Determination of the sign of the γ/γ′-misfit in nickel-base superalloys by use of spectral impure Cu(Cr) radiation

1997 ◽  
Vol 36 (11) ◽  
pp. 1279-1282 ◽  
Author(s):  
U. Brückner ◽  
A. Epishin ◽  
G. Nolze
Keyword(s):  
Nickel Base Superalloys ◽  
Nickel Base

Determination of the Coherency Strain of γ and γ′ Phases in Nickel-Base Superalloys at High Temperatures

1992 ◽  
Vol 36 ◽  
pp. 515-526
Author(s):  
Katsumi Ohno ◽  
Tadaharu Yokokawa ◽  
Toshihiro Yamagata ◽  
Hiroshi Harada ◽  
Michio Yamazaki ◽  
...  
Keyword(s):  
Lattice Misfit ◽  
Profile Fitting ◽  
Overlapping Peaks ◽  
Nickel Base Superalloys ◽  
Nickel Base ◽  
L12 Structure ◽  
Fcc Structure ◽  
Type Nickel ◽  
Voigt Function

AbstractA method for using syncrotoron-radiation parallel-beam X-ray diffractometry for precise lattice parameters and strains of γ-γ′ type Nickel base superalloys at elevated temperature is described. The superalloys have γ′ precipitates which are an ordered L12 structure based on Ni3Al, in y-matrices having a disordered FCC structure. Lattice misfit between γ and γ′ phases was very small and peaks reflected from γ and γ′ phases made unresolved clusters of peaks.Profile fitting with a pseudo-Voigt function is used to resolve overlapping peaks. Instrumental broadening of the peak profile was removed using a deconvolution method. The standard errors of the calculated peak angle were less than 0.002°. The elastic strain of the γ′ precipitates in the alloys were smaller than those of γ-matrices.

Determination of the Coherency Strain of γ and γ’ Phases in Nickel-Base Superalloys at High Temperatures

1993 ◽  
pp. 515-526
Author(s):  
Katsumi Ohno ◽  
Tadaharu Yokokawa ◽  
Toshihiro Yamagata ◽  
Hiroshi Harada ◽  
Michio Yamazaki ◽  
...  
Keyword(s):  
High Temperatures ◽  
Coherency Strain ◽  
Nickel Base Superalloys ◽  
Nickel Base

Determination of Bismuth in Nickel-Base Superalloys by Atomic Absorption Spectrophotometry

1974 ◽  
Vol 28 (2) ◽  
pp. 192-193 ◽  
Author(s):  
Jaxon A. White ◽  
William L. Harper ◽  
A. Paul Friedman ◽  
Victor E. Banas
Keyword(s):  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Nickel Base Superalloys ◽  
Nickel Base

Analysis of Residual Stress States in Coarse Grained and Single Crystal Nickel-Base Superalloys

1995 ◽  
Vol 39 ◽  
pp. 211-223
Author(s):  
W. Reimers
Keyword(s):  
Single Crystal ◽  
Strain Tensor ◽  
Coarse Grained ◽  
Evaluation Technique ◽  
Crystalline Materials ◽  
Nickel Base Superalloys ◽  
Stress States ◽  
Nickel Base ◽  
Individual Crystallite

The single crystal measuring and evaluation technique allows the analysis of stress states in large grained and single crystalline materials. The technique is based on the analysis of the orientation of crystallites under study. Using a fouf-circle-diffractometer, the knowledge of the orientation matrix allows the calculation of the diffractometer setting for every given reflection (hkl). After experimental determination of the precise diffraction angles 20 for at least six reflections of an individual crystallite, its strain tensor components can be obtained by applying least-squares methods. The stress tensor referred to the crystal axes system is calculated using the single crystal elastic constants.The practical use of this measuring and evaluation technique is demonstrated on coarse grained and single crystal nickel-base superalloys and monocrystalline materials.

Determination of Lattice Parameter and Strain of ϒ' Phases in Nickel-Base Superalloys by Synchrotron Radiation Parallel Beam Diffractometry

1990 ◽  
Vol 34 ◽  
pp. 493-499
Author(s):  
Katsumi Ohno ◽  
Kazumasa Ohsumi ◽  
Hiroshi Harada ◽  
Toshihiro Yamagata ◽  
Michio Tamazaki
Keyword(s):  
Synchrotron Radiation ◽  
Preparation Method ◽  
Turbine Blades ◽  
Lattice Misfit ◽  
Lattice Parameter ◽  
Parallel Beam ◽  
Nickel Base Superalloys ◽  
Nickel Base ◽  
Fcc Structure

AbstractThe lattice parameters and strain of ϒ'-phase particles in Nickel-base superalloys, which are duplex type alloys designed for turbine blades and widely called “Ni-base single crystal superalloys”; they are accurately determined by Synchrotron Radiation parallel-beam diffractometry. The superalloys have ϒ' precipitates, an ordered FCC structure based on Ni3Al, in a γ-matrix having disordered FCC structure.In addition, the preparation method of stress-free ϒ'-phase particles, with no composition change in the preparation process, was newly developed to measure the coherency strain of ϒ'-particles due to lattice misfit. The prepared ϒ'-phase particles are similar in composition and form to ϒ'-phase particles in the γ-matrices. The method for determining of the lattice misfit between the γ and γ’ particles was previously reported.

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