Activation energy for formation of nickel-aluminide thin film on nanocrystalline and microcrystalline nickel

作者：Rashidi A M^*

来源：Vacuum, 2013, 95: 35-42.

DOI：10.1016/j.vacuum.2013.02.006

• Activation energy
• Nanocrystalline nickel
• Nickel aluminide
• Thin film

In this paper, activation energy and time needed for formation of Al3Ni2 thin film with thickness of similar to 1 mu m on nanocrystalline (NC) nickel was investigated and compared with microcrystalline (MC) nickel. NC and MC samples were prepared by electrodeposition and annealing, respectively. The samples were aluminized by pack cementation method in the temperature range of 475-600 degrees C. The surface morphology and cross section of coated specimens were characterized by means of optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was observed that the time needed for formation of Al3Ni2 thin film on NC samples was shorter than that for MC specimens at all investigated temperatures. In addition, for both, time needed for formation of the thin film was decreased by increasing temperature according to exp (Q/RT). It was found that activation energy for formation of the thin film on NC samples was 35% lower than that for MC specimens. Activation energy for formation of thin film of Al3Ni2 were similar to 50% and similar to 120% lower than the activation energy for growth of thick layer of aluminide coating on MC and NC nickel, respectively.

• 出版日期2013-9