In Situ Crystallization Measurements on Fe-Zr Glasses Using an Automated High-Temperature Diffractometer with a Position Sensitive Detector

1986 ◽  
Vol 30 ◽  
pp. 483-491 ◽  
Author(s):  
G. Zorn ◽  
E. Hellstern ◽  
H. Göbel ◽  
L. Schultz
Keyword(s):  
Metallic Glasses ◽  
Elevated Temperatures ◽  
Composition Range ◽  
Amorphous State ◽  
Glass Forming ◽  
Metal Metal ◽  
In Situ Crystallization ◽  
Position Sensitive ◽  
Fast Quenching

Metallic glasses are mostly produced by fast quenching from a melt. The glass forming composition range in binary materials is thereby restricted to the area around eutectics. The production of metal-metal binary glasses in a much wider composition range is possible by employing a technique called 'mechanical alloying'. Using this technique the metallic class is produced as a powder which can be manufactured into any shape to make use of the properties the material exhibits in the amorphous state. During compacting, and also in some applications of the finished product, the glass has to endure elevated temperatures which might cause devitrification. Since this crystallization of a metallic glass usually results in the loss of properties essential for a certain application it is necessary to investigate this crystallization behaviour and thus receive information about a material's prospective performance in a particular application.

TEM Studies of Shear Bands in a Bulk Metallic Glass Based Composite

2001 ◽  
Vol 7 (S2) ◽  
pp. 1120-1121
Author(s):  
E. Pekarskaya ◽  
C.P. Kim ◽  
W.L. Johnson
Keyword(s):  
Metallic Glasses ◽  
Shear Bands ◽  
High Yield ◽  
In Situ Tem ◽  
Two Phase ◽  
University Of Illinois ◽  
Glass Forming ◽  
The University ◽  
Very High

In 1980’s the discovery of multicomponent systems with exceptional glass forming ability enabled the synthesis of metallic glasses at relatively low cooling rates, 10−1 — 102 K/s and at a larger thicknesses. Bulk metallic glasses normally have very high yield stress, σy = 0.02 · Y (Y is Young’s modulus), high elastic limit of about 2%, but fail with very little global plasticity, typically along a localized shear band at a 45 degree angle with respect to the applied stress.The material studied in the present work is a two-phase Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 alloy,prepared by in-situ processing. The alloy consists of amorphous and crystalline phases. In-situ TEM straining (tensile) experiments were performed at room temperature in JEOL 4000EX operating at 300kV. The experiments were carried out in the Center for Microanalysis of Materials in the University of Illinois at Urbana-Champaign. The goal of the study was to understand the deformation mechanisms of such composite material.

Nanoindentation in Metallic Glasses with Different Plasticity

2015 ◽  
Vol 662 ◽  
pp. 19-22
Author(s):  
Kornel Csach ◽  
Jozef Miškuf ◽  
Alena Juríková ◽  
Maria Hurakova ◽  
Václav Ocelík ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Metallic Glasses ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Thermal Stability Of

Nanoindentation and thermomechanical experiments on three types of metallic glasses with different glass forming ability were carried out. The nanoindentation behaviour at room temperature was associated with the creep at elevated temperatures. Different discontinuity populations and their shape observed on the nanoindentation loading curves were compared with morphology of plastic deformed indent regions. The influence of the differences in thermal stability of studied alloys on the nanoindentation in these alloys were studied as well.

Deformation-Induced Nanocrystallization in Al-Rich Metallic Glasses

2006 ◽  
Vol 114 ◽  
pp. 123-132 ◽  
Author(s):  
Nancy Boucharat ◽  
Rainer J. Hebert ◽  
Harald Rösner ◽  
Gerhard Wilde
Keyword(s):  
Metallic Glasses ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
In Situ Tem ◽  
Number Density ◽  
High Number Density ◽  
Glass Forming ◽  
Processing Strategies ◽  
Improved Performance

Deformation-induced nanocrystallization has been investigated in a marginally Al88Y7Fe5 glass forming alloy. Conventional calorimetry and microstructural analyses of materials that have been subjected to high pressure torsion straining (HPT) at room temperature indicate the development of an extremely high number density of small Al nanocrystals. The nanocrystals appear to be distributed homogeneously throughout the sample without any evidence of strong coarsening. Moreover, the comparison between nanocrystallization caused by the application of either HPT, cold-rolling or in-situ TEM tensile straining yielded the identification of the probable mechanisms underlying the formation of nanocrystals. These results form the basis for the development of advanced processing strategies for producing new nanostructures with high nanocrystal number densities which allow increased stability and improved performance.

In situ crystallization of Zirconium-based bulk metallic glasses

2000 ◽  
Vol 276-278 ◽  
pp. 905-906 ◽  
Author(s):  
J.L Soubeyroux ◽  
J.M Pelletier ◽  
R Perrier de la Bâthie
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
In Situ Crystallization

Understanding the Glass-forming Ability of Cu50Zr50 Alloys in Terms of a Metastable Eutectic

2005 ◽  
Vol 20 (9) ◽  
pp. 2307-2313 ◽  
Author(s):  
W.H. Wang ◽  
J.J. Lewandowski ◽  
A.L. Greer
Keyword(s):  
Metallic Glasses ◽  
Glass Formation ◽  
Composition Range ◽  
Intermetallic Phase ◽  
Glass Forming Ability ◽  
Copper Mold ◽  
Wide Composition Range ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting

Interest in finding binary alloys that can form bulk metallic glasses has stimulated recent work on the Cu–Zr system, which is known to show glass formation over a wide composition range. This work focuses on copper mold casting of Cu50Zr50 (at.%), and it is shown that fully amorphous rods up to 2-mm diameter can be obtained. The primary intermetallic phase competing with glass formation on cooling is identified, and the glass-forming ability is interpreted in terms of a metastable eutectic involving this phase. Minor additions of aluminum increase the glass-forming ability: with addition of 4 at.% Al to Cu50Zr50, rods of at least 5-mm diameter can be cast fully amorphous. The improvement of glass-forming ability is related to suppression of the primary intermetallic phase.

An experimental investigation on the notch toughness of Cu-Zr-based bulk metallic glasses with in-situ crystallization

2017 ◽  
Vol 469 ◽  
pp. 70-78 ◽  
Author(s):  
Laura M. Andersen ◽  
Sabine Faulhaber ◽  
Tyler Harrington ◽  
Douglas C. Hofmann ◽  
Huikai Cheng ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Notch Toughness ◽  
In Situ Crystallization

scholarly journals Glass Formation Range of Mg-Based Bulk Metallic Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 2018-2025 ◽  
Author(s):  
Jean Louis Soubeyroux ◽  
Stéphane Gorsse ◽  
G. Orveillon
Keyword(s):  
Metallic Glasses ◽  
Composition Range ◽  
Driving Forces ◽  
Critical Diameter ◽  
Ternary Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Mould Casting ◽  
Formation Range

New bulk metallic glasses (BMG) have been synthesized in the Mg-Cu-RE systems (RE= Y, Gd) with high critical diameter. In order to determine the glass forming range of these ternary systems, the calculation of the onset of driving forces (ODF) has been performed and has shown a large composition range for BMG formation. The synthesis of particular compositions in this domain has shown that all the produced alloys present a high glass forming ability (GFA) measured by DSC experiments. The ODF model, synthesized alloys by mould casting, characterization by X-ray diffraction and DSC techniques are presented.

Enhancing bulk metallic glass formation in Ni–Nb–Sn-based alloys via substitutional alloying with Co and Hf

2008 ◽  
Vol 23 (3) ◽  
pp. 688-699 ◽  
Author(s):  
Li Zhang ◽  
Mu-Jin Zhuo ◽  
Jian Xu
Keyword(s):  
Metallic Glass ◽  
Ternary System ◽  
Metallic Glasses ◽  
Glass Formation ◽  
Composition Range ◽  
Glass Forming Ability ◽  
Partial Substitution ◽  
Wide Composition Range ◽  
Positive Effects ◽  
Glass Forming

Bulk metallic glasses have been formed over a fairly wide composition range (54–62 at.% Ni, 32–36 at.% Nb, and 3–11 at.% Sn) in the Ni–Nb–Sn ternary system. Partial substitution of Co for Ni and Hf for Nb improves the glass-forming ability, eventually leading to 4 mm glassy rods at the Ni56Co3Nb28Hf8Sn5 composition. The positive effects of these alloying elements have been explained based on a systematic monitoring of the amount and morphology of the competing crystalline phases as a function of the Co and Hf contents.

Sign in / Sign up

Export Citation Format

Share Document