3 MeV Au ions were used to irradiate Hastelloy-N and Ni₆₀Nb₄₀ amorphous alloy, and total doses were 2.3×10¹⁵ cm^–2 and 5×10¹⁶ cm^–2. X-ray Diffraction results presented that Ni₆₀Nb₄₀ amorphous alloy showed good stability in crystal state, but Hastelloy-N had apparent strain increment after irradiation. Nano-Indenter test found that softening of Ni₆₀Nb₄₀ amorphous alloy and hardening of Hastelloy-N were mainly caused by atom displacement damage. Through measuring step heigh created by half-shielding irradiation with an Atomic Force Micoscope, the authors found that the irradiation swelling of both materials were approximate. Scan Electron Micoscope observation showed that the critical dose of Ni60Nb40 amorphous alloy surface viscous flow induced by 3 MeV Au ions was larger than 2.3×10¹⁵ cm^–2. The surface viscous flow critical dose was not uniform, which may be caused by surface stress induced by mechanical polishing. Ni₆₀Nb₄₀ amorphous alloy should be potential to be protective coating against corrosion and irradiation damage, for its self-healing of surface defects through viscous flow mechanism.