【摘要】 :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相的精确测定更多还原

【Abstract】 The preparing process of pure NiAl 3 samples was investigated by means of Solution Leaching (SL) and Equilibrium Solidification (ES) in order to measure the phase composition in Ni Al alloy by XRD. The experimental results showed that the phase mass ratio (NiAl 3: α Al) reaches nearly 1 when the alloy (Ni 11 Al 89 ) melt was cooled down to the solidus temperature at a speed of less than 2 K/h. Using the corrected K value as measured in obtained sample, the content of the NiAl 3 phase in unknown samples of Ni Al alloys can be calculated precisely. For the SL processing, it is very difficult to prepare the pure NiAl 3 phase, when mixed with equivalent α -Al, thus measured K value usually deviated from the real K value by a significant error. Therefore, SL processing can only be applied to the case of approximate measurements.更多还原