高压热处理调节FeP金属玻璃空化行为

High pressure heat treatment tuning cavitation behavior in FeP metallic glass

脆性金属玻璃的空化现象可追溯其本征的高原子密度涨落.有目的地调节金属玻璃内部结构以抑制其空化行为一直是被关注的问题.本文通过分子动力学模拟研究了高压热处理对脆性Fe_(80)P_(20)金属玻璃空化行为的影响.高压热处理可诱导Fe_(80)P_(20)金属玻璃发生年轻化,有效抑制空化的发生.伴随压力和温度的增加,Fe_(80)P_(20)金属玻璃的空间异质性逐渐减小,同时磷原子的分布变得相对均匀.分析表明,高压热处理可诱导Fe_(80)P_(20)金属玻璃局部原子结构从“类液态”转变为“类固态”,致使空化需要更大的外加应力诱发.上述结果为理解金属玻璃的空间异质性和空化行为之间的关联规律提供了新的思路.

The origin of cavitation in brittle metallic glasses(MGs)is traced to the high degree of atomic density fluctuations.Purposely tuning the inherent structure to suppress cavitation has been a longstanding concern.Here we investigate the effect of high pressure heat treatment(HPHT)on the cavitation performance of a brittle Fe_(80)P_(20)MG through molecular dynamics(MD)simulations.We found that HPHT can induce rejuvenation and effectively suppress cavitation.The spatial heterogeneity reduces with the applied pressure and temperature,resulting in a relatively uniform distribution of P atoms.Our analysis demonstrates that the local atomic structure can be excited from a“liquid-like”state to a“solid-like”one by HPHT,where larger stress is required to initiate cavitation.This work provides new insight into the understanding of the relationship between spatial heterogeneity and cavitation behavior of MGs.