scholarly journals Study on Microstructure and Fatigue Properties of FGH96 Nickel-Based Superalloy

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6298
Author(s):  
Yishan Bai ◽  
Shanglei Yang ◽  
Minqi Zhu ◽  
Cong Fan
Keyword(s):  
Synchrotron Radiation ◽  
Cleavage Fracture ◽  
Damage Mechanism ◽  
Propagation Path ◽  
Fatigue Properties ◽  
Second Phase ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Second Phase Particles ◽  
Cleavage Step

In this study, using synchrotron radiation X-ray imaging, the microstructure, tensile properties, and fatigue properties of FGH96 nickel-based superalloy were tested, and the fatigue damage mechanism was analyzed. An analysis of the experimental results shows that the alloy structure is dense without voids or other defects. It was observed that the primary γ′ phase is distributed on the grain boundary in a chain shape, and the secondary γ′ phase is found inside the crystal grains. The X-ray diffraction (XRD) pattern indicates that no other phases were seen except for the γ and γ′ phases. The tensile strength of the alloy is 1570 MPa and the elongation is 12.1%. Using data fitting and calculation, it was found that the fatigue strength of the alloy under the condition of 5 × 106 cycles is 620.33 MPa. A fatigue fracture has the characteristics of secondary crack, cleavage step, fatigue stripe, tire indentation, and dimple. The fracture is a mix of cleavage fracture and ductile fracture. Through a three-dimensional reconstruction of the alloy synchrotron radiation imaging area, it was found that the internal defects are small and mostly distributed at the edge of the sample. The dimple morphology is formed by cavity aggregation and cavity germination resulting from defects in the material itself, fracture of the second-phase particles, and separation of the second-phase particles from the matrix interface. By analyzing the damage mechanism of fatigue fractures, it is concluded that the cleavage step is formed by the intersection of cleavage planes formed by branch cracks, with the main crack of the confluence extending forward to form a cleavage fracture. The crack propagation path was also analyzed, and under the action of cyclic load and tip passivation, the crack shows Z-shaped propagation.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

Nanoscale Three-Dimensional Microstructural Characterization of an Sn-Rich Solder Alloy Using High-Resolution Transmission X-Ray Microscopy (TXM)

2016 ◽  
Vol 22 (4) ◽  
pp. 808-813 ◽  
Author(s):  
Chandrashekara S. Kaira ◽  
Carl R. Mayer ◽  
V. De Andrade ◽  
Francesco De Carlo ◽  
Nikhilesh Chawla
Keyword(s):  
Fresnel Zone ◽  
Three Dimensional ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Full Field ◽  
X Ray ◽  
Second Phase Particles ◽  
Rich Alloy ◽  
Nanoscale Features

AbstractThree-dimensional (3D) nondestructive microstructural characterization was performed using full-field transmission X-ray microscopy on an Sn-rich alloy, at a spatial resolution of 60 nm. This study highlights the use of synchrotron radiation along with Fresnel zone plate optics to perform absorption contrast tomography for analyzing nanoscale features of fine second phase particles distributed in the tin matrix, which are representative of the bulk microstructure. The 3D reconstruction was also used to quantify microstructural details of the analyzed volume.

Observation of second-phase particles in bulk zirconium alloys using synchrotron radiation

2001 ◽  
Vol 294 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Kenneth T. Erwin ◽  
Olivier Delaire ◽  
Arthur T. Motta ◽  
Yong S. Chu ◽  
Derrick C. Mancini ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Zirconium Alloys ◽  
Second Phase ◽  
Second Phase Particles

Synchrotron Radiation Damage Mechanism of X-Ray Mask Membranes Irradiated in Helium Environment

1992 ◽  
Vol 31 (Part 1, No. 12B) ◽  
pp. 4459-4462 ◽  
Author(s):  
Tomiyuki Arakawa ◽  
Hiroshi Okuyama ◽  
Koichi Okada ◽  
Hiroyuki Nagasawa ◽  
Tsutomu Syoki ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Radiation Damage ◽  
Damage Mechanism ◽  
X Ray

scholarly journals A Microstructure Investigation of the Deformation and Recrystallization of Particle-Containing Aluminium-Silicon Alloys

1993 ◽  
Vol 20 (1-4) ◽  
pp. 125-140 ◽  
Author(s):  
F. Habiby ◽  
F. J. Humphreys
Keyword(s):  
Single Crystals ◽  
Recrystallization Texture ◽  
Rolling Texture ◽  
Plasticity Theory ◽  
Second Phase ◽  
Slip Systems ◽  
Deformation Bands ◽  
Silicon Alloys ◽  
X Ray ◽  
Second Phase Particles

Single crystals and polycrystals of aluminium containing non-deformable second-phase particles of silicon, have been deformed, and the resultant structures investigated by microscopy and by X-ray and microtexture techniques. The particle size is found to influence the scale of the deformation bands formed, and there is evidence that particles may affect the nucleation of these bands. The deformed materials were recrystallized, and the effect of particle stimulated nucleation on the weakening of the rolling texture is discussed with reference to a computer simulation. In contrast, the recrystallization texture of particle-containing single crystals deformed on only two slip systems is sharp, and it is shown that the texture components are consistent with plasticity theory.

Study on the Preparation and Micro Structure of the Mg Containing Porous HA with Ultra-Fine Grain

2009 ◽  
Vol 610-613 ◽  
pp. 1132-1136
Author(s):  
Xing Yi Li ◽  
Xiang Cai Meng ◽  
Guo Quan Liu ◽  
Shi Dan Yuan
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Precipitation ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Micro Structure ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron ◽  
Second Phase Particles

The Nano-HA powder were synthesized by chemical precipitation with Ca(H2PO4)2•H2O and Ca (OH)2 and porous HA was prepared by sintering with magnesium as pore-creator. Nano-HA powder and porous HA were characterized by wide angle X-ray diffraction, transmission electron microscopy(TEM), scanning electron microscopy (SEM), SEM in combination with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy. The experimental results show that HA powder synthesized by chemical precipitation is nanometer powder. Magnesium was ideal pore-creator for preparation of porous materials. The grain size of porous HA was sub-micron and MgO which existed in the grain boundary of HA as a second phase particles that played the roles of inhibiting the HA grain growth.

Analytical Microscopic Analysis of Precipitates in Hastelloy Alloy C-276

1981 ◽  
Vol 39 ◽  
pp. 280-281
Author(s):  
M. Raghavan ◽  
B. J. Berkowitz ◽  
J. C. Scanlon
Keyword(s):  
Microscopic Analysis ◽  
Scanning Transmission Electron Microscope ◽  
Second Phase ◽  
Precipitation Reaction ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Scanning Transmission

The present investigation was conducted to characterize the second phase particles in Hastelloy C-276 using an analytical Scanning Transmission Electron Microscope in order to understand their effect on the mechanical and Stress Corrosion properties of the alloy. Investigation in our 1aboratoryO) and previous published reports(2-4) have identified two types of precipitation reactions in this alloy. At temperatures in the range of 300-650°C, the alloy precipitates an ordered phase of the type Ni2(Cr, Mo)(1,2). This precipitation reaction is homogeneous with no preferential precipitation at the grain boundaries or twin boundaries. At temperatures above 650°C, several precipitate phases were observed to nucleate heterogeneously at boundaries and using X-ray diffraction techniques, the precipitates were previously identified as the μ, M6C and P phases(3-4). The present investigation was carried out to determine the composition of these second phase particles and this article describes the characterization of these precipitates using X-ray microanalysis and microdiffraction techniques.

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