Growth and Characterization of High purity FeTi Inter-Metallic Compound Single Crystal

采用坩埚下降法研究了FeTi金属间化合物单晶的生长机制。从含Ti 52.5- 80at%的Fe-Ti母材中生长出晶体。单晶仅从Fe-57.5- 62.5at%Ti母体金属生长。根据母材中Ti含量变化的结构变化，推测约8at%的Ti与石墨坩埚发生反应。以Fe-6Oat%Ti为母材，研究了固液界面附近温度梯度和晶体生长速率对晶体结构的影响。随着温度梯度的增大和生长速率的降低，晶体结构由柱状晶向枝晶转变。结果表明，FeTi单晶的生长机制与固溶体非平衡生长机制相同（无包埋反应）。

Growth mechanism of FeTi intermetallic single crystals was investigated by Bridgman method. Crystals were gorwn from Fe-Ti parent metals which contains 52.5-80 at%Ti. Single crystals were grown only from the Fe-57.5-62.5 at%Ti parent metals. From the structural changes with the Ti concentration of parent metals, about 8 at%Ti is supposed to react with graphite crucible. Stractural changes with temperature gradient near the solid-liquid interface and with growth rate of the crystal were also investigated with Fe -6Oat%Ti parent metals. Structural change of columnar crystal to dendrite single crystal was observed with increasing the temerature gradient and with decreasing the growth rate. It is concluded that FeTi single crystals grow by the same mechanism of solid-solution non-equilibriumly (without peritectic reaction).