Porosity has been frequently observed in solidified, deep penetration pulsed laser welds. Porosity is detrimental to weld quality. Our previous study shows that porosity formation in laser welding is associated with the weld pool dynamics, keyhole collapse, and solidification processes. The objective of this paper is to use mathematical models to systematically investigate the transport phenome...

Avoiding particle entrapment into the solidifying shell of a steel continuous caster is important to improve quality of the continuous cast product. Therefore, the fluid flow dynamics in the steel melt and mushy zone, heat transfer and solidification of the steel shell, as well as the motion and entrapment of inclusion particles during the casting process were investigated using computational m...

Nowadays, dynamic solidification models of continuously cast steel are commonly used in steelworks over the world to control the casting process and to monitor the steel production. Moreover, these models of transient temperature field can also be utilized for optimization of continuous casting, its on-line regulation, or may help operators to solve non-standard or breakdown situations that can...

Throughout the past few years the problem of solidification of a melt via nucleation has been addressed in colloidal systems mainly suspended in a fluid, which are known to undergo crystallization and have received considerably interest outside the colloid community. Despite the great deal of work, the microscopic details of the crystallization process are still not completely understood. A ver...

The nucleation mechanism involving rapid solidification of undercooled La-Fe-Si melts has been studied experimentally and theoretically. The classical nucleation theory-based simulations show a competitive nucleation process between the α-(Fe,Si) phase (size approximately 10 to 30 nm) and the cubic NaZn13-type phase (hereinafter 1:13 phase, size approximately 200 to 400 nm) during rapid solidif...

In the present work, heat transfer coefficients (h) along different cooling zones of a continuous caster billet machine were determined during casting of low and medium carbon steels. The effects of casting parameters, such as machine characteristics, the ingot dimension, mold, sprays zones, radiant cooling, melt composition and casting temperature were investigated and correlated with heat tra...

The nucleation undercooling of TiB₂/7075 Al matrix composites, the microstructure observed after solidification at different cooling rate, and the size and distribution of TiB₂ particles were investigated. The experimental results have shown that the grain sizes of TiB₂/7075 Al matrix composites firstly decreased, then increased, and finally decreased again with the increase of TiB₂ content. Th...

  Abstract:   The aims of this research were to investigate the effects of semisolid metal (SSM) processing parameters (i.e., shear rates –times – temperatures combinations) on the primary solidification products and isothermal holding duration, subsequent to cessation of stirring on the secondary solidification of Al-Si (A356) alloy.   The dendrite fragmentation was found to be the governing m...