viewpoints. Several "type" solutions to the diffusion equation are presented, along with an analysis of diffusion in ternary and multi phase systems. The analysis of high diffusivity paths is particularly valuable, as is inclusion of values for activation energies and pre-exponential factors for a number of elements and compounds.The structure, energetics, and kinetics of crystal interfaces are presented in a chapter of their own; both interphase boundaries and boundaries in single-phase solids are considered at length. The effect of interface structure on migration kinetics, particle morphology, and transformation strain energy is covered .

A model for Ti–6Al–4V microstructure evolution for arbitrary temperature changes

“…Phenomena at the microstructure scale are fairly well studied and several relationships between process variables and resulting microstructure have been proposed (Banerjee and Mukhopadhyay 2007;Porter and Easterling 1992). Material and microstructure behaviour models can be grouped in three broad classes (Furrer and Semiatin 2010).…”

“…The model focuses primarily on reproducing correctly the beginning and end of transformation, the intermediate steps are not considered. Arrhenius rate-type equation, used to describe the temperature dependence of a phenomena, is a well-known example (Porter and Easterling 1992). The precise underlying mechanism(s) are not incorporated resulting in needs for calibration of the relationship and risk for inaccurate use when the process mechanism(s) changes.…”

“…A simple grain growth model have been used as part of the physically based plastic flow model, see section 6.2 and Paper E. The model is based on the kinetics of normal grain growth for a single-phase metal for which the rate of grain growth is proportional to the mean grain diameter (Porter and Easterling 1992). The following Equation 5 has been used in the model of the hardening process ).…”

Piezotronic Effect in Solution-Grown p-Type ZnO Nanowires and Films

“…We believe that the formation of dopant basal planes is related to classical precipitation kinetics. 31 In the higher-doped samples, there will be more nucleation events due to the increased dopant concentration. Because of the overlapping diffusion fields of the different nucleation sites in the higher doped samples, the growth rate will quickly drop off leading to smaller dopant planes, and thus smaller voids.…”

In-situ TEM Observation of Repeating Events of Nucleation in Epitaxial Growth of Nano CoSi2 in Nanowires of Si

“…Another reason is that there may exist a heterogeneous defect at the center of the interface which favors a step nucleation. 40 Without including the incubation time of nucleation, on the basis of the measured radial growth rate of 135 nm/sec, the axial growth rate of each CoSi 2 atomic layer is about 1.82 nm/sec. This result shall be obtained by using the following equation as well…”