:传统的萃取工艺难以制得高纯度的 Ni Al3相 ,将这种 Ni Al3相与等量 α- Al混合后测得的 K值有较大的误差 ,仅适用于测量精度要求不高的情况。为了用 XRD准确测定 Ni- Al合金的相组成 ,作者用萃取和平衡凝固两种方法对 Ni Al3相 K值测定时使用的纯相制备工艺进行了实验研究。研究证实 ,熔融合金以小于 2 K/h的冷却速度缓慢凝固至固相线以下 ,可得到 α- Al与 Ni Al3两相的质量比接近于 1的相组成 ,用此试样测得的 K值经修正后可用于未知试样中 Ni Al3相的精确测定 : The traditional extraction process is difficult to produce high purity Ni Al3 phase, the Ni Al3 phase and the same amount of α-Al mixed measured K values ​​have greater errors, only suitable for less demanding measurement accuracy . In order to determine the phase composition of Ni-Al alloy accurately by XRD, the authors used two methods of extraction and equilibrium solidification to study the pure phase preparation process of Ni Al3 phase K value determination. The results show that the solidification of the molten alloy slowly solidifies to below the solidus phase at a cooling rate of less than 2 K / h, and the mass ratio of α-Al to Ni Al3 is about 1. The K The values ​​are corrected for accurate determination of NiAl3 phase in unknown samples