摘要
Glass-forming ability is a long-standing concern in the field of metallic glasses(MGs),which greatly limits their maximum casting size and extensive applications.In this work,we report an ultrasonic-assisted rapid cold welding of bulk MGs without using any additives.MGs with various compositions are welded together under a 20,000-Hz highfrequency ultrasonic vibration without losing their amorphous nature.The ultrasonic technology offers the advantages of rapid bonding(<1 s)at low temperature(near room temperature)and low stress(<1 MPa).According to the phenomenon observed in the experiment,the activated fresh atoms diffuse through the broken channel port under continuous rupture of the oxide layer,and the ultrasonic vibration accelerates the atomic-diffusion process.Finally,stable bonding of the MG interface is realized.This universal ultrasonic-assisted welding process can realize the composition design of dissimilar MGs as well as tuning of new materials with new performance.
玻璃形成能力是金属玻璃领域中长期存在的问题,它极大地限制了金属玻璃的最大铸造尺寸和广泛应用.在本研究中,我们报道了超声辅助快速冷焊接块体金属玻璃的方法.在不需要焊料的情况下,通过20,000赫兹的高频振动实现了不同组分金属玻璃的结合,并且保证了金属玻璃的非晶态特性.超声技术有低温低压快速焊接的优点,其中焊接温度接近室温,压强小于1 MPa,焊接时间小于1 s.根据观察到的现象,随着金属玻璃氧化层的不断破裂,金属玻璃被超声振动激活并通过破裂的氧化层扩散到基体中,同时超声振动加速了扩散的过程,最终实现金属玻璃界面的稳定结合.这种普适性的超声辅助焊接工艺可以实现金属玻璃的大块化,以及不同组分的非晶态复合材料与新性能的设计.
基金
supported by the Key Basic and Applied Research Program of Guangdong Province,China(2019B030302010)
the National Natural Science Foundation of China(51871157,51971150 and 51775351)
the Science and Technology Innovation Commission Shenzhen(JCYJ20170412111216258)
the National Key Research and Development Program of China(2018YFA0703605)
Shenzhen Basic Research Project(JCYJ20190808152409578).
