Shear-accelerated crystallization of glass-forming metallic liquids in high-pressure die casting  

作　　者：L.H.Liu W.J.Gao X.S.Huang T.Zhang Z.Y.Liu C.Yang W.W.Zhang W.R.Li L.Li P.J.Li 

机构地区：[1]National Engineering Research Center of Near-net-shape Forming for Metallic Materials,South China University of Technology,Guangzhou,510640,China [2]Department of Mechanical Engineering,Tsinghua University,Beijing,100084,China [3]Institute of Eontech New Materials Co.,Ltd.,Dongguan,523662,China [4]Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering,College of Mechatronics and Control Engineering,Shenzhen University,Shenzhen,518060,China

出　　处：《Journal of Materials Science & Technology》2022年第22期146-157,共12页材料科学技术（英文版）

基　　金：L.H.Liu would like to thank the financial support from the National Natural Science Foundation of China(No.52001123);the China Postdoctoral Science Foundation(Nos.2019TQ0099 and 2019M662908);Guangdong Basic and the Applied Basic Research Foundation(No.2019A1515110215);the Foundation for Distinguished Young Talents in Higher Education of Guangdong(No.2019KQNCX003);the Fundamental Research Funds for the Central Universities(No.2020ZYGXZR030);the Open Fund of National Engineering Research Center of Near-net-shape Forming for Metallic Materials(No.2019003);C.Yang would like to thank the financial support from the Key Basic and Applied Research Program of Guangdong Province(No.2019B030302010);the National Natural Science Foundation of China(No.51971149).

摘　　要：As one of the most important forming technologies for industrial bulk metallic glass (BMG) parts withcomplex shapes, high-pressure die casting (HPDC) can fill a die cavity with a glass-forming metallic liquidin milliseconds. However, to our knowledge, the correlation between flow and crystallization behavior inthe HPDC process has never been established. In this study, we report on the solidification behavior ofZr_(55)Cu_(30)Ni_(5)Al_(10) glass forming liquid under various flow rates. Surprisingly, the resulting alloys display adecreasing content of amorphous phase with increase of flow rate, i.e. increase of cooling rate, suggestingthat crystallization kinetics of glass-forming metallic liquids in the HPDC process is strongly dependenton the flow field. Analysis reveals that the accelerated crystallization behavior is mainly ascribed to therapid increase in viscosity with a decreasing temperature as well as to the huge shear effect in the glassforming liquid at the end stage of the filling process when the temperature is close to the glass-transitionpoint;this results in a transition from diffusion- to advection-dominated transport. The current investigation suggests that flow-related crystallization must be considered to assess the intrinsic glass-formingability of BMGs produced via HPDC. The obtained results will not only improve the understanding ofcrystallization dynamics but also promote the high-quality production and large-scale application of BMGparts.

关 键 词：CRYSTALLIZATION SHEAR Supercooled liquid High pressure die casting 

分 类 号：TG139.8[一般工业技术—材料科学与工程]