Growth of bulk Si from Si-Al alloy by temperature gradient zone melting

The continuous growth of bulk Si in the Si-Al alloy using the temperature gradient zone melting (TGZM) technique is an effective method to separate the primary Si from the eutectic structure in the Si-Al alloy and to remove the majority of impurities, such as metals, B and P elements during the alloy refining process. A Si source was used to maintain the Si concentration in the alloy melt and reduce the influence of the solute-transmitting process by temperature gradient due to the precipitation of the primary Si. Bulk Si could be obtained in the Si-Al alloy through the TGZM process. With the initial temperature of 1461 K and temperature gradient of 1.81 K/mm, the actual growth rate of the bulk Si was 0.000186 mm/s. No inclusions and alloy phases were observed in the bulk Si. The removal rate of Fe impurity was 99.9% and the removal fraction of B, P and Al was 71.2%, 90.2%, 78.5% respectively.