Elevating the fracture toughness of Cu49Hf42Al9 bulk metallic glass: Effects of cooling rate and frozen-in excess volume

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	Elevating the fracture toughness of Cu49Hf42Al9 bulk metallic glass: Effects of cooling rate and frozen-in excess volume
	Z. D. Zhu; E. Ma; J. Xu
	2014
发表期刊	Intermetallics
ISSN	0966-9795
卷号	46 页码:164-172
摘要	A major challenge for the structural applications of bulk metallic glasses (BMGs) is to improve their fracture toughness. Here we demonstrate that by increasing the cooling rate during the casting of liquid Cu49Hf42Al9 into BMG, using a mixed argon and helium atmosphere, the notch toughness of the resultant BMG can be tripled relative to that obtained at slower cooling rates. The much elevated toughness is attributed to a ten-fold increase in the size of the plastic zone at crack tip, due to the proliferation of shear banding facilitated by enhanced propensity for shear transformations. The latter propensity is explained by the reduced shear modulus and microhardness, as well as increased enthalpy recovery, all of which are rooted in structural disorder as reflected by the lowered density and increased frozen-in excess volume. Such a structure-property correlation is systematically demonstrated by monitoring all these properties over a range of diameters of the as-cast BMG rods that correspond to cooling rate levels from 40 K/s to 10(3) K/s. (C) 2013 Elsevier Ltd. All rights reserved.
部门归属	[zhu, zhen-dong ; xu, jian] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [ma, evan] johns hopkins univ, dept mat sci & engn, baltimore, md 21218 usa. ; xu, j (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china. ; jianxu@imr.ac.cn
关键词	Glasses, Metallic Fracture Toughness Brittleness And Ductility Elastic Properties Ni-cu-be Structural Relaxation Plastic-deformation Residual-stresses Mechanical-behavior Supercooled Liquids Amorphous Alloy Transition Diffraction Hardness
URL	查看原文
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/72513
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. D. Zhu,E. Ma,J. Xu. Elevating the fracture toughness of Cu49Hf42Al9 bulk metallic glass: Effects of cooling rate and frozen-in excess volume[J]. Intermetallics,2014,46:164-172.
APA	Z. D. Zhu,E. Ma,&J. Xu.(2014).Elevating the fracture toughness of Cu49Hf42Al9 bulk metallic glass: Effects of cooling rate and frozen-in excess volume.Intermetallics,46,164-172.
MLA	Z. D. Zhu,et al."Elevating the fracture toughness of Cu49Hf42Al9 bulk metallic glass: Effects of cooling rate and frozen-in excess volume".Intermetallics 46(2014):164-172.