Determination of γ′ solution temperature in Re-rich Ni-base superalloy by small-angle neutron scattering

2001 ◽  
Vol 34 (5) ◽  
pp. 541-548 ◽  
Author(s):  
Pavel Strunz ◽  
Debashis Mukherji ◽  
Ralph Gilles ◽  
Albrecht Wiedenmann ◽  
Hartmut Fuess
Keyword(s):  
Neutron Scattering ◽  
Temperature Dependence ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Volume Fraction ◽  
Solidus Temperature ◽  
Solution Temperature ◽  
Incipient Melting ◽  
Relative Volume Fraction

A harmful segregation of heavy elements (e.g.W, Mo, Re) during solidification of Ni-base superalloys can only be eliminated by using a homogenizing heat treatment, which needs to be carried out in the single-phase (γ) field above the γ′ solvus temperature but below the solidus temperature. Small-angle neutron scattering (SANS) was employed forin situobservation of the dissolution of precipitates in an Re-rich superalloy. The temperature dependence of the relative volume fraction and the size distribution of smaller γ′ precipitates, and the specific surface of large inhomogeneities as well as some other parameters were determined from the two-dimensional scattering curves measured for as-cast and heat-treated samples. Overlap of the incipient melting region with the region where a certain amount of precipitates remained undissolved was observed, thus complicating a determination of the temperature at which all γ′ precipitates are already dissolved. Nevertheless, conclusions about the temperature at which the precipitates dissolve and about the temperature at which the incipient melting starts could be formulated. The total scattering probability is suggested as the measure of the overall homogeneity of the distribution of elements in the sample. The temperature dependence of this parameter indicates the optimum solution procedure.

scholarly journals Determination of γ′ solution temperature in Re-rich Ni-base superalloy by small-angle neutron scattering. Erratum

2001 ◽  
Vol 34 (6) ◽  
pp. 787-787
Author(s):  
Pavel Strunz ◽  
Debashis Mukherji ◽  
Ralph Gilles ◽  
Albrecht Wiedenmann ◽  
Hartmut Fuess
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Complete List ◽  
Solution Temperature ◽  
Base Superalloy

In the paper by Strunzet al.[J. Appl. Cryst.(2001),34, 541–548], Joachim Rösler is missing from the list of authors. The complete list of authors should be: P. Strunz, D. Mukherji, R. Gilles, A. Wiedenmann, J. Rösler and H. Fuess.

Changes in the calcium cluster distribution of ultrafiltered and diafiltered fresh skim milk as observed by Small Angle Neutron Scattering

2011 ◽  
Vol 78 (3) ◽  
pp. 349-356 ◽  
Author(s):  
Marcela Alexander ◽  
Mu-Ping Nieh ◽  
Mary Ann Ferrer ◽  
Milena Corredig
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Membrane Filtration ◽  
Volume Fraction ◽  
Milk Powder ◽  
Skim Milk ◽  
Casein Micelle ◽  
Reconstituted Milk

The effect of ultrafiltration and diafiltration on the distribution of the calcium phosphate clusters of the casein micelle was investigated using Small Angle Neutron Scattering (SANS). In the case of ultrafiltration, fresh skim milk was subjected to concentration using membrane filtration up to 5× its original volume, the retentate was rediluted with its corresponding serum and subsequently dialyzed against reconstituted milk powder dispersed in D2O/H2O (UF 5×(D)). In the case of diafiltered samples, the samples were concentrated adding water (diafiltration) at two different levels (DF 2·5× or DF 5×) and then redispersed with D2O/H2O. In the DF 5× case, the serum components were diluted to less than 1% of their original concentration. For analysis, all samples had the same volume fraction of dispersed casein micelles (φ=0·1), which is that of the control, unprocessed skim milk. A peak in the SANS data was observed in fresh skim milk at a scattering vector, qo, of 0·034 Å−1 (directly proportional to the reciprocal characteristic length), in agreement with previous literature results. Neutron data on the ultrafiltered, UF 5×(D) and diafiltered, DF 2·5× and DF 5× milk samples showed a progressive decrease in the intensity of the peak but invariance in qo. These results, combined with the determination of soluble and insoluble calcium in the samples, suggest a progressive and irreversible removal of calcium from within the micelle during membrane filtration of milk. Using SANS it was possible to clearly show changes in the micellar calcium clusters that may not otherwise be fully determined by only measuring the amount of total and insoluble calcium in milk.

Determination of pore accessibility in silica microparticles by small angle neutron scattering

1985 ◽  
Vol 57 (11) ◽  
pp. 2079-2084 ◽  
Author(s):  
Charles J. Glinka ◽  
Lane C. Sander ◽  
Stephen A. Wise ◽  
Michael L. Hunnicutt ◽  
Charles H. Lochmuller
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Silica Microparticles

Characterization of alumina powder using multiple small-angle neutron scattering. I. Theory

1985 ◽  
Vol 18 (6) ◽  
pp. 467-472 ◽  
Author(s):  
N. F. Berk ◽  
K. A. Hardman-Rhyne
Keyword(s):  
Particle Size ◽  
Phase Shift ◽  
Neutron Scattering ◽  
Multiple Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Volume Fraction ◽  
Scattering Data ◽  
Alumina Powder ◽  
Beam Broadening

Microstructural parameters of high-purity alumina powder are determined quantitatively throughout the bulk of the material using small-angle neutron scattering techniques. A unified theoretical and experimental approach for analyzing multiple scattering data is developed to obtain values for particle size, volume fraction and surface area. It is shown how particle size and volume fraction can be measured in a practical way from SANS data totally dominated by incoherent multiple scattering (`beam broadening'). The general phase-shift dependence of single-particle scattering is incorporated into the multiple scattering formalism, and it is also shown that the diffractive limit (small phase shift) applies even for phase shifts as large as unity (particle radii of order 1 μm). The stability of the Porod law against multiple scattering and the phase-shift scale are described, a useful empirical formula for analysis of beam broadening data is exhibited, and the applicability of the formulations to polydispersed systems is discussed.

scholarly journals Determination of Internal Density Profiles of Smart Acrylamide-Based Microgels by Small-Angle Neutron Scattering: A Multishell Reverse Monte Carlo Approach

Langmuir ◽  
2018 ◽  
Vol 34 (50) ◽  
pp. 15403-15415 ◽  
Author(s):  
Marian Cors ◽  
Lars Wiehemeier ◽  
Yvonne Hertle ◽  
Artem Feoktystov ◽  
Fabrice Cousin ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Reverse Monte Carlo ◽  
Density Profiles ◽  
Monte Carlo Approach

scholarly journals Determination of partial specific volume and absolute concentration by densimetry

1984 ◽  
Vol 219 (3) ◽  
pp. 1049-1052 ◽  
Author(s):  
P H Stothart
Keyword(s):  
Absorption Coefficient ◽  
Neutron Scattering ◽  
Prior Knowledge ◽  
Small Angle ◽  
Specific Volume ◽  
Small Angle Neutron Scattering ◽  
Partial Specific Volume ◽  
Absolute Concentration ◽  
Non Destructive

The apparent partial specific volume, phi, of a protein (or other macromolecule) and the absolute concentration, c, can be determined from the densimetry of solutions and diffusates in 1H2O, 2H2O and 1H2O/2H2O mixtures if the ratios of concentrations (relative concentrations) are known. The densimetry method allows a non-destructive check on total macromolecule concentrations without prior knowledge of specific u.v.-absorption coefficient. The method may be especially useful in small-angle neutron-scattering studies.

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