Effect of natural aging on relaxation behavior and mechanical property of a La-based bulk metallic glass

Natural aging, which is the spontaneous temporal evolution of meta-stable systems, is a great task in amorphous materials. In this work, La₆₂Al₁₄(Cu_5/6Ag_1/6)₁₄(Ni_1/2Co_1/2)₁₀ BMGs with the same master alloy was prepared 8 years ago and at present. The effect of natural aging on the relaxation behavior and mechanical property of the La-based BMG was studied. Experimental results based on dynamic mechanical analysis and differential scanning calorimetry showed that natural aging for 8 years caused the atomic configuration to relax from a meta-stable state to a relatively more stable state, and the crystallization characteristic was also affected by natural aging. The results of compression testing indicated that the plasticity of the La-based BMG would be reduced, as a result of structural relaxation caused by natural aging.