Structure of Ni-B-Melts by Means of X-Ray Diffraction

1983 ◽  
Vol 38 (10) ◽  
pp. 1098-1102
Author(s):  
E. Nassif ◽  
P. Lamparter ◽  
B. Sedelmeyer ◽  
S. Steeb
Keyword(s):  
Metallic Glass ◽  
Structure Factor ◽  
Amorphous State ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Melt Spin ◽  
Total Structure Factor ◽  
Total Structure

Abstract The structural results for molten Ni81B19 are compared with the structure of a metallic glass which can be obtained at the same composition by rapid quenching the melt within a melt spin equipment. Structural relationship exists between the molten and the amorphous state. This feature follows especially from a marked asymmetry of the second maximum of the structure factor obtained from the melts, to which corresponds the splitting up of the second maximum in the total structure factor of the amorphous specimen. With the Ni53B47- and the Ni43B57 -melts which don't belong to the concentration range of glass-forming Ni-B-melts no peculiarities in the range of the second maximum of the structure factor were observed.

Structure of Mn-Si-Melts by Means of X-Ray Diffraction

1983 ◽  
Vol 38 (10) ◽  
pp. 1093-1097 ◽  
Author(s):  
E. Nassif ◽  
P. Lamparter ◽  
B. Sedelmeyer ◽  
S. Steeb
Keyword(s):  
Structure Factor ◽  
Melt Spinning ◽  
Pair Correlation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Numbers ◽  
Glass Forming ◽  
Structure Factors ◽  
Total Structure Factor ◽  
Total Structure

Abstract The binary molten alloys Mn74Si26 and Mn33.5Si66.5 have been investigated by means of X-ray diffraction. The total structure factors as well as the total pair correlation functions were evaluated. The interatomic distances and total coordination numbers are given. The structural results for Mn74Si26 were compared to those for amorphous Mn74Si23P3 and for a tetrahedral packing model. A pronounced shoulder on the second maximum of the structure factor, which normally is characteristic for the curves obtained with amorphous substances was observed for the Mn74Si26 melt. With the Mn33.5Si66.5 melt, however, this feature cold not be observed. Since with this concentration no glass forming by melt spinning is possible, a correlation between the shape of the second maximum of a total structure factor and the glass forming ability of the corresponding melt is suggested.

scholarly journals High-Energy X-ray Diffraction Study of Liquid Structure of Metallic Glass-Forming Zr70Cu30 Alloy

2005 ◽  
Vol 46 (12) ◽  
pp. 2799-2802 ◽  
Author(s):  
Akitoshi Mizuno ◽  
Seiichi Matsumura ◽  
Masahito Watanabe ◽  
Shinji Kohara ◽  
Masaki Takata
Keyword(s):  
Metallic Glass ◽  
Diffraction Study ◽  
Liquid Structure ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming

In situ high-energy x-ray diffraction observation of structural evolution in a Ti-based bulk metallic glass upon heating

2010 ◽  
Vol 25 (12) ◽  
pp. 2271-2277 ◽  
Author(s):  
N. Zheng ◽  
G. Wang ◽  
L.C. Zhang ◽  
M. Calin ◽  
M. Stoica ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Free Volume ◽  
Structural Relaxation ◽  
Structural Evolution ◽  
High Energy ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
X Ray

The structural evolution of the Ti40Zr10Cu34Pd14Sn2 bulk metallic glass (BMG) upon was investigated by means of in situ high-energy x-ray diffraction. The position, width, and intensity of the first peak in diffraction patterns are fitted through Voigt function below 800 K. All the peak position, width, and intensity values show a nearly linear increase with the increasing temperature to the onset temperature of structural relaxation, Tr = 510 K. However, these values start to deviate from the linear behavior between Tr and Tg (the glass transition temperature). The changes in free volume and the coefficient of volume thermal expansion prove that the aforementioned phenomenon is closely related to the structural relaxation releasing excess free volume arrested during rapid quenching of the BMG. Above 800 K, three crystallization events are detected and the first exothermic event is due to the formation of metastable nanocrystals.

Influence of Rapid Quenching on Magnetocaloric Effect of Y2(Fe,Mn)17 Intermetallic Compounds

2015 ◽  
Vol 233-234 ◽  
pp. 196-199 ◽  
Author(s):  
Alexey I. Zvonov ◽  
N.Yu. Pankratov ◽  
Dmitriy Karpenkov ◽  
Alexey Karpenkov ◽  
S.A. Nikitin
Keyword(s):  
Crystal Structure ◽  
Magnetocaloric Effect ◽  
Low Cost ◽  
Rapid Quenching ◽  
Glass Forming Ability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Polycrystalline Alloys ◽  
Direct Measurements

The melt-spun Y2(Fe,Mn)17ribbons were synthesized by rapid quenching from the melt. The phase composition, crystal structure and magnetocaloric effect (MCE) in low-cost iron-based pseudo-binary Y2(Fe,Mn)17ribbons were investigated respectively by using x-ray diffraction and direct measurements of MCE. It was found that crystal structure of the as-spun ribbons retains hexagonal Th2Ni17-type because of the weak glass-forming ability. The Y2Fe14Mn3and Y2Fe13Mn4nanostructured ribbons demonstrate higher MCE compare to polycrystalline alloys.

Phase Equilibria in the Zr-Cu-Al System: Implications for Bulk Metallic Glass Formation

1998 ◽  
Vol 554 ◽  
Author(s):  
S. A. Syed ◽  
D. Swenson
Keyword(s):  
Ternary Phase ◽  
Amorphous State ◽  
Bulk Amorphous Alloy ◽  
Alloy Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Equilibrium Relationships ◽  
Equilibrium Phases ◽  
Preliminary Phase

AbstractPreliminary phase equilibrium relationships have been established in the Zr-Cu-Al system at 800 °C, using a combination of X-ray diffraction and electron probe microanalysis. These results are similar to previous investigations that have been reported in the literature. Several ternary phases are found to exist in this system, many of which lie within the gross compositional vicinity of interest to bulk amorphous alloy formation. The equilibrium phases present in the alloy Zr65Cu27.5A17.5, which exhibits a particularly high Tx-Tg in the amorphous state, are Zr2Cu and minor amounts of two additional phases: Zr3Al and what may be a ternary phase with a composition near Zr6CuAl3. When the 800 °C phase diagram isotherm is correlated with the known glass forming composition range of the Zr-Cu-Al system, it is found that the best glass forming behavior is confined to those regions of the diagram in which all equilibria include Zr-Cu constituent binary phases and Al-poor ternary phases. This may suggest that difficulties in the nucleation of these binary phases plays a role in the glass forming ability of Zr-Cu-Al and related higher order alloys.

X-ray Diffraction Study of Molten Te and Tl-Te Alloys

1975 ◽  
Vol 30 (12) ◽  
pp. 1655-1660 ◽  
Author(s):  
Y. Waseda ◽  
S. Tamaki
Keyword(s):  
Structure Factor ◽  
Molten Metals ◽  
X Ray Diffraction ◽  
Partial Structure ◽  
X Ray ◽  
Partial Structures ◽  
Structure Factors ◽  
Diffraction Patterns ◽  
Total Structure ◽  
Constituent Elements

Abstract X-ray diffraction patterns have been obtained from molten Te at 470, 520 and 570 °C. The heights of the peak maxima in the structure factor were much the same in contrast with those of typical molten metals such as sodium.Molten Tl-Te alloys have been studied by X-ray diffraction for the alloy compositions 25, 33.3, 50, 60 and 75 at% Te at 500 °C and at about 20 °C above the liquidus. The total structure factors for the 25 and 33.3 at% Te alloys were almost the same as that of pure Tl. This implies that the atomic arrangement of these molten alloys is very close to that of pure Tl. Although a drastic change is not found in the general form of the structure factor, the parameter of the range of local atomic order abruptly increases on passing from Tl2Te to more Te-rich alloys. The three partial structures were also evaluated from the observed X-ray intensities assuming that each partial structure is independent of the relative abundance of the constituent elements in the alloys.

X-Ray Diffraction Study on the Structure of Molten MgxZn(100 -x)-Alloys

1987 ◽  
Vol 42 (5) ◽  
pp. 507-510 ◽  
Author(s):  
E. Bühler ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Amorphous Alloy ◽  
Short Range ◽  
Short Range Order ◽  
Pair Correlation ◽  
Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nearest Neighbours ◽  
Total Structure Factor ◽  
Total Structure

By means of X-ray diffraction in transmission the molten MgxZn(1oo-x)-alloys (x = 0, 8, 15, 30, 40, 50, 60, 70, 73, 80, 90, 100) were investigated and the total structure factor S (Q) , the total pair correlation function, the number of nearest neighbours as well as the atomic distances were evaluated. For 30 ≦ x ≦ 80 a premaximum in S (Q) was observed which is caused by chemical short range order. The comparison of the premaximum of the Mg70Zn30-melt with that of the corresponding amorphous alloy shows that within the melt the chemical short range order amounts to about 40% of that of the amorphous alloy.

Processing and Properties of Amorphous Magnesium-Based Eco-Materials

2011 ◽  
Vol 695 ◽  
pp. 186-189 ◽  
Author(s):  
X. L. Fu ◽  
Ming Jen Tan ◽  
Anders W.E. Jarfors ◽  
Manoj Gupta
Keyword(s):  
Magnesium Alloys ◽  
Amorphous State ◽  
Tensile Tests ◽  
Transportation Industry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming ◽  
Total Failure ◽  
High Temperature Tensile ◽  
Room Temperature Strength

Magnesium alloys are the lightest known structural material and have been very attractive for usage in marine and transportation industry (for its weight savings and payload increase), and also for its portability in hand-held devices. It is recyclable and one of the most abundant metal. Lately, it has gained attention for its biocompatibility, and also its biodegradable properties depending on the alloying elements. They can be used as a biomaterial in various applications from heart stents to implant screws and fixtures. In this work, amorphous magnesium alloys have been processed, based on its glass forming ability, by various techniques in order to obtain its amorphous state, and the microstructure are characterized by thermal analysis, X-ray diffraction and electron microscopy. Their mechanical properties are also presented. High temperature tensile tests show similar strength to room temperature strength, while the total failure strain is significantly increased from around 0.5% to 10%.

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