Effect of rapid solidification and calcium additions on Sn-38 wt.%Pb-6 wt.%Sb melt-spun alloys

The effect of calcium additions on the structure and physical properties of melt-spun process Sn-38Pb-6Sb alloys have been experimentally investigated at a solidification rate of ~105 K/s. Structure, internal friction, elastic moduli, microhardness and electrical resistivity of the Sn-38%Pb , Sn-38%Pb -6%Sb , Sn-38%Pb -6%Sb-0.5%Ca , Sn-38%Pb -6%Sb -1%Ca , Sn-38%Pb -6%Sb -1.5%Ca , Sn-38%Pb -6%Sb -2%Ca , Sn-38%Pb -6%Sb -2.5%Ca (in wt%) rapidly solidified alloys are investigated. The results showed that the mechanical and electrical properties values are enhanced for ternary Sn-38%Pb -6%Sb alloy. The examined mechanical and electrical conductivity decreased by addition of calcium content in the studied alloys. It also leads to with increasing Ca content the SnSb inter-metallic compound (IMC) precipitates are increased in the Sn matrix. The results were explained in terms of the dislocation theory, effect of quenching rate on the produced density fluctuations in composition and the modes of interaction of crystal lattice defects.

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Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117340 ◽

1985 ◽

Vol 43 ◽

pp. 54-55

Author(s):

L. A. Bendersky ◽

W. J. Boettinger

Keyword(s):

Solid State ◽

Processing Parameters ◽

Heat Extraction ◽

Solid State Reactions ◽

Careful Examination ◽

Ion Milling ◽

Melt Spun ◽

Wheel Side ◽

Rapidly Solidified ◽

Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

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Spherulite Structures in a Melt Spun Fe-Ni Austenitic Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117339 ◽

1985 ◽

Vol 43 ◽

pp. 52-53

Author(s):

G. M. Michal ◽

T. K. Glasgow ◽

T. J. Moore

Keyword(s):

Austenitic Steel ◽

Room Temperature ◽

Elevated Temperatures ◽

Large Range ◽

Amorphous Structure ◽

Nucleation And Growth ◽

Ni Alloys ◽

Melt Spun ◽

Crystal Fibers ◽

Rapidly Solidified

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.

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

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i5.369 ◽

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.

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An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v10i2.1336 ◽

2015 ◽

Vol 10 (2) ◽

pp. 2663-2681

Author(s):

Rizk El- Sayed ◽

Mustafa Kamal ◽

Abu-Bakr El-Bediwi ◽

Qutaiba Rasheed Solaiman

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Melt Spinning ◽

Elastic Moduli ◽

Mechanical Stability ◽

Microstructural Analysis ◽

Alloy System ◽

Antimony Content ◽

The Stability ◽

Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as meltâ€“spun ribbons Â as a function of antimony content .The stabilityÂ of these structures hasÂ beenÂ related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition. Â The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes.Â

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X-ray and Mössbauer study of rapidly solidified Ce20Fe80 ribbons; effect of the quenching rate

Hyperfine Interactions ◽

10.1007/bf02068703 ◽

1994 ◽

Vol 88 (1) ◽

pp. 65-71 ◽

Cited By ~ 6

Author(s):

G. Roulin ◽

J. Teillet ◽

A. Fnidiki ◽

B. Labulle ◽

P. Ochin

Keyword(s):

Mössbauer Study ◽

Quenching Rate ◽

X Ray ◽

Rapidly Solidified

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Microstructures in Rapidly Solidified Ll2-TYPE Ni-Al-Cr Alloys

MRS Proceedings ◽

10.1557/proc-39-125 ◽

1984 ◽

Vol 39 ◽

Author(s):

S. C. Huang ◽

K. M. Chang ◽

E. L. Hall ◽

R. F. Laforce

Keyword(s):

Phase Separation ◽

Cooling Rate ◽

Phase Reaction ◽

Microstructural Study ◽

Melt Spun ◽

Rapidly Solidified

ABSTRACTA microstructural study of the melt spun alloys Ni75 Al25. Ni72.5 Al22.5Cr5. and Ni67.5A120Cr12.5 was carried out. Variations in grain morpfology; phase separation and ordering structure were observed. The results are discussed in terms of alloy stoichiometry, Cr effect on phase reaction, microsegregation of Al and the cooling rate.

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On gamma-irradiation effects on the mechanical properties of rapidly solidified Al-Sn and Al-Sb melt-spun alloys

Radiation Effects and Defects in Solids ◽

10.1080/10420159508225751 ◽

1995 ◽

Vol 133 (1) ◽

pp. 5-13 ◽

Cited By ~ 9

Author(s):

A. M. Shaban ◽

M. Kamal

Keyword(s):

Mechanical Properties ◽

Gamma Irradiation ◽

Irradiation Effects ◽

Melt Spun ◽

Rapidly Solidified

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Microstructure of Nb3 (AlSiB) superconducting tapes with extremely high critical current densities

Journal of Materials Research ◽

10.1557/jmr.1989.0526 ◽

1989 ◽

Vol 4 (3) ◽

pp. 526-529 ◽

Cited By ~ 2

Author(s):

Mireille Treuil Clapp ◽

Zhang Jian ◽

Tariq Manzur

Keyword(s):

Critical Current ◽

Melt Spinning ◽

Quenching Rate ◽

Fine Grained ◽

Annealing Conditions ◽

Second Phases ◽

Current Densities ◽

Rapidly Solidified ◽

Equiaxed Grains ◽

A15 Phase

Alloys of Nb73Al12Si14.5B0.5 were rapidly solidified into amorphous ribbons using the melt spinning technique. These were isothermally annealed at temperatures ranging from 660 to 780 °C. The A15 phase began to crystallize at 700 °C and small amounts of second phases appeared at the higher temperatures. Crystallization was dependent on quenching rate as well as annealing conditions. Below 750 °C nucleation was nonuniform and was enhanced by surfaces and quenched-in nuclei. Above 750 °C nucleation became more uniform and completely crystalline ribbons with equiaxed grains ∼30 nm in diameter were obtained. These ultra fine grained ribbons had extremely high superconducting critical current densities of 8 × 1010 A/m2 and 5 × 1010 A/m2 at magnetic fields of 0.5 and 15 tesla, respectively, at 4.2 K.

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