Study on Glass Forming Ability for the Nd60-xCo15+xAl25 Alloys

2012 ◽  
Vol 583 ◽  
pp. 82-85
Author(s):  
Yong Jun Tang ◽  
Hui Xu ◽  
Xiao Hua Tan ◽  
Hua Man ◽  
Qin Bai

Bulk Nd60-xCo15+xAl25 (where x =0, 2, 5, 8, 11) sheet alloys were prepared by argon arc melting and suction casting a copper mold. Glassing forming ability (GFA) of these alloys was investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Due to the dissimilarity reflected from DSC curves the thermodynamic calculation was applied. The values of Gibbs free energy (∆Gl-x (Tg)) for the amorphous alloys were gave out and some GFA criterions were adopted to make a comparison among the samples.

2005 ◽  
Vol 475-479 ◽  
pp. 3393-3396
Author(s):  
Hui Xu ◽  
Xiao Hua Tan ◽  
Nannan Qi ◽  
Qing Wang ◽  
Yuanda Dong

The glass-forming ability, thermal stability and magnetic properties of the Nd60-xDyxFe30Al10 (x=0, 2, 5) bulk amorphous alloys were investigated by x-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The results show that the glass forming ability of the Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys decrease with increasing Dy content. The as-cast Nd60-xDyxFe30Al10 (x=0, 2, 5) alloys show hard magnetic behavior at room temperature. With increasing Dy content, the intrinsic coercivity of the alloys increase significantly while the saturation magnetization and remanence of the alloys decrease monotonously. With increasing annealed temperature, the intrinsic coercivity of the Nd55Fe30Al10Dy5 alloy decreased significantly, while the saturation magnetization and remanence decrease monotonously. The Nd55Fe30Al10Dy5 alloy shows soft magnetic behavior after annealed at 773K for 30 min.


2011 ◽  
Vol 239-242 ◽  
pp. 1391-1395
Author(s):  
Hui Qin Chen ◽  
Bing Wu ◽  
Zhi Qi Cai ◽  
Pi Hui Pi ◽  
Xiu Fang Wen ◽  
...  

In this manuscript two different fluorinated acrylate copolymers films, one was non-crosslinking Stearyl acrylate/2-(perfluorooctyl) ethyl methacrylate (SA/FOEMA) and another was cross-linked SA/2-hydroxyethyl methacrylate(HEMA)/FOEMA/hexamethylene diisocyanate trimers (N3300), were prepared and their crystallinities were investigated by means of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It can be shown from the XRD results that the value of crystallinities of SA/FOEMA and SA/HEMA/FOEMA/N3300 copolymer were 80.95% and 84.02%, respectively. Based on DSC curves and theoretical thermodynamic analysis , it is indicated that crosslinking can improve crystallinity of copolymer composed of SA and FOEMA.


2002 ◽  
Vol 754 ◽  
Author(s):  
U. Wolff ◽  
B. Yang ◽  
N. Pryds ◽  
J.A. Wert

ABSTRACTThe effect of different Si contents on the glass forming ability (GFA) and the amorphous-to-crystalline transformation has been investigated for the Mg-Cu-Y-Si system. Four Mg60Cu30-yY10Siy (y = 1–5 at.%) alloys were prepared using a relatively simple technique of rapid cooling of the melt in a copper mould. Crystallization was induced by heat treatment of the alloys and the samples were then characterized concerning their microstructure and thermal stability by X-ray diffraction (XRD), optical (OM) and scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) at a constant heating rate. Partial substitution of Cu by Si leads to a transition of the as-cast structure at a constant cooling rate from amorphous to crystalline with increasing Si content. Furthermore, the glass transition temperature (Tg) of the Mg-Cu-Y-Si alloy is lower compared to the Mg-Cu-Y system. The mechanical properties of the bulk Mg-Cu-Y-Si alloys have been investigated and found to vary with the Si content.


2015 ◽  
Vol 60 (1) ◽  
pp. 7-10 ◽  
Author(s):  
K. Błoch ◽  
M. Nabiałek ◽  
M. Dośpiał ◽  
S. Garus

Abstract The aim of this paper is to present the results of crystallization studies for the bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025 Ti0.02W0.02B0.20)98Y2, Fe61Co10TixY6B20, Fe61Co10Ti2Y7B20 alloys. The crystallization of the alloys was studied by differential scanning calorimetry (DSC). The amorphicity of the investigated alloys in the as-quenched state was testified using Mossbauer spectroscopy, X-ray diffractometry and transmission electron microscopy. Moreover, X-ray diffractometry was applied to structure investigations of partially crystallized samples. The crystallization process in the investigated alloys occurs in one or two stages. Two peaks in the DSC curves can be overlapped or well separated indicating the complex crystallization processes. From X-ray diffraction we have stated that in both types of devitrification the crystalline phase can be ascribed to the α-FeCo. In the first stage the crystalline grains seem to grow from the nuclei frozen in the samples during the rapid quenching, whereas in the second one both the growth of the existed grains and creation of new ones during annealing may occur.


2012 ◽  
Vol 271-272 ◽  
pp. 36-41
Author(s):  
Wei Yuan Yu ◽  
Wen Jiang Lu ◽  
Nai Rui Li

Al85Ni10Zr3Y2 and Al80Ni10Zr8-xCuxY2(x=1,2,3,5) alloy ribbons had been prepared by single roller melt-spinning process under vacuum conditions. The ribbons were investigated by X–ray diffraction and differential scanning calorimetry (DSC). The results revealed the strong effect of content of Cu、Zr elements on the glass forming ability and the thermal stability of the alloys. The formation of amorphous alloys are sensitive to contens of these two elements. The completely amorphous alloy or the primary amorphous phase alloy can be obtained when the content of Cu or Zr reach an optimization, otherwise only gaining crystal phase. Al80Ni10Zr7Cu1Y2 and Al80Ni10Zr3Cu5Y2 alloys possess the excellent glass forming ability, which can form the completely amorphous alloy or the composite material of the partial crystal in remaining amorphous.


2008 ◽  
Vol 01 (02) ◽  
pp. 145-149 ◽  
Author(s):  
JUNG MIN NAM ◽  
YONG HEE LEE ◽  
TAE HYUN NAM ◽  
YEON WOOK KIM ◽  
JUNG MOO LEE

Amorphous Ti 50 Ni (50-x) Cu x (at.%) (x = 15, 20 and 25) alloy ribbons were prepared by melt spinning, and then their crystallization behavior was investigated by optical microscopy, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry. Wavenumber (Qp) decreased from 29.40 nm-1 to 29.29 nm-1 and ΔT(T g - T x ) increased from 31 K to 36 K with increasing Cu content from 15 at.% to 25 at.%, suggesting that glass forming ability of Ti – Ni – Cu alloy ribbons increased with increasing Cu content. Activation energy for crystallization decreased from 211.5 kJ/mol to 136.4 kJ/mol with increasing Cu content from 15 at.% to 25 at.%, suggesting that a stability of Ti – Ni – Cu amorphous decreased with increasing Cu content.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


2012 ◽  
Vol 8 ◽  
pp. 371-378 ◽  
Author(s):  
Katharina C Kress ◽  
Martin Kaller ◽  
Kirill V Axenov ◽  
Stefan Tussetschläger ◽  
Sabine Laschat

4-Cyano-1,1'-biphenyl derivatives bearing ω-hydroxyalkyl substituents were reacted with methyl 3-chloro-3-oxopropionate or cyanoacetic acid, giving liquid-crystalline linear malonates and cyanoacetates. These compounds formed monotropic nematic phases at 62 °C down to ambient temperature upon cooling from the isotropic liquid. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction (WAXS).


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