Formation of stray grain defects particularly around re-entrant features of the turbine blade airfoils is one of the major problems in directional and single crystal solidification processes. In this work, directional solidification tests of the GTD-111 Ni-based superalloy were conducted at different withdrawal velocities of 3, 6 and 9 mm.min-1 using various stepped cylindrical and cubic design...

The directional solidification of the transparent binary alloy succinonitrile-poly(ethylene oxide) was studied in an experiment in which solidification speeds of about 2 mm/sec could be reached without loss of the linear temperature gradient. The low diffusivity of the polymer solute allowed the study of the dynamics of rapid solidification using an optical microscope. For both normal and doubl...

The Directional Solidification is a very important technique for growing high quality multi-crystalline silicon at large scale for PV solar cells. The physics governing the growth of multi-crystalline silicon in the Directional Solidification System involves complex non-linear transport phenomena including but not limited to heat transfer, solidification, thermal stress development, and the for...

2014 We have studied the morphology of the solid-liquid interface during the directional solidification of thin (5-150 03BCm) samples of a dilute binary mixture (CBr4/~ 0.1 % Br2) . Above a critical pulling speed, for a given temperature gradient and solute concentration, the interface, initially planar, breaks down into a periodic cellular pattern. The bifurcation from a planar to a cellular s...

The solidification of gamma TiAl alloys is of interest to the aerospace and automotive industries. A gamma TiAl multicomponent alloy: Ti–45.5Al–4.7Nb–0.2C–0.2B (at. %) has been the focus of a study to investigate the solidification conditions that led to a Columnar to Equiaxed Transition (CET) in a directional solidification experiment where traditional Bridgman solidification was combined in s...

Directional solidification of metal-gas eutectic (Gasar) is a novel process for making regular porous metals. This process is based on a solid-gas eutectic reaction involving a gaseous medium and a metal or a ceramic phase, and allows an easy control of the porosity, such as its pore size, pore orientation and morphology in a wide range by properly adjusting its melting and solidification condi...

A numerical study of directional solidification has been performed using a fixed-grid front-tracking algorithm. The directional solidification of pure tin, as well as the horizontal Bridgman growth of pure succinonitrile, were investigated. In both cases, the growth front was stable and non-dendritic, but was significantly distorted by the influence of convection in the melt and, for the Bridgm...