Thermally grown oxide formation on Ni2Al3 aluminide coating: The effect of nanocrystalline nickel film on oxide scale adhesion

The Ni2Al3 coatings were prepared by aluminizing with and without nanocrystalline (NC) Ni film using the pack cementation process for 5 hat 620 degrees C. After oxidation at 900 degrees C, the results demonstrate that the alumina formed on two Ni2Al3 coatings composed of O-Al2O3 on the basis of investigations of scanning electron microscopy (SEM), x-ray diffraction (XRD) and photo-stimulated luminescence spectroscopy (PSLS). The transmission electron microscopy (TEM) investigations combined with the electron diffraction pattern revealed that a small grain of alpha-Al2O3 nucleated on the Ni2Al3 coating with Ni film at the alumina scale/coating interface. Moreover, the Ni2Al3 coating with Ni film, in comparison to Ni2Al3 coating without Ni film control the size and density of the cavities formation at the scale/coating interface resulted in better adhesion of the alumina scale on aluminide.

Automated summary

The study found that the addition of nanocrystalline nickel film in the Ni2Al3 coatings prepared by pack cementation process can effectively control the particle formation during oxidation, leading to improved adhesion between the alumina scale and aluminide.