Microstructures and Precipitation in a Rapidly Solidified Copper-Beryllium Alloy

1985 ◽  
Vol 43 ◽  
pp. 58-59
Author(s):  
A. Guha
Keyword(s):  
Melt Spinning ◽  
Salt Bath ◽  
Nominal Composition ◽  
Thin Foils ◽  
Transmission Electron ◽  
Processed Material ◽  
Strip Cast ◽  
Rapidly Solidified ◽  
Melt Spinning Technique ◽  
Copper Beryllium

A study of direct strip cast copper-beryllium alloys is of interest to determine if enhanced properties could be obtained from rapidly solidified material compared to those of conventionally processed material. The present investigation was undertaken to characterize the as-cast microstructure of this material and to study the metastable phases which formed in this alloy as a result of precipitation from the rapidly quenched condition.The melt spinning technique was used to produce ribbons of a copper-beryllium alloy of nominal composition Cu-1.90wt% Be containing 0.25 wt% cobalt. The as-cast ribbon was approximately 0.1 mm thick and 12 mm wide. The Metglas Products Division of Allied Corporation provided the material. As-cast specimens were salt bath aged at 370 C for 5 min or 3 hours. Thin foils for transmission electron microscopy (TEM) were prepared from the melt spun ribbons by electrolytically thinning in a twin-jet electropolisher using a solution of 30% nitric acid in methanol at -30 C and 25 volts. The specimens were examined in a Siemens 102 transmission electron microscope operating at 125 kV.

Rapidly Solidified Melt-spun Bi-Sn Ribbons: Surface Composition Issues

2016 ◽  
pp. 3287-3297
Author(s):  
Tarek El Ashram ◽  
Ana P. Carapeto ◽  
Ana M. Botelho do Rego
Keyword(s):  
Chemical Composition ◽  
Optical Microscopy ◽  
Melt Spinning ◽  
Surface Composition ◽  
Electrochemical Process ◽  
Melt Spun ◽  
Bismuth Alloy ◽  
The One ◽  
Rapidly Solidified ◽  
Melt Spinning Technique

Tin-bismuth alloy ribbons were produced using melt-spinning technique. The two main surfaces (in contact with the rotating wheel and exposed to the air) were characterized with Optical Microscopy and AFM, revealing that the surface exposed to the air is duller (due to a long-range heterogeneity) than the opposite surface. Also the XPS chemical composition revealed many differences between them both on the corrosion extension and on the total relative amounts of tin and bismuth. For instance, for the specific case of an alloy with a composition Bi-4 wt % Sn, the XPS atomic ratios Sn/Bi are 1.1 and 3.7 for the surface in contact with the rotating wheel and for the one exposed to air, respectively, showing, additionally, that a large segregation of tin at the surface exists (nominal ratio should be 0.073). This segregation was interpreted as the result of the electrochemical process yielding the corrosion products.

The Metastable Micro-Nanocrystals and Formation Mechanism of Rapidly Solidified Al-21Si Multi-Alloys

2014 ◽  
Vol 636 ◽  
pp. 97-100 ◽  
Author(s):  
Ai Qin Wang ◽  
Hui Hui Han ◽  
Jing Pei Xie ◽  
Ji Wen Li
Keyword(s):  
Formation Mechanism ◽  
Melt Spinning ◽  
Primary Silicon ◽  
Nucleation And Growth ◽  
Microstructure Formation ◽  
Microstructure Morphology ◽  
Alloy Microstructure ◽  
Rapidly Solidified ◽  
Melt Spinning Technique ◽  
Scanning Electron

In the present work, rapidly solidified Al-21Si-0.8Mg-1.5Cu-0.5Mn alloys strips was prepared by melt-spinning technique. The microstructure morphology and phase structures of experimental alloy were characterized by means of scanning electron microscopy (SEM), transmission electric microscopy (TEM) and XRD technique. The results show that the grains were refined and the micro-nanocomposite structural were formed under rapid solidification. The nucleation and growth of primary silicon were suppressed and primary silicon could not deposited, meanwhile, α-Al phase was nucleated which prior to eutectic. The microstructure of the Al-21Si alloy was composed of micro-nanostructured α-Al phase and feather-needles-like eutectic α-Al+β-Si phase. The hypereutectic Al-21Si alloy showed the hypoeutectic microstructure. The rapidly solidified Al-21Si alloy microstructure formation mechanism has also been discussed.

scholarly journals MICROSTRUCTURE AND THERMAL STABILITY OF Al-Fe-X ALLOYS

2018 ◽  
Vol 24 (3) ◽  
pp. 223 ◽  
Author(s):  
Andrea Školáková ◽  
Petra Hanusová ◽  
Filip Průša ◽  
Pavel Salvetr ◽  
Pavel Novák ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
Dispersed Particles ◽  
Cast Alloys ◽  
Rapidly Solidified ◽  
Thermal Stability Of ◽  
Melt Spinning Technique ◽  
Extrusion Method

<p>In this work, Al-11Fe, Al-7Fe-4Ni and Al-7Fe-4Cr (in wt. %) alloys were prepared by combination of casting and hot extrusion. Microstructures of as-cast alloys were composed of aluminium matrix with large and coarse intermetallics such as Al<sub>13</sub>Fe<sub>4</sub>, Al<sub>13</sub>Cr<sub>2</sub> and Al<sub>5</sub>Cr. Subsequently, as-cast alloys were rapidly solidified by melt-spinning technique which led to the supersaturation of solid solution alloying elements. These rapidly solidified ribbons were milled and compacted by hot-extrusion method. Hot-extrusion caused that microstructures of all alloys were fine with uniform dispersed particles. Moreover, long-term thermal stability was tested at temperature 300 °C for as-cast and hot-extruded alloys and chromium was found to be the most suitable element for alloying to improve thermal stability.    </p>

Observation of linear defects in Al particles below 7 nm in size

2006 ◽  
Vol 21 (6) ◽  
pp. 1347-1350 ◽  
Author(s):  
Dmitri V. Louzguine-Luzgin ◽  
Akihisa Inoue
Keyword(s):  
Melt Spinning ◽  
Glassy Matrix ◽  
X Ray ◽  
Al Nanoparticles ◽  
Linear Defects ◽  
Transmission Electron ◽  
Ribbon Sample ◽  
Highly Dispersed ◽  
Co Alloys ◽  
Melt Spinning Technique

An as-solidified structure of an Al-based ribbon sample produced by the melt-spinning technique was studied by x-ray diffractometry and transmission electron microscopy. The addition of Pd to Al-Y-Ni-Co alloys caused formation of the highly dispersed primary α-Al nanoparticles about 3–5 nm in size homogeneously embedded in the glassy matrix upon solidification. The first direct observation of microstrain and dislocations quenched in nanoparticles with a size below 7 nm is provided.

scholarly journals Structure of Rapidly Solidified Al-Fe-Cr-Ce Alloy

2011 ◽  
Vol 465 ◽  
pp. 199-202 ◽  
Author(s):  
Alena Michalcová ◽  
Dalibor Vojtěch ◽  
Pavel Novák ◽  
Ivan Procházka ◽  
Jakub Čížek ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Positron Annihilation ◽  
Melt Spinning ◽  
Positron Annihilation Spectroscopy ◽  
Transmission Electron ◽  
Rapidly Solidified ◽  
Thermal Stability Of

An alloy containing Al – 3wt.% Cr – 3wt.% Fe – 0.8wt. % Ce, was prepared by melt spinning. Structure of obtained ribbons was observed by light, scanning and transmission electron microscopy. It was found out that the structure is very fine. Microhardness of cross sectioned ribbons was also measured. Defects in structure were determined by positron annihilation spectroscopy. The thermal stability of the alloy was observed by comparing rapidly solidified ribbons and ribbons annealed at 400°C and at 500°C for 100 h

A Transmission Electron Microscopy study of the B2-DO3 ordering phase transformations in Fe-6.3wt% Si after rapid quenching and annealing

1988 ◽  
Vol 46 ◽  
pp. 772-773
Author(s):  
J. E. Wittig
Keyword(s):  
Phase Transformations ◽  
Melt Spinning ◽  
Magnetic Behavior ◽  
Microscopy Study ◽  
Rapid Quenching ◽  
Electron Microscopy Study ◽  
Silicon Alloys ◽  
Brittle Behavior ◽  
Transmission Electron ◽  
Rapidly Solidified

Iron-silicon alloys are extensively used in transformer cores owing to exceptional soft magnetic behavior that is optimized at about 6.5 wt% Si. Unfortunately this equilibrium microstructure is completely brittle at room temperature. The brittle behavior coincides with the onset of an ordering reaction of the disordered A2 into the B2 and DO3 superlattices at approximately 5 wt% Si. Rapid solidification methods have been shown to improve the ductility of Fe- 6.3 to 6.5 wt% Si. In this investigation, rapidly quenched and annealed samples of Fe-6.3wt% Si were examined in the transmission electron microscope (TEM) to study the ordering phase transformations of this alloy and its effect on the mechanical behavior.Samples of Fe-6.3wt% Si were rapidly solidified by melt spinning into ribbons (t=20-80 microns) as well as by splatting using an opposing piston double anvil method. Rapidly quenched samples were subsequently heat treated in evacuated quartz tubes at 500, 600, and 700 C for 24 h.

Microstructures of Rapidly Solidified Aluminum Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
J.W. Zindel ◽  
J.T. Stanley ◽  
R.D. Field ◽  
H.L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Melt Spinning ◽  
Metastable Phase ◽  
Laser Surface ◽  
Metastable Phase Diagram ◽  
Transmission Electron ◽  
Ternary Additions ◽  
Rapidly Solidified

ABSTRACTAn investigation was performed to study the origin and stability of microstructures in rapidly solidified aluminum alloys. Al-Ni and Al-Fe base alloys were rapidly solidified by means of laser surface melting and melt spinning techniques. Microstructures were studied using optical and transmission electron microscopy. The effect of microstructure on mechanical properties was also studied using microhardness measurements. The origin of the observed microstructural constituents will be explained in terms of features of the metastable phase diagram. The effect of ternary additions on stability will also be considered.

Microstructural analysis for Sn-Bi-Sb-In alloy prepared by rapid solidification

2016 ◽  
Vol 12 (2) ◽  
pp. 4244-4254
Author(s):  
Sara Mosaad Mahlab ◽  
Mustafa Kamal ◽  
Abd El-Raouf Mansour
Keyword(s):  
Electron Microscopy ◽  
Microstructure Evolution ◽  
Melt Spinning ◽  
Vickers Microhardness ◽  
Microstructural Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapidly Solidified ◽  
Melt Spinning Technique ◽  
Scanning Electron

In the present study, Sn70-X at.% -Bi15 at.% -Sb15 at.%- Inx at.%  alloy ( x= 0, 2, 4, 6),  were prepared by melt spinning technique. Optical microscopy, scanning electron microscopy combined with energy dispersive X-ray analysis (SEM-EDX), X-ray diffraction analysis (XRD), and Vickers microhardness (Hv); were used to characterize the phase transformation and the microstructure evolution. The results contribute to the understanding of the microstructure evolution in alloys of the type prepared by melt spinning technique. This work reports on a comparative study of the rapidly solidified, in order to compare the microhardness and microstructural analysis. 

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