Special Issue "Amorphous Alloys and Related Transitions"

A special issue of Metals (ISSN 2075-4701).

Deadline for manuscript submissions: closed (30 November 2016)

Special Issue Editor

Guest Editor
Prof. Ralph E. Napolitano

Department of Materials Science and Engineering, Iowa State University, 528 Bissell Road, Ames, IA 50011-1096, USA
Website | E-Mail
Interests: alloy solidification; alloy thermodynamics; metallic glass; diffusional phase transformations; additive manufacturing; computational modeling

Special Issue Information

Dear Colleagues,

Non-crystalline metallic solids, also known as amorphous alloys, represent an interesting class of materials in terms of both fundamental behavior and potential applications. On rapid cooling from the liquid state, metallic alloys may develop various forms of short- and medium-range order that are non-crystalline in nature, yet may provide some structural and/or chemical connection to stable or metastable crystalline phases. In this way, liquid process pathways that include amorphous phases, non-crystalline structural motifs, and the kinetic arrest associated with glassy behavior may be exploited to realize novel far-from-equilibrium structures that are difficult to otherwise achieve.

Experimental and computational research in the field of amorphous alloys has brought about considerable advancements related to fundamental physical properties, glass-forming behavior, processing and control of phase transformations, thermodynamic and kinetic properties, mechanical behavior, and many types of potential applications. Indeed, the field of amorphous alloys is a rich and fertile ground for the discovery of new materials with unusual properties and novel processing routes to take advantage of far-from-equilibrium transformations.

With this announcement, I would like to invite for inclusion in a Special Issue on “Amorphous Alloys” original research papers and review articles focusing on topics, such as fundamental structure and behavior, modeling and simulation, processing and phase transformations, and properties/applications of amorphous metallic alloys.

Prof. Dr. Ralph E. Napolitano
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Metals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Amorphous alloys
  • Non-crystalline alloys
  • Metallic glass
  • Undercooled liquids
  • Glass forming metals
  • Rapid solidification

Published Papers (8 papers)

View options order results:
result details:
Displaying articles 1-8
Export citation of selected articles as:

Research

Open AccessArticle Weibull Statistical Reliability Analysis of Mechanical and Magnetic Properties of FeCuNbxSiB Amorphous Fibers
Metals 2017, 7(3), 76; doi:10.3390/met7030076
Received: 16 December 2016 / Revised: 1 February 2017 / Accepted: 17 February 2017 / Published: 28 February 2017
PDF Full-text (9090 KB) | HTML Full-text | XML Full-text
Abstract
Glass-coated Fe76.5−xCu1NbxSi13.5B9 (x = 0, 1, 2, 3, 3.5) fibers were successfully fabricated by a modified Taylor method. The fibers showed circular morphology and smooth surface with different diameters. The mechanical properties
[...] Read more.
Glass-coated Fe76.5−xCu1NbxSi13.5B9 (x = 0, 1, 2, 3, 3.5) fibers were successfully fabricated by a modified Taylor method. The fibers showed circular morphology and smooth surface with different diameters. The mechanical properties of the fibers were evaluated and the Weibull statistical analysis has been introduced to characterize the strength reliability of the fibers, with the modulus m of the amorphous fibers reaching above 20. The magnetic properties were also studied. Lower coercivity was found for the fibers with amorphous, nanocrystalline, and microcrystalline structures rather than that for the coarse crystalline ones. The glass-coated FeCuNbSiB amorphous fibers have excellent comprehensive performance compared with the other kind of fibers. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Open AccessArticle Tensile Strength Reliability Analysis of Cu48Zr48Al4 Amorphous Microwires
Metals 2016, 6(12), 296; doi:10.3390/met6120296
Received: 6 September 2016 / Revised: 6 November 2016 / Accepted: 17 November 2016 / Published: 24 November 2016
Cited by 2 | PDF Full-text (3003 KB) | HTML Full-text | XML Full-text
Abstract
Uniform Cu48Zr48Al4 amorphous microwires with a high surface quality are fabricated by a melt extraction technique. The mechanical property of microwires is evaluated via tensile tests. To estimate the strength scattering, statistical analysis of fracture strengths is conducted
[...] Read more.
Uniform Cu48Zr48Al4 amorphous microwires with a high surface quality are fabricated by a melt extraction technique. The mechanical property of microwires is evaluated via tensile tests. To estimate the strength scattering, statistical analysis of fracture strengths is conducted using logarithmic normal distribution, and two- and three-parameter Weibull analysis, severally. The results show that the tensile strengths of Cu48Zr48Al4 amorphous microwires range from 1724 to 1937 MPa with the arithmetical average value of 1836 MPa, and the arithmetical standard deviation of 56.4 MPa. The geometric mean of fracture strength is 1840 MPa using logarithmic normal distribution statistical analysis. Using two- and three-parameter Weibull analysis, the Weibull modulus and fracture threshold value are respectively calculated for 34.8 and 1483 MPa, which shows the excellent tensile mechanical properties with a high predictability of Cu48Zr48Al4 amorphous microwires and further indicates the great potential of application. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Open AccessArticle The Co-B Amorphous Alloy: A High Capacity Anode Material for an Alkaline Rechargeable Battery
Metals 2016, 6(11), 269; doi:10.3390/met6110269
Received: 29 August 2016 / Revised: 17 October 2016 / Accepted: 3 November 2016 / Published: 7 November 2016
PDF Full-text (1593 KB) | HTML Full-text | XML Full-text
Abstract
The Co-B amorphous alloys were prepared via a chemical reduction method by sodium borohydride, using three different cobalt salts (CoCl2·6H2O, CoSO4·7H2O, and Co(NO3)2·6H2O) as sources of cobalt. As anode
[...] Read more.
The Co-B amorphous alloys were prepared via a chemical reduction method by sodium borohydride, using three different cobalt salts (CoCl2·6H2O, CoSO4·7H2O, and Co(NO3)2·6H2O) as sources of cobalt. As anode materials in alkaline rechargeable batteries, the Co-B alloy prepared from CoCl2·6H2O has a maximum specific discharge capacity of 844.6 mAh/g, and 306.4 mAh/g is retained even after 100 cycles at a discharge current of 100 mA/g. When Co(NO3)2·6H2O is used as a raw material, the formation of Co3(BO3)2 worsens the electrochemical properties of the sample, i.e., a maximum capacity of only 367.0 mAh/g. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Open AccessArticle Short-to-Medium-Range Order and Atomic Packing in Zr48Cu36Ag8Al8 Bulk Metallic Glass
Metals 2016, 6(10), 240; doi:10.3390/met6100240
Received: 13 May 2016 / Revised: 19 September 2016 / Accepted: 19 September 2016 / Published: 12 October 2016
Cited by 1 | PDF Full-text (2465 KB) | HTML Full-text | XML Full-text
Abstract
Due to its excellent glass-forming ability (GFA), the Zr48Cu36Al8Ag8 bulk metallic glass (BMG) is of great importance in glass transition investigations and new materials development. However, due to the lack of detailed structural information, the local
[...] Read more.
Due to its excellent glass-forming ability (GFA), the Zr48Cu36Al8Ag8 bulk metallic glass (BMG) is of great importance in glass transition investigations and new materials development. However, due to the lack of detailed structural information, the local structure and atomic packing of this alloy is still unknown. In this work, synchrotron measurement and reverse Monte Carlo simulation are performed on the atomic configuration of a Zr-based bulk metallic glass. The local structure is characterized in terms of bond pairs and Voronoi tessellation. It is found that there are mainly two types of bond pairs in the configuration, as the body-centered cubic (bcc)-type and icosahedral (ico)-type bond pairs. On the other hand, the main polyhedra in the configuration are icosahedra and the bcc structure. That is, the bcc-type bond pairs, together with the ico-type bond pairs, form the bcc polyhedra, introducing the distortion in bcc clusters in short range. However, in the medium range, the atoms formed linear or planar structures, other than the tridimensional clusters. That is, the medium-range order in glass is of 1D or 2D structure, suggesting the imperfect ordered packing feature. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Open AccessArticle The Evolution of Microstructures and the Properties of Bulk Metallic Glass with Consubstantial Composition Laser Welding
Metals 2016, 6(10), 233; doi:10.3390/met6100233
Received: 20 July 2016 / Revised: 29 August 2016 / Accepted: 13 September 2016 / Published: 29 September 2016
Cited by 2 | PDF Full-text (9849 KB) | HTML Full-text | XML Full-text
Abstract
A Zr55Cu30Ni5Al10 plate-like bulk metallic glass (BMG) was prepared using copper mold suction casting. Additionally, alloy powders with the same nominal composition were synthesized. The alloy powders were welded or melted to the cleaned surface of
[...] Read more.
A Zr55Cu30Ni5Al10 plate-like bulk metallic glass (BMG) was prepared using copper mold suction casting. Additionally, alloy powders with the same nominal composition were synthesized. The alloy powders were welded or melted to the cleaned surface of the BMG with a laser beam acceleration voltage of 60 kV, a beam current range from 60 to 100 mA, a welding speed of 60 mm/s, as well as an impulse width of 3.0 ms. The effect of consubstantial composition welding on the microstructures and properties was investigated. The molten and subsequently solidified metallic mixtures remain an amorphous structure, but the enthalpy of the welded or melted position varies due to the combination of the micro-structural relaxation and nano-crystals precipitated during the energy inputs. The surface layers of the BMG can be significantly intensified after welding processes; however, the heat-affected zones (HAZs) exhibit a slight degradation in mechanical properties with respect to the BMG matrix. This study has important reference value for specialists working on the promotion of applications of BMGs. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Open AccessArticle Glass Forming Ability and Corrosion Resistance of Zr-Cu-Ni-Al-Ag Bulk Metallic Glass
Metals 2016, 6(10), 230; doi:10.3390/met6100230
Received: 13 July 2016 / Revised: 20 September 2016 / Accepted: 20 September 2016 / Published: 24 September 2016
PDF Full-text (16317 KB) | HTML Full-text | XML Full-text
Abstract
Zr70−xCu12.5Ni10Al7.5Agx (x = 0–10) bulk metallic glasses (BMGs) have been prepared by copper mold casting. The glass-forming ability (GFA) and corrosion behavior of Zr-based BMGs have been investigated. It is found that
[...] Read more.
Zr70−xCu12.5Ni10Al7.5Agx (x = 0–10) bulk metallic glasses (BMGs) have been prepared by copper mold casting. The glass-forming ability (GFA) and corrosion behavior of Zr-based BMGs have been investigated. It is found that the GFA of Zr-based BMGs first increases and then decreases with the increase of the Ag content, and the best glass former is Zr65Cu12.5Ni10Al7.5Ag5 with the maximum thickness of the glass phase region of 4.3 mm. The corrosion resistance is, however, found to be worsened with the increase of the Ag content. The mechanisms for the enhancement of GFA and the deterioration of corrosion resistance in the alloys are discussed. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Open AccessArticle Numerical Modeling of Cyclic Deformation in Bulk Metallic Glasses
Metals 2016, 6(9), 217; doi:10.3390/met6090217
Received: 24 July 2016 / Revised: 12 August 2016 / Accepted: 27 August 2016 / Published: 7 September 2016
Cited by 1 | PDF Full-text (6029 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a systematic numerical simulation was performed to elucidate the damage mechanisms in bulk metallic glasses (BMGs) subjected to the tension-compression cyclic loading, and then the relation between fatigue life, applied strain, and cycling frequency was therefore presented. The free volume
[...] Read more.
In this paper, a systematic numerical simulation was performed to elucidate the damage mechanisms in bulk metallic glasses (BMGs) subjected to the tension-compression cyclic loading, and then the relation between fatigue life, applied strain, and cycling frequency was therefore presented. The free volume was selected as an internal state variable to depict the shear-band nucleation, growth, and coalescence with the help of free volume theory, which was incorporated into the ABAQUS code via a user material subroutine UMAT. Under cyclic loading, the shear banding initiation mainly stems from the microstructure inhomogeneity in BMGs and, further, the effect of applied strain amplitude and cycling frequency was discussed. The present simulations will shed some light on the fatigue damage mechanisms and fatigue life evaluation of BMG structures. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Open AccessArticle The Effect of Ag Addition on the Enhancement of the Thermal and Mechanical Properties of CuZrAl Bulk Metallic Glasses
Metals 2016, 6(9), 216; doi:10.3390/met6090216
Received: 3 July 2016 / Revised: 29 August 2016 / Accepted: 1 September 2016 / Published: 7 September 2016
PDF Full-text (12800 KB) | HTML Full-text | XML Full-text
Abstract
In this study, the thermal and mechanical properties of Cu50−xZr43Al7Agx (x = 0, 3, 4, 5, 6) bulk metallic glasses (BMGs) are investigated by using an X-ray diffractometer (XRD), a differential scanning calorimeter (DSC),
[...] Read more.
In this study, the thermal and mechanical properties of Cu50−xZr43Al7Agx (x = 0, 3, 4, 5, 6) bulk metallic glasses (BMGs) are investigated by using an X-ray diffractometer (XRD), a differential scanning calorimeter (DSC), differential thermal analysis (DTA), a Vickers hardness tester, a material test system (MTS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Cu50−xZr43Al7Agx (x = 0, 3, 4, 5, 6) BMGs were made by arc-melting and an injection casting process. The results revealed that the glass transition temperature (Tg) and the crystallization temperature (Tx) of CuZrAl alloy decreased with the Ag addition. Hence, the supercooled liquid region and γ of Cu45Zr43Al7Ag5 alloy increased to 76 K and 0.42, respectively. The thermal stability and glass forming ability of CuZrAlAg BMG alloys were enhanced by the microalloyed Ag content. The room temperature compressive fracture strength and strain measured of Cu47Zr43Al7Ag3 were about 2200 MPa and 2.1%, respectively. The distribution of vein patterns and the formation of nanocrystalline phases on the fracture surface of Cu47Zr43Al7Ag3 alloy can be observed by SEM and TEM to be significant, indicating a typical ductile fracture behavior and an improved plasticity of alloys with the addition of microalloyed Ag from 0 to 6 atom %. Full article
(This article belongs to the Special Issue Amorphous Alloys and Related Transitions)
Figures

Figure 1

Back to Top