Hydrogen microalloying as a viable strategy for enhancing the glass-forming ability of Zr-based bulk metallic glasses

Granata, Davide; Fischer, Erwin; Löffler, Jörg F.

doi:10.1016/j.scriptamat.2015.03.005

Cited by 18 publications

(9 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thermal conductivity of hydrogen is 10 times greater than that of argon, so we suspect that the difference in GFA glass formation may have originated from the difference in the cooling rate. In a similar study, Granata et al [12,13] investigated Zr-based metallic glasses prepared under helium (which possesses the similar thermal conductivity as hydrogen), but observed quite different effects on glass-forming ability and plasticity. Apparently, the cooling rate is not the major factor.…”

Section: Resultsmentioning

confidence: 99%

Hydrogen-induced amorphization of Zr-Cu-Ni-Al alloy

Dong

Zhang

et al. 2017

China Foundry

View full text Add to dashboard Cite

Male, born in 1984, Doctor. He has been working in the field of advanced metallic materials with amorphous/glassy structure and their composites. In particular, his research focuses on developing new bulk metallic glasses used as hydrogen penetrating materials and hydrogen storage materials. T he limited glass-forming ability (GFA) of metallic glass restricts its application as a structural material. Although many laboratories have reported the development of large-sized (in many cases, centimeterplus) bulk metallic glasses (BMGs), the actual number of alloys suitable for commercial production is quite low [1] . It is of considerable practical significance to enhance the GFA of existing BMG-forming alloys. For these alloy systems, the nature and number of components and purity of elements are critical factors in terms of GFA and mechanical properties [2] . The GFA and properties of BMGs are also quite sensitive to the material's composition. Therefore, minor alloying additions play an important role in the glass formation, thermal stability, and comprehensive properties of BMGs [3] .Various elements have been employed to change the Abstract: Arc melting was utilized in this study to produce Zr 55 Cu 30 Ni 5 Al 10 alloys under mixed atmospheres with various ratios of high-purity hydrogen to argon. The influences of hydrogen addition on the solidification structure and glass-forming ability of Zr 55 Cu 30 Ni 5 Al 10 alloy were determined by examining microstructures in different parts of the cast ingots. The results showed that different degrees of crystallization structures were obtained in the ascast button ingots after arc melting in high-purity Ar, and the cross-sectional solidification morphology of arcmelted ingots was found to consist of crystals with varying from the bottom up. By contrast, there were completely amorphous structures in the middle and upper areas of the as-cast button ingots fabricated by adding 10% H 2 to the high-purity Ar atmosphere. A clear solidification interface was found between the crystal and glass in the ascast button ingots, which indicates that hydrogen addition can enhance the Zr 55 Cu 30 Ni 5 Al 10 alloy's glass-forming ability. The precise mechanism responsible for this was also investigated.

show abstract

Section: Resultsmentioning

confidence: 99%

Hydrogen-induced amorphization of Zr-Cu-Ni-Al alloy

Dong

Zhang

et al. 2017

China Foundry

View full text Add to dashboard Cite

show abstract

“…One is the extrinsic toughening by surface treatment, pre-deformation or developing a composite microstructure with external ductile phase dispersed within the glassy matrix [16][17][18][19][20][21][22][23][24] . Another is the intrinsic toughening by designing phase separation, increasing the Poisson s ratio or the amount of free volume in BMGs, adjusting the Young s modulus and so on [25][26][27][28][29] . In generally, the latter approach can be implemented in technique through tailoring composition, changing cooling rate, thermomechanical treatment, etc.…”

Section: Introductionmentioning

confidence: 99%

Plasticity Improvement of Zr-Based Bulk Metallic Glasses by Adjusting Oxygen Content and Cooling Rate

Lei

Yeung³

et al. 2017

Mater. Trans.

View full text Add to dashboard Cite

The poor plasticity of amorphous metal at room temperature has proved to be one of the biggest obstacles for its widespread application as structural components. In present study, the experimental samples were prepared by suction-casting and high vacuum die-casting with Zr 54.6 Ti 13.8 Cu 9.3 Ni 5.8 Be 13.5 Nb 3 (at. %) to discuss the effect of the oxygen content and cooling rate on the plasticity of amorphous metal respectively. The results indicate that dendrite with appropriate dimension and fraction can be obtained by adjusting oxygen content so as to improve the plasticity of metallic glasses. Likewise, the appropriate cooling rate even above the critical cooling rate can also be quite effective to make the brittle metallic glasses obtain high plasticity.

show abstract

“…Recently, minor doping with hydrogen has been found to simultaneously improve the glass-forming ability (GFA) and the compressive ductility of Zr-based BMGs [15][16][17]. Such processing-induced microalloying incorporates hydrogen directly into the glassy structure, resulting in a higher packing density, as illustrated by positron annihilation spectroscopy (PAS) [15], and increased local inhomogeneity [16].…”

Section: Introductionmentioning

confidence: 99%

“…Such processing-induced microalloying incorporates hydrogen directly into the glassy structure, resulting in a higher packing density, as illustrated by positron annihilation spectroscopy (PAS) [15], and increased local inhomogeneity [16]. This increased structural heterogeneity is thought to promote the multiplication of shear bands and accordingly enhance the attainable ductility [18].…”

Section: Introductionmentioning

confidence: 99%

“…However, the durability of the hydrogen-induced beneficial effects must be studied in greater detail because of the common incidence of high hydrogen diffusivity. In this paper we therefore investigate how hydrogen microalloying affects the plasticity of Pd 77.5 Si 16.5 Cu 6 [19,20] and Zr-rich Zr 64 Cu 22 Al 12 [16,21] BMGs. In this context we first investigate the solubility and diffusivity of hydrogen in both systems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation