Growth kinetics of the sputtered Ni-30Cr-5Al alloy nanograins: Effects of Y addition and oxidation

作者：Huang, Zongxiang; Su, Chang; Xie, Yun; Peng, Xiao^*

来源：Surface and Coatings Technology, 2023, 459: 129360.

DOI：10.1016/j.surfcoat.2023.129360

• NiCrAl
• Nanocrystalline alloys
• Sputtering
• Grain growth
• Y effect

The grain growth of the sputtered Ni-30Cr-5Al and Ni-30Cr-5Al-1Y (wt%) nanocrystalline alloys during tem-perature rising to and isothermally holding at 1000 degrees C in Ar has been investigated by transmission electron microscope (TEM). The thermal-induced grain growth of the two alloys at 1000 degrees C follows a law of dn -d0n = kt but the Y presence results in an increase of n from 3.46 to 3.95. This is attributed to Y segregation at the alloy grain boundaries (GBs) and Y-rich phase precipitation, which retards the GB curvature-driven grain growth thermodynamically by a solute drag effect and kinetically by second-phase pinning effect, respectively. More-over, the Y-free alloy grains grow much faster in air than in Ar, because the surface oxidation in air generates additional tensile stresses in the alloy which facilitate the GB mobility. The Y-containing alloy nanograins remain similar in size during heating in air and in Ar, plausibly due to the formation of more Y-rich oxide particles which hinder the GB mobility through the Zener pinning effect.

• 单位
  南昌航空大学