Ni—Al粉连续加热过程中的反应机理

REACTION MECHANISM OF CONTINUALLY HEATING Ni AND A1 PARTICLES

Ni－Al粉末的差热分析和620℃高温金相原位观察表明：在室温至1000℃范围内，差热曲线存在着三个放热峰和两个吸热峰.第一放热峰系Ni和Al粉末固－固反应生成NiAl3所致；第二放热峰系液态共晶与Ni反应生成Ni2Al3所致；第三放热峰系液相中的Al通过扩散与Ni反应生成Ni2Al3等放热所致；第一吸热峰对应于接触共晶熔化以及Al的熔化；第二吸热峰与NiAl3逆包晶反应相对应.

There are three exothermic peaks and two endothermic peaks in Ni-Al differential thermal analysis (DTA) curves. Three exothermic peaks are respectively attributed to NiAl3 formation by solid-solid diffusion of Ni and Al power, Ni2Al3 formation by liquid eutectic spreading on the surface of Ni power, and Ni2Al3 and NiAl formation by diffusion. Two endothermic peaks are respectively caused by primary eutectic contact melting and later A1 melting, and anti-peritectic reaction of NiAl3.