【摘要】 在室温条件下对铸态Zr52Cu23Al14.5Ni10.5大块非晶合金进行5 h超声振动处理,通过X射线衍射(XRD)、高分辨透射电镜(HRTEM)、差示扫描量热分析(DSC)以及纳米压痕测试,研究长时间超声处理对大块Zr基非晶合金结构与显微力学行为的影响。结果表明,经过5 h超声振动处理后,Zr基非晶合金仍保留非晶态结构,没有发生晶化;超声振动对大块非晶合金的热力学特征温度如玻璃化转变温度(Tg)、晶化开始温度(Tx)以及晶化峰值温度(Tp)的影响都不大,但可诱导结构弛豫,使其自由体积明显减少;相比铸态合金,超声处理后的合金,其纳米压痕实验的载荷—位移曲线上的锯齿流变现象明显减少,显微硬度和弹性模量均明显提高,分别从铸态的5.7 GPa和102 GPa提高到6.5 GPa和122 GPa。表明超声振动处理是一种室温调控大块非晶合金力学性能的有效手段。更多还原

【Abstract】 The as-cast Zr52Cu23Al14.5Ni10.5 bulk metallic glass(BMG) was ultrasonic treated for 5 h at room temperature.The effect of ultrasonic treatment on the structure and micromechanical behaviors of the Zr52Cu23Al14.5Ni10.5 BMG was investigated by XRD,TEM,DSC and nanoindentation method.The results show that the amorphous structure are retained and typical thermodynamic parameters,such as glass transition temperature(Tg),onset crystallization temperature(Tx) and crystallization peak temperature(Tp),do not change for the Zr-based BMG after ultrasonic treatment for 5 h.However,ultrasonic vibration can result in the structural relaxation and the decrease of the free volume in the Zr-based BMG.This makes the microhardness and elastic modulus of the sample after ultrasonic treatment(HIT=6.5 GPa,EIT=122 GPa) be higher than those of the as-cast one(HIT=5.7 GPa,EIT=102 GPa),and the pop-in events in the F-h curve after ultrasonic treatment become fewer.This also means that ultrasonic treatment can be regarded as an effective method to control the micromechanical properties of BMGs.更多还原