论文部分内容阅读
用扫描电镜(SEM)以及能谱分析方法(EDAX)研究了经不同重熔温度加热并以一定速率定向凝固的高温合金Incond718糊状区液相的显微组织和成分。给出了液相中Nb、Mo沿着糊状区的分布。同时计算了糊状区液相密度差和相对Rayleigh数(Rar)。当重熔温度从1600℃升高到1700℃,Mo偏析加重,糊状区变长,液相密度差在凝固初期变大,糊状区的极大值显著升高,这说明重熔温度提高后热溶质对流趋势增大,糊状区变得不稳定。
The microstructure and composition of the liquid phase of the Incond718 paste-like zone of high-temperature superalloy, which was heated at different remelting temperatures and directionally solidified at a certain rate, were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDAX). The distribution of Nb and Mo along the paste-like zone in the liquid phase is given. The liquid density difference and relative Rayleigh number (Rar) of the mushy zone were also calculated. When the remelting temperature increased from 1600 ℃ to 1700 ℃, the Mo segregation aggravated, the paste area became longer and the liquid density difference became larger at the initial stage of solidification, and the maximum value of the paste area increased significantly, which indicated that the remelting temperature was increased After the hot solute convection trend increases, the mushy zone becomes unstable.