工艺参数对Al-Zr中间合金中初生Al3Zr相的影响

以Al-K2ZrF6为反应体系，采用Al热还原法，研究了不同工艺参数对Al-Zr中间合金凝固过程中初生Al3Zr相的形貌、尺寸、数量及分布状态的影响.结果表明:随着熔体反应温度的增加，Al3Zr晶体的形貌由小块状逐渐长成长条状，尺寸增加，数量减少；当温度低于1000℃，晶体呈现小块状；温度高于1000℃时，晶体呈现长条状；温度为1000℃时，晶体呈现块状和长条状的混合态.与使用铁模相比，采用耐火材料模时，Al3Zr相尺寸增大，数量减小.随着K2ZrF6加入量的增加，Al3Zr相的体积分数增多，尺寸更细小，分布更均匀.

Effects of Process Parameters on Primary Al3Zr Phase in Al Zr Master Alloys

The effects of processing parameters on the morphology， size， amount and distribution of the primary Al3Zr phase during the solidification of Al Zr master alloys were investigated by the aluminothermic reduction method in the Al K2ZrF6 reaction system. The results showed that the morphologies of the primary Al3Zr crystals transformed from the small blocky shape to long strip shape， and the size of the primary Al3Zr increased while their amount decreased， with the increase of the molten reaction temperature. When the reaction temperature was below 1000℃， Al3Zr crystals exhibited small blocky shapes; when the temperature was higher than 1000℃， they displayed long strip shapes; when temperature was 1000℃， they displayed the small blocky and long strip mixed morphologies. The sizes of the Al3Zr became larger and the amounts of them became fewer in the refractory mold in comparison to that in the iron mold. With the increase of the K2ZrF6 content， the volume fraction of Al3Zr phase increased gradually， and these crystals grew much finer and with more uniform distribution in the Al matrix.