不同GFA锆基非晶的内耗行为

Internal Friction of Zr-based Metallic Glasses with Different Glass Forming Ability

利用内耗法研究了5种不同GFA(非晶形成能力)的锆基非晶(分别为Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)、Zr_(55)Al_(10)Ni_5Cu_(30)、Zr_(45)Cu_(45)Ag_5Al_5、Zr_(65)Al_(7.5)Ni_(10)Cu1_(7.5)、Zr_(57)Ti_5Al_(10)Cu_(20)Ni_8的力学行为,探索了内耗与GFA之间的关系。内耗温度曲线结果表明,GFA越大,非晶试样所产生的内耗峰值越高,且通过计算过冷液相区的激活能与从内耗的物理意义相联系,提出了一个表征同种体系GFA的新参数—内耗峰峰值。此外根据内耗频率曲线考察了不同GFA的锆基非晶的力学弛豫行为,GFA越大,其在过冷液相区内原子失稳的数量越多,力学弛豫时间越短。

Five kinds of Zr based BMGs with different GFA（glass forming ability）, Zr（41.2）Ti（13.8）Cu（12.5）Ni（10）Be（22.5）、Zr（55）Al（10）Ni5Cu（30）、Zr（45）Cu（45）Ag5Al5、Zr（65）Al（7.5）Ni（10）Cu1（7.5）、Zr（57）Ti5Al（10）Cu（20）Ni8, were used to study the relationship between GFA and internal friction（IF）. By comparing the internal friction-temperature curves of different samples, it is found that the higher the GFA is, the higher the value of IF peak is. Compared with the activity energy evaluated during the supercooled liquid, the nature of internal friction shows the reason that the metallic glass with higher GFA has the higher internal friction. So a new criterion evaluating the GFA was proposed, i.e. internal friction peak. Besides, based on the internal friction-loading frequency curves of the five samples, the behavior of mechanical relaxation was discussed. It is shown that the higher GFA is, the more the instability atoms in the supercooled liquid are, and the shorter the time of mechanical relaxation is.