In situ SANS investigation of the kinetics of rafting of γ′ precipitates in a fourth-generation single-crystal nickel-based superalloy

2008 ◽  
Vol 59 (11) ◽  
pp. 1167-1170 ◽  
Author(s):  
N. Ratel ◽  
B. Demé ◽  
P. Bastie ◽  
P. Caron
Keyword(s):  
Single Crystal ◽  
Fourth Generation ◽  
Nickel Based Superalloy ◽  
Kinetics Of

Microsegregation Induced Inhomogeneity of Coarsening of γ’ Precipitates in a Nickel-Based Single Crystal Superalloy

2010 ◽  
Vol 297-301 ◽  
pp. 826-831 ◽  
Author(s):  
Marek Gebura ◽  
Juraj Lapin
Keyword(s):  
Single Crystal ◽  
Interdendritic Region ◽  
Ageing Time ◽  
Effective Diffusion ◽  
Chemical Heterogeneity ◽  
Significant Statistical Difference ◽  
Nickel Based Superalloy ◽  
Time Exponent ◽  
Coarsening Kinetics ◽  
Kinetics Of

Microsegregation induced inhomogeneity of the coarsening of cuboidal γ’(Ni3(Al,Ti)) precipitates was studied in a single crystal nickel-based superalloy CMSX-4 at temperatures ranging from 850 to 1000 °C and for an ageing time up to 5000 h. Experimental results showed a significant statistical difference in the size of the γ’ precipitates between the dendrites and interdendritic region. The achieved results are analyzed and discussed from the point of chemical heterogeneity, activation energy for coarsening, time exponent, effective diffusion coefficient and γ/γ’ interfacial energy which control coarsening kinetics of the cuboidal γ’ precipitates within the dendrites and interdendritic region.

Etching Kinetics of (100) Single Crystal Diamond Surfaces in a Hydrogen Microwave Plasma, Studied with In Situ Low-Coherence Interferometry

2017 ◽  
Vol 214 (11) ◽  
pp. 1700177 ◽  
Author(s):  
Vladimir Yurov ◽  
Egor Bushuev ◽  
Andrey Bolshakov ◽  
Evgeny Ashkinazi ◽  
Irina Antonova ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Diamond Surfaces ◽  
Low Coherence ◽  
Low Coherence Interferometry ◽  
Single Crystal Diamond ◽  
Kinetics Of

The Kinetics of Oxidation of Ru-Bearing Nickel-Based Superalloys

2008 ◽  
Vol 595-598 ◽  
pp. 59-67 ◽  
Author(s):  
I.M. Edmonds ◽  
Hugh E. Evans ◽  
C.N. Jones ◽  
Robert W. Broomfield
Keyword(s):  
Rate Constants ◽  
Initial Period ◽  
Anomalous Behaviour ◽  
Fourth Generation ◽  
Third Generation ◽  
Alumina Layer ◽  
Kinetics Of Oxidation ◽  
Transient Oxidation ◽  
Kinetics Of

Oxidation tests have been undertaken in air on two experimental fourth-generation Nibased superalloys containing, respectively, 3 and 5 wt.% Ru. A Ru-free, third generation alloy (CMSX-10K) was also included in the test programme which used temperatures covering the range 750-1100°C. Where possible, comparisons were also made with literature data on the secondgeneration CMSX-4 alloy and with IN738. After an initial period of transient oxidation, the subsequent parabolic rate constants for the 3%-Ru alloy were similar to those for CMSX-4 at all temperatures above 750°C. At 1000 and 1100°C these were consistent with the formation and growth of an α-alumina layer. At 950°C and lower, protective oxidation was obtained through the formation of an Al-rich spinel rather than alumina but, again, no deleterious influence of Ru additions could be found, at least in the temperature range of 800-950°C. Anomalous behaviour was found, however, at 750°C in that the Ru-bearing alloys oxidised non-protectively through the formation of sub-surface pits in which the γ΄ phase within the alloy was oxidised in situ.

scholarly journals KINETICS OF LOW PRESSURE AMMONIA OXIDATION OVER RH(111)

2018 ◽  
Vol 48 (1) ◽  
pp. 27-30
Author(s):  
U. N. FAGIOLI ◽  
B. V. BOEHN ◽  
M. RAFTI ◽  
R. IMBIHL
Keyword(s):  
Single Crystal ◽  
Mass Spectroscopy ◽  
Pressure Range ◽  
Ammonia Oxidation ◽  
Low Pressure ◽  
Quadrupole Mass ◽  
Catalytic Surface ◽  
Sticking Coefficients ◽  
Kinetics Of

The kinetics of the NH3 + O2 reaction over a Rh(111) single crystal catalytic surface was explored in the 10-6 mbar pressure range at temperatures between 300-900 K. Selectivity towards N2 and NO products, and reactive sticking coefficients were monitored in situ using differentially pumped quadrupole mass spectroscopy (QMS).

scholarly journals In-situ X-ray diffraction snapshotting: Determination of the kinetics of a photodimerization within a single crystal

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Fei-Long Hu ◽  
Shu-Long Wang ◽  
Jian-Ping Lang ◽  
Brendan F. Abrahams
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Kinetics Of

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

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