Computer Simulation of Directional Solidification of Binary Alloy Calculated under Personal Computer Platform

摘要

The objective of this paper is to demonstrate the ability of simulating thermal-solute double diffusivities problem, which is usually calculated via mini-supercomputer or supercomputer, by using typical personal computer (PC). The "plume" phenomena due to buoyant force of lighter liquid solute during solidification will be illustrated. The conduction, convection and macrosegregation predicted by numerical simulations of a directionally solidified binary alloy (Pb-23.2 wt% Sn) are calculated on Pentium-4 1.6 GHz Personal Computer (PC) platform and presented. The casting was solidified at a rate of 6 μm s~(-1) and a thermal gradient of approximately 7.2 × 10~3 Km~(-1) which is a rather high thermal gradient that has not been numerical simulated before. The calculated results showed channels at the vertical casting surface and segregated internal pockets in the mushy zone, in agreement with the observation of freckles in the experimental casting. They also showed plumes phenomena at the early stage of solidification process. The simulator calculates a set of equations. They are mass conservation, momentum, energy and solute equations. The simulator ported to IBM-compatible PC platform can provide instant information on casting process for manufacturers as compared to obtain calculations under Convex C240 mini-super computer before.