| Abstract Scope |
In this paper, a CAFE model of solidification microstructure evolution in Vacuum Arc Remelting process is established considering heat transfer, flow and solute diffusion. The effects of melting speed, upper surface temperature and cooling intensity on solidification structure were studied. The results show that: There are typical three crystal regions in the solidification microstructure of titanium alloy ingot by Vacuum Arc Remelting, namely surface fine crystal region, columnar crystal region and central equiaxed crystal region. With the increase of melting speed, the overall morphology of ingot structure is basically the same, but the width of columnar crystal decreases gradually, and the width of central equiaxed crystal increases gradually. With the increase of melting speed, the number of grains in ingot structure gradually increases, and the average area of grains gradually decreases. The effect of upper surface temperature and cooling intensity on solidification structure of ingot is not obvious. |