The solidification of concentrated alloys containing ordered compounds is less well understood. These alloys often exhibit complex phase hange like peritectic reaction during liquid to solid transformation. The Fe-rich part of Fe–Ge binary alloy system consists of several critical oints and ordered–disorder transitions and can be used as a model system to study the effect of departure from equi...

The effect of Au addition on the microstructural and the tensile properties of Sn–0.7 mass%Cu alloy was examined. Tensile strength and 0.2% proof stress remarkably increase up to 0.3 mass%Au primarily due to solid solution hardening. Beyond 0.3 mass%Au, due to precipitation of large intermetallic compounds, elongation decreases while tensile strength and 0.2% proof stress increase slightly. Wit...

Recently, titanium-tantalum alloys have been studied as implant materials for dental and orthopedic surgery. However, titanium and tantalum are difficult to mix by common arc melting and induction melting, because of their high melting point and the marked difference between their densities (Ti: 1,680 degrees C, 4.5 g/cm3, Ta: 2,990 degrees C, 16.6 g/cm3). Thus, the Cold Crucible Levitation Mel...

Long-standing challenges in cluster expansion (CE) construction include choosing how to truncate the expansion and which crystal structures to use for training. Compressive sensing (CS), which is emerging as a powerful tool for model construction in physics, provides a mathematically rigorous framework for addressing these challenges. A recently-developed Bayesian implementation of CS (BCS) pro...

We present results from direct numerical simulations of two types of technologically important phase change processes: directional solidification of a binary alloy and film boiling. We use a two-dimensional finite-difference/front-tracking method which allows us to accurately follow the evolution of the interface between the phases. The method is general in the sense that discontinuities in mat...

The coarsening kinetics of nanoscale, coherent Al3ð Sc1 xErxÞ precipitates in a-Al during aging of a supersaturated Al–0.06 Sc–0.02 Er (at.%) alloy at 300 C are studied using transmission electron microscopy and local-electrode atom-probe tomography. Erbium and Sc segregate at the precipitate core and shell, respectively. The matrix supersaturations of Er and Sc, as well as the mean precipitate...

By using laser ablation of the mixtures of a transition metal (M: Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag) plus lead, M/Pb binary cluster anions were observed except for Zn, and the number of transition metal atoms contained in the binary clusters is at most 4. This behavior is different from that reported previously for M/Ge binary clusters. The experiments indicate that it is also very difficu...

The seemingly trivial moving boundary problem of the crystallization of a solid phase from a cooled wall comes under the rubric of the so-called Stefan problems describing a wide range of physical processes. Their rich nonlinear behavior has attracted substantial scientific interest and their ubiquity in fields ranging from metallurgy to geophysics stimulates developing new mathematical approac...

We present adaptive finite element simulations of dendritic and eutectic solidification in binary and ternary alloys. The computations are based on a recently formulated phase-field model that is especially appropriate for modelling non-isothermal solidification in multicomponent multiphase systems. In this approach, a set of governing equations for the phase-field variables, for the concentrat...

Superplastic deformation and high temperature load relaxation behavior of coarse-grained iron aluminides with the composition of Fe-28 at.% Al have been investigated. A series of load relaxation and tensile tests were conducted at temperatures ranging from 600 to 850C. The flow curves obtained from load relaxation tests were found to have a sigmoidal shape and to exhibit stress vs. strain rate ...