Oxidation of Intermetallic Precipitates in Zircaloy-4: Impact of Irradiation

2009 ◽  
pp. 687-687-19 ◽  
Author(s):  
D Pe^cheur ◽  
F Lefebvre ◽  
AT Motta ◽  
C Lemaignan ◽  
D Charquet
Keyword(s):  
Intermetallic Precipitates

Microanalytical Identification of a New Zr-Nb-Fe Phase

1990 ◽  
Vol 48 (2) ◽  
pp. 132-133
Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter
Keyword(s):  
Trace Elements ◽  
Cold Rolling ◽  
Proportionality Factor ◽  
Tube Material ◽  
X Ray ◽  
Metal Foils ◽  
Arc Melting ◽  
Intermetallic Particles ◽  
Intermetallic Precipitates ◽  
Cold Worked

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.

The role of intermetallic precipitates in Ti-62222S

1996 ◽  
Vol 213 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
Daniel J. Evans ◽  
Thomas F. Broderick ◽  
John B. Woodhouse ◽  
James R. Hoenigman
Keyword(s):  
Intermetallic Precipitates

Identification of intermetallic precipitates formed during re-solidification of brazed aluminium alloys

2006 ◽  
Vol 55 (2) ◽  
pp. 191-194 ◽  
Author(s):  
M DEHMAS ◽  
R VALDES ◽  
M LAFONT ◽  
J LACAZE ◽  
B VIGUIER
Keyword(s):  
Aluminium Alloys ◽  
Intermetallic Precipitates

Amorphization Kinetics of Zr (Cr,Fe)2 Under Ion Irradiation

1992 ◽  
Vol 279 ◽  
Author(s):  
A. T. Motta ◽  
L. M. Howe ◽  
P. R. Okamoto
Keyword(s):  
Neutron Irradiation ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Matrix Interface ◽  
Thin Foils ◽  
Intermetallic Precipitates ◽  
Kinetics Of

ABSTRACTThin foils of Zircaloy-4 were irradiated with 350 KeV 40Ar ions in the dual ion beam/HVEM facility at Argonne National Laboratory at 300 – 650 K. The irradiation-induced araorphization of the intermetallic precipitates Zr (Cr, Fe)2 and Zr2 (Ni, Fe) was studied in situ. For Zr (Cr,Fe)2 precipitates the dose-to-amorphization was found to increase exponentially with temperature, with a critical temperature of about 650 K. The amorphization morphology was shown to be homogeneous, with no preferential site for nucleation, in contrast to neutron-irradiation amorphization which started at the precipitate-matrix interface. For Zr2 (Ni,Fe) precipitates it was found that amorphization occurred at 550 K and 600 K, whereas in neutron irradiation no amorphization has been observed at those temperatures. The results are discussed in the context of the previous experimental results of neutron and electron irradiation and likely amorphization mechanisms are proposed.

scholarly journals New insights into microstructure of irradiated beryllium based on experiments and computer simulations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Klimenkov ◽  
P. Vladimirov ◽  
U. Jäntsch ◽  
V. Kuksenko ◽  
R. Rolli ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Gas Bubbles ◽  
Atomic Scale ◽  
Average Height ◽  
Secondary Phases ◽  
Atomistic Modelling ◽  
Transmission Electron ◽  
Intermetallic Precipitates ◽  
Diffusion Mechanisms ◽  
Small Bubbles

Abstract The microstructural response of beryllium after neutron irradiation at various temperatures (643–923 K) was systematically studied using analytical transmission electron microscope that together with outcomes from advanced atomistic modelling provides new insights in the mechanisms of microstructural changes in this material. The most prominent feature of microstructural modification is the formation of gas bubbles, which is revealed at all studied irradiation temperatures. Except for the lowest irradiation temperature, gas bubbles have the shape of thin hexagonal prisms with average height and diameter increasing with temperature. A high number density of small bubbles is observed within grains, while significantly larger bubbles are formed along high-angle grain boundaries (GB). Denuded zones (DZ) nearly free from bubbles are found along both high- and low-angle grain boundaries. Precipitations of secondary phases (mainly intermetallic Al-Fe-Be) were observed inside grains, along dislocation lines and at GBs. EDX analysis has revealed homogeneous segregation of chromium and iron along GBs. The observed features are discussed with respect to the available atomistic modelling results. In particular, we present a plausible reasoning for the abundant formation of gas bubbles on intermetallic precipitates, observation of various thickness of zones denuded in gas bubbles and precipitates, and their relation to the atomic scale diffusion mechanisms of solute-vacancy clusters.

scholarly journals The significance of microstructure heterogeneities on the fatigue thresholds of aluminum castings

2018 ◽  
Vol 165 ◽  
pp. 14005 ◽  
Author(s):  
Sascha Gerbe ◽  
Stephan Knorre ◽  
Ulrich Krupp ◽  
Wilhelm Michels
Keyword(s):  
Eutectic Silicon ◽  
Fatigue Behaviour ◽  
Fatigue Threshold ◽  
Fatigue Properties ◽  
Cast Aluminum ◽  
Aluminum Castings ◽  
Wide Range ◽  
Intermetallic Precipitates ◽  
In Series ◽  
Free Material

Industrial in-series aluminum castings contain a wide range of microstructural heterogeneities like differences in secondary dendrite arm spacing (SDAS), eutectic silicon and intermetallic precipitates of varying morphologies and diverse-shaped and-sized porosity. Regarding to technical and economic limitations, the complete elimination of them is hard to achieve, which requires conservative design, i.e., increased wall thicknesses to accommodate the failure tolerance. To improve the performance of cast aluminum products concerning safety and fatigue properties, the present work deals with the significance of such structures with respect to the threshold for crack propagation ΔKI,th under pure bending and the fatigue behaviour in the high-and very-high-cycle-fatigue regime (HCF and VHCF). Therefore, two automotive cast alloys taken from engine blocks (AlSi8Cu3) and cylinder heads (AlSi7Cu0.5Mg) and a gravity die cast set (AlSi7Mg0.3), either T6 conditioned or additionally hot isostatic pressed (HIP), were used. For in-series castings, two positions of maximal difference in cooling rate and respective microstructure were extracted. With this set of specimens, the significance of SDAS in interaction with (i) eutectic silicon regions, (ii) intermetallic precipitates in varying occurrence, (iii) the crystallographic orientation, and (iv) the porosity in correlation with the fatigue threshold is shown and compared with first results of fatigue damaging mechanisms in quasi pore-free material.

scholarly journals Data on a new beta titanium alloy system reinforced with superlattice intermetallic precipitates

Data in Brief ◽  
2018 ◽  
Vol 17 ◽  
pp. 863-869
Author(s):  
Alexander J. Knowles ◽  
Tea-Sung Jun ◽  
Ayan Bhowmik ◽  
Nicholas G. Jones ◽  
T. Ben Britton ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Alloy System ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Intermetallic Precipitates

Effect of Prior-Deformation on the Stability of the Intermetallic Precipitate in Zircaloy-2

1994 ◽  
Vol 373 ◽  
Author(s):  
Peter Y Huang ◽  
R.B. Adamson
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Cold Work ◽  
Mechanical Deformation ◽  
Black Dot ◽  
Irradiation Effects ◽  
Transmission Electron ◽  
Preferential Diffusion ◽  
Intermetallic Precipitates ◽  
Scanning Transmission ◽  
The Stability

AbstractBoth stress-relieved (SR) and recrystallized (RX) samples irradiated near 300°C tofluences between 1 and 9 x 1021 n/;cm2 (E>IMeV) were examined using analytical scanning transmission electron microscopy (STEM). The aim was to extend our knowledge of irradiation effects on microstructure by examining the effect of prior-cold-work on the dissolution of intermetallic precipitates in Zircaloy-2. Resulting from prior mechanical deformation and fast neutron irradiation, SR samples contain a high density of <a>-component, mixed <a+> line dislocations and “black dot” damage. On the other hand, RX samples contain mostly “black dot” damage. Pure <c>-dislocations are detected in the high fluence samples in RX materials. For identical irradiation conditions, different degrees of amorphization and dissolution are observed in RX and SR samples. Also, preferential diffusion of solute is observed to occur along <c>-dislocations. These results are discussed in terms of possible interactions between irradiation produced defects, precipitates and solutes.

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