scholarly journals Improvements to the two-phase sandwich method for calculating the melting points of pure metals

2019 ◽  
Vol 25 (2) ◽  
pp. 105-116
Author(s):  
Kamil Rybacki ◽  
Szymon Winczewski ◽  
Valeriy Pleechystyy ◽  
Jarosław Rybicki
Keyword(s):  
Melting Points ◽  
Two Phase ◽  
Sandwich Method ◽  
Pure Metals

DSC Investigations of the Phase Transitions of [M(H2O)6](NO3)2 , where M = Mn, Co, Ni, Cu and Zn

1999 ◽  
Vol 54 (10-11) ◽  
pp. 595-598
Author(s):  
E. Mikuli ◽  
A. Migdał-Mikuli ◽  
S. Wróbel ◽  
B. Grad
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Solid Phase ◽  
Melting Process ◽  
Melting Points ◽  
Two Stage ◽  
Two Phase ◽  
Solid Phase Transition ◽  
Cu And Zn

The phase transitions of [M(H2O)6 ](NO3)2 , where M = Mn2+ , Co2+ , Ni2+ , Cu2+ or Zn2+ have been studied at 100 -400 K by DSC. Two phase transitions connected with a two-stage melting process have been found for these five compounds. For the compound with M = Co, besides the two melting points a solid-solid phase transition at 272 K has been found.

Cyanoethylation and (Methoxycarbonyl)ethylation of Icosahedral ortho-Carborane Derivatives at Carbon Vertices via Michael Additions

2001 ◽  
Vol 66 (10) ◽  
pp. 1499-1507 ◽  
Author(s):  
Jaromír Plešek ◽  
Jaroslav Bačkovský ◽  
Jiří Fusek ◽  
Zbyněk Plzák
Keyword(s):  
Mass Spectrometry ◽  
Methyl Acrylate ◽  
Michael Addition ◽  
Nmr Spectra ◽  
Ammonium Hydroxide ◽  
Phase System ◽  
Melting Points ◽  
Two Phase ◽  
Michael Additions

The C-H vertices of ortho-carborane and its derivatives can be smoothly cyanoethylated with acrylonitrile in the presence of benzyl(triethyl)ammonium hydroxide in a two-phase system: dichloromethane/water or 1,2-dimethoxyethane/water. The reaction is highly specific and not transferable to its meta and para isomers. No Michael addition with methyl acrylate takes place under these conditions. However, with NaH as catalyst (methoxycarbonyl)ethylation can be accomplished with ortho-carborane; meta and para isomers react neither with acrylonitrile, nor with methyl acrylate even under such forcing conditions. The syntheses, properties and constitutions of 1-(2-cyanoethyl)-ortho-carborane, 1-(2-cyanoethyl)-2-phenyl-ortho-carborane, 1,2-bis(2-cyanoethyl)-ortho-carborane, 1-[2-(methoxycarbonyl)ethyl]-ortho-carborane and 1,2-bis[2-(methoxycarbonyl)ethyl]-ortho-carborane, along with their respective acids, are described. Melting points, TLC, "heated-inlet" mass spectrometry, and the 1H and 11B NMR spectra of all compounds, are presented. The scope of cyanoethylations and (methoxycarbonyl)ethylations of other deltahedral carbaboranes and heteroboranes is considered.

The formation of two-phase layered scales on pure metals

1974 ◽  
Vol 8 (5) ◽  
pp. 265-281 ◽  
Author(s):  
Gregory J. Yurek ◽  
John P. Hirth ◽  
Robert A. Rapp
Keyword(s):  
Two Phase ◽  
Pure Metals

Effect of Shock Loading on the Microstructure of Uniloy 326

1974 ◽  
Vol 32 ◽  
pp. 504-505
Author(s):  
K. P. Staudhammer ◽  
L. E. Murr
Keyword(s):  
Grain Size ◽  
Shock Loading ◽  
Current Investigation ◽  
Two Phase ◽  
05 C ◽  
Shock Deformation ◽  
Heat Treated

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Shock consolidation of Ni-Ti alloy powder

1986 ◽  
Vol 44 ◽  
pp. 430-431
Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens
Keyword(s):  
Alloy Powder ◽  
Amorphous Material ◽  
Ti Alloy ◽  
Two Phase ◽  
Near Surface ◽  
Optical Micrograph ◽  
Shock Compaction ◽  
Powder Particles ◽  
Ti Powder ◽  
Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

A Comparison of Tem and Apfim to the Interpretation of Modulated Microstructures

1985 ◽  
Vol 43 ◽  
pp. 70-71
Author(s):  
M.G. Burke ◽  
M.K. Miller
Keyword(s):  
Low Temperature ◽  
Microstructural Characterization ◽  
Superlattice Reflection ◽  
High Volume ◽  
Atom Probe ◽  
Dark Field ◽  
Miscibility Gap ◽  
Second Phase ◽  
Two Phase ◽  
Probe Field

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.

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