ANÁLISIS Y SIMULACIÓN DEL MODELO TÉRMICO Y VISCOSO DEL PROCESO DE MELT SPINNING

AXEL LARRETEGUY; MARCELO BARONE; JAIRO USCECHE; MARCELO PAGNOLA; FRANCISCO BARCELÓ

Congreso; XI CONGRESO COLOMBIANO DE MÉTODOS NUMÉRICOS; 2017

Melt Spinning process is used for thin ribbons of amorphous materials manufacture. The material is ejected through a nozzle in liquid state and it solidifies in contact with a rotating wheel. The intention of this paper is to find out, through a computer simulation consisting of Open FOAM®, a thermal profile of the material from its ejection through the nozzle to the forming process of the tape itself. A two-phase model named ?Volume of Fluids? (VOF) is used. Despite the fact that both fluids (liquid metal and air) can´t be considered to be compressible. A solver was used for compressible fluids. Since it allows to represent density changes in the air due to modifications in temperature values and to define a thermo-physical model for the alloy that is not available in an incompressible solver. Thus it is considered to be an alloy of constant thermal conductivity and specific heat and density. Phase change is represented by a model that relates viscosity (μ) to temperature (T) in which viscosity increases in several orders of magnitude when the material passes below the crystallization temperature. Among viscous model options offered by OpenFOAM®, a polynomial model is selected which coefficients were determined after expanding the relation μ=-a(T-T^* )^7+μ^*. By using OCTAVE, a coefficient, T^* and μ^* values were modified until getting an adjustment curve [1] with the expansion function in order to obtain the final polynomial coefficients within the temperature range of 600ºC to 1700ºC.