scholarly journals Thermal Analysis by Means of Differential Scanning Calorimetry of the Characteristic Thermodynamic Temperatures of a Cu-Zr-Al Bulk Metallic Glass

2022 ◽  
Vol 18 (1) ◽  
pp. 71-80
Author(s):  
Yanhong Li ◽  
Bing Li ◽  
Xinhui Fan ◽  
Ke Yang ◽  
Xin Wang
2007 ◽  
Vol 1048 ◽  
Author(s):  
Jinwoo Hwang ◽  
Hongbo Cao ◽  
Paul M. Voyles

AbstractWe investigated the influence of annealing on the nanometer-scale medium-range order in Zr54Cu38Al8 bulk metallic glass using fluctuation electron microscopy. Fluctuation microscopy experiments probing structure at a length scale of 1 nm show that the as-cast Zr bulk metallic glass contains significant medium range order. That structure is unchanged by annealing at 87% of the glass transition temperature for 24 hours, although that anneal does significantly change the differential scanning calorimetry trace.


2003 ◽  
Vol 806 ◽  
Author(s):  
R. Raghavan ◽  
U. Ramamurty ◽  
J. Basu ◽  
S. Ranganathan ◽  
N. Nishiyama

ABSTRACTThe stability of a Pd40Cu30Ni10P20 bulk metallic glass (BMG) against structural relaxation is investigated by isothermal and isochronal annealing heat treatments below and above its glass transition temperature, Tg, for varying periods. Differential scanning calorimetry (DSC) of the annealed samples shows an excess endotherm at Tg, irrespective of the annealing temperature. This recovery peak evolves exponentially with annealing time and is due to the destruction of anneal-induced compositional short range ordering. The alloy exhibits a high resistance to crystallization on annealing below Tg and complex Pd- and Ni-phosphides evolve on annealing above Tg.


2014 ◽  
Vol 910 ◽  
pp. 48-52 ◽  
Author(s):  
Jian Sheng Gu ◽  
Hui Feng Bo

Structural relaxation through isothermal annealing below the glass transition temperature was conducted on a Zr64.13Cu15.75Ni10.12Al10bulk metallic glass. Differential scanning calorimetry was used to quantify enthalpy differences between the as-cast and relaxed samples, which were then related to average free volume differences. The influence of structural relaxation on plasticity was examined. While the free volume decreasement can be clearly observed between the as-cast and relaxed samples, structural relaxation is not accompanied by severe embrittlement.


2002 ◽  
Vol 16 (03) ◽  
pp. 87-92 ◽  
Author(s):  
CZ. GÓRECKI ◽  
T. GÓRECKI ◽  
S. SZYMURA

Surface and volume crystallization of amorphous, melt-quenched (Ni50Zr50)99.9P0.1 alloy has been investigated by measurements of the temperature dependencies of the intensity of photostimulated exoelectron emission (EEE) and by differential scanning calorimetry (DSC). A comparison of these dependencies enables one to assess the tendency of the investigated materials to premature surface crystallization. For the (Ni50Zr50)99.9P0.1 alloy the surface crystallization occurs at temperatures distinctly lower than that for the crystallization in bulk. The activation energy for the surface crystallization, determined by the Ozawa method, i.e. from the shift of EEE peak corresponding to the surface crystallization on changing the heating rate, is also much lower than that for the volume crystallization.


2004 ◽  
Vol 19 (5) ◽  
pp. 1307-1310 ◽  
Author(s):  
L. Xia ◽  
M.B. Tang ◽  
H. Xu ◽  
M.X. Pan ◽  
D.Q. Zhao ◽  
...  

A hard magnetic Nd50Al15Fe15Co20 bulk metallic glass (BMG) was prepared in the shape of a rod up to 3 mm in diameter by suction casting. The glass transition and crystallization behaviors as well as their kinetic nature have been studied. In contrast to the previously reported hard magnetic Nd–Al–Fe–Co BMGs, Nd50Al15Fe15Co20 as-cast rod exhibits a distinct glass transition and multistep crystallization behaviors in the differential scanning calorimetry traces and lower coercivity. The BMG provides an ideal model for the investigation of glass transition and crystallization of hard magnetic Nd–Al–Fe–Co glass-forming alloys.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Fatahah Asyqin Zainal ◽  
Jean Marc Saiter ◽  
Suhaila Idayu Abdul Halim ◽  
Romain Lucas ◽  
Chin Han Chan

AbstractWe present an overview for the basic fundamental of thermal analysis, which is applicable for educational purposes, especially for lecturers at the universities, who may refer to the articles as the references to “teach” or to “lecture” to final year project students or young researchers who are working on their postgraduate projects. Description of basic instrumentation [i.e. differential scanning calorimetry (DSC) and thermogravimetry (TGA)] covers from what we should know about the instrument, calibration, baseline and samples’ signal. We also provide the step-by-step guides for the estimation of the glass transition temperature after DSC as well as examples and exercises are included, which are applicable for teaching activities. Glass transition temperature is an important property for commercial application of a polymeric material, e.g. packaging, automotive, etc. TGA is also highlighted where the analysis gives important thermal degradation information of a material to avoid sample decomposition during the DSC measurement. The step-by-step guides of the estimation of the activation energy after TGA based on Hoffman’s Arrhenius-like relationship are also provided.


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