Solidification sequence and as-cast microstructure of a model Pb-Bi-Sn alloy with quasi-peritectic reaction

AbstractNd:11Fe:Ti alloys prepared by arc melting followed by splat quenching and annealing have been investigated by electron microscopy. The as-cast microstructure evidenced an α-Fe(Ti) → NdFe11Ti → Nd2(Fe,Ti)17 solidification sequence compatible with a cascade of peritectic reactions. The Nd2(Fe,Ti)17 phase was not detected in the microstructure of the splat-quenched materials, but after annealing the ternary compound grains consisted of a mixture of ThMn12-type and Th2Zn17-type structures exhibiting a consistent (020)1:12//(003)2:17 and [100]1:12//[110]2:17, orientation relation, with the invariant plane sitting at (022)1:12//(333)2:17. A series of 3D microdiffraction experiments carried out on grains presenting a random distribution of planar defects has been used to map the reciprocal space of the intergrown phases.

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On the through-process texture evolution assessment in grain oriented Fe-3 wt% Si steel produced by a novel directional inoculation technique

Scientific Reports ◽

10.1038/s41598-021-84360-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Snehashish Tripathy ◽

Sandip Ghosh Chowdhury

Keyword(s):

Magnetic Field ◽

Hot Rolling ◽

Texture Evolution ◽

Lattice Parameter ◽

Soft Magnetic ◽

Oriented Growth ◽

Inoculation Technique ◽

Hot Band ◽

Ebsd Technique ◽

Cast Microstructure

AbstractA novel directional inoculation technique has been designed to cast thin slab ingots containing Goss (or near Goss) oriented components in the as cast microstructure under the combined effect of oriented nucleation and oriented growth. The same has been targeted so as to retain Goss orientations and simultaneously develop γ fiber components (ranging from {111}<$$1\overline{1}0$$ 1 1 ¯ 0 > to {111}<112>) during hot rolling. The designed scheme of directional inoculation achieved oriented nucleation by the effect of exogenously added soft magnetic inoculants under magnetic field and oriented growth by the effect of fast cooling rates prevailing in the mould. The choice of 65Fe–35Co (wt%) system as soft magnetic inoculants was made taking into account the similarity in crystal structure and lattice parameter. The chemically synthesized inoculants under the effect of external magnetic field during solidification were able to exhibit directional inoculation. Variation in the cast microstructure and microtexture by varying the extent of inoculant addition was studied by EBSD technique. The ingots cast under different conditions were subjected to a designed hot rolling schedule and the through process microstructural and microtextural evolution was assessed. It was observed that fine equiaxed grains with initial cube orientations in the as cast structure could lead to the most desirable microstructural as well as microtextural gradient in the hot band.

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Effect of Heat Treatment on the As-Cast Microstructure and Hardness of NiSi3B2 Alloy

Metals ◽

10.3390/met11040539 ◽

2021 ◽

Vol 11 (4) ◽

pp. 539

Author(s):

Gonçalo M. Gorito ◽

Aida B. Moreira ◽

Pedro Lacerda ◽

Manuel F. Vieira ◽

Laura M. M. Ribeiro

Keyword(s):

Heat Treatment ◽

Elevated Temperatures ◽

Casting Process ◽

X Ray Diffraction ◽

Heat Treated ◽

Energy Dispersive Microanalysis ◽

Eutectic Constituent ◽

Backscattered Electron ◽

Corrosion And Oxidation ◽

Cast Microstructure

Cast Ni-Si-B alloys have the potential for high-temperature applications because of their high resistance to wear, impact, corrosion, and oxidation at elevated temperatures due to an appropriate balance of hard phases and austenite that ensures a good compromise between toughness and hardness. In this work, NiSi3B2 specimens, fabricated by the lost-wax casting process, were investigated. Given the complex multiphase cast microstructure, a differential scanning calorimeter (DSC-TGA) analysis was employed to characterize the reactions that occur during solidification and the resulting phases were characterized using scanning electron microscopy (SEM), with energy-dispersive microanalysis (EDS) and backscattered electron (BSE) image and X-ray diffraction (XRD). Due to the presence of hard phases, machining of the Ni-Si-B components can pose additional difficulties. Therefore, the conditions of the solution heat treatment, which might lead to the homogenization of the microstructure, consequently improving its machinability, were also investigated. The results of the heat-treated samples indicated that the dissolution of the eutectic constituent is accompanied by a significant decrease in the hardness (approximately 17%). It is important to emphasize that the solution heat treatments carried out reduced the hardness without affecting the percentage of borides, which will allow improving the machinability without adversely affecting the alloy performance in service.

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Parental Melts and Magma Storage of a Large-volume Dacite Eruption at Vetrovoy Isthmus (Iturup Island, Southern Kuril Islands): Insights into the Genesis of Subduction-zone Dacites

Journal of Petrology ◽

10.1093/petrology/egz032 ◽

2019 ◽

Vol 60 (7) ◽

pp. 1349-1370

Author(s):

S Z Smirnov ◽

A V Rybin ◽

N N Kruk ◽

T Yu Timina ◽

E N Sokolova ◽

...

Keyword(s):

Fluid Inclusion ◽

Large Volume ◽

Peritectic Reaction ◽

Fluid Pressure ◽

Kuril Islands ◽

Strong Increase ◽

Magma Storage ◽

Ti Oxides ◽

Partial Melts ◽

Parental Melts

Abstract Detailed mineralogical and melt and fluid inclusion constraints on magma storage, and the evolution of melts, are presented for the large-volume caldera eruption on the Vetrovoy Isthmus on Itutrup Island (Kuril Islands, Russia). The shallow magma reservoir beneath the Vetrovoy Isthmus is composed of a mush of plagio-rhyolitic melt, phenocrysts and the products of peritectic reaction(s). The melt appears to have formed as a result of partial melting of previously erupted rocks, which probably had andesitic to basaltic compositions and were metamorphosed into amphibole-bearing assemblages. The breakdown of amphibole in the partially melted precursor rocks led to the formation of early Mg-rich clino- and orthopyroxene, along with plagioclase and Fe–Ti oxides, and the release of aqueous fluids. Variations in fluid pressure are recorded by a strong increase of An contents in plagioclase. Crystallization took place at around 850°C with pressure ranging from 0·9 to 3 kbar. This study demonstrates that dacitic magmas erupted during the course of a 20 kyr voluminous eruption were the result of mixing between plagio-rhyolitic partial melts and the breakdown reaction minerals (i.e. pyroxenes, plagioclase and Fe–Ti oxides). Plagioclase and quartz were the last minerals to crystallize from these melts prior to eruption.

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Cast microstructure and tribological properties of particulate TiC-reinforced Ni-base or stainless steel matrix composites

Materials Science and Engineering A ◽

10.1016/0921-5093(94)90903-2 ◽

1994 ◽

Vol 183 (1-2) ◽

pp. 195-204 ◽

Cited By ~ 26

Author(s):

S. Skolianos ◽

T.Z. Kattamis ◽

M. Chen ◽

B.V. Chambers

Keyword(s):

Stainless Steel ◽

Tribological Properties ◽

Steel Matrix ◽

Matrix Composites ◽

Cast Microstructure

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Comparison of As-Cast Microstructures and Mechanical Properties for Mg-Ce-Mn-Sc and Mg-Ce-Mn-Zn Magnesium Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.746 ◽

2009 ◽

Vol 610-613 ◽

pp. 746-749 ◽

Cited By ~ 3

Author(s):

Jia Shen ◽

Ming Bo Yang ◽

Fu Sheng Pan ◽

Ren Ju Cheng

Keyword(s):

Mechanical Properties ◽

Magnesium Alloys ◽

Creep Properties ◽

Microstructures And Mechanical Properties ◽

The Difference ◽

Cast Microstructure

The as-cast microstructures and mechanical properties of Mg-3Ce-1.2Mn-0.9Sc and Mg-3Ce-1.2Mn-1Zn magnesium alloys were investigated and compared. The results indicate that the as-cast microstructure of Mg-3Ce-1.2Mn-0.9Sc alloy was mainly composed of -Mg, Mg12Ce and Mn2Sc phases, and that the as-cast microstructure of Mg-3Ce-1.2Mn-1Zn alloy was mainly composed of -Mg, Mg12Ce and MgZn phases. In addition, the as-cast tensile and creep properties of Mg-3Ce-1.2Mn-0.9Sc alloy were higher than that of the Mg-3Ce-1.2Mn-1Zn alloy. The difference of the two alloys in as-cast tensile and creep properties may be related to the initial microstructures of the two alloys.

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