Comparative Study on Intergranular Segregation of Sulfur and Phosphorus Induced During Neutron Irradiation And Thermal Ageing in Vanadium-20 WT.% Titanium Alloys

1996 ◽  
Vol 439 ◽  
Author(s):  
T. E. Bloomer ◽  
D. Y. Lyu ◽  
J. Kameda
Keyword(s):  
Grain Boundary ◽  
Comparative Study ◽  
Titanium Alloys ◽  
Neutron Irradiation ◽  
Dynamic Interaction ◽  
Thermal Ageing ◽  
Vanadium Alloys ◽  
Impurity Segregation ◽  
Ti Alloys ◽  
Underlying Mechanisms

AbstractIntergranular impurity segregation induced during neutron irradiation (9.8 × 1024 n/mr at 438 °C) and thermal ageing has been studied in V-20 wt.% Ti alloys undoped, P doped and S doped all containing residual C and O. Neutron irradiation induced intergranular segregation and desegregation of S in undoped and S doped alloys, respectively. Thermal ageing resulted in a large increase in the S segregation in the undoped and S doped alloys. However, all unirradiated, aged and irradiated P doped alloys showed negligible S segregation. The vanadium alloys had smaller P segregation, compared to the S segregation in the undoped and S doped alloys. The irradiation and ageing enhanced the P segregation in a different fashion depending on the alloys. The grain boundary enrichment of C, O and Ti was reduced during the irradiation but promoted by the thermal ageing. The underlying mechanisms controlling intergranular impurity segregation caused by irradiation or thermal ageing are discussed in light of the impurity solubility change and dynamic interaction of defect and impurity fluxes.

Intergranular Fracture in Neutron Irradiated Vanadium-20 Wt.% Titanium Alloys Undoped and Doped with Phosphorus

1996 ◽  
Vol 458 ◽  
Author(s):  
J. Kameda ◽  
T. E. Bloomer ◽  
D. Y. Lyu
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Neutron Irradiation ◽  
Intergranular Fracture ◽  
Mixed Mode ◽  
Fracture Behavior ◽  
Testing Method ◽  
Ti Alloys ◽  
Microcrack Formation ◽  
Heterogeneous Formation

ABSTRACTThis paper presents the effect of neutron irradiation (9.8 × 1024 n/m2 at 438 °C) on the mechanical properties in V-20 wt.% Ti alloys undoped and doped with P using a small punch testing method. The same amount of neutron irradiation-induced hardening, that is almost temperature independent, was observed in undoped and P doped alloys. Neutron irradiation facilitated heterogeneous formation of grain boundary microcracks, not leading to specimen failure, in the undoped alloy. An irradiated undoped alloy showed ductility loss, that is not as much as expected from the easy microcrack formation due to a mixed mode of intergranular and transgranular cracking. Conversely, in the P doped alloy, intergranular microcracking was suppressed and low temperature ductility was improved by the irradiation. The intergranular fracture behavior controlling the ductility change is discussed in terms of the grain boundary composition and yield strength affected by the neutron irradiation.

Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

1971 ◽  
Vol 29 ◽  
pp. 122-123
Author(s):  
N. E. Paton ◽  
D. de Fontaine ◽  
J. C. Williams
Keyword(s):  
Electron Microscope ◽  
Titanium Alloys ◽  
Direct Observation ◽  
Dark Field ◽  
X Ray Diffraction ◽  
Resistivity Measurements ◽  
Selected Area Electron Diffraction ◽  
Ti Alloys ◽  
Thin Foils ◽  
Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

105 poster: Captopril and S-Nitrosocaptopril as Potent Radiosensitizers: Comparative Study and Underlying Mechanisms.

2010 ◽  
Vol 94 ◽  
pp. S41
Author(s):  
B. Jordan ◽  
J. Peeterbroeck ◽  
O. Karroum ◽  
C. Diepart ◽  
J. Magat ◽  
...  
Keyword(s):  
Comparative Study ◽  
Underlying Mechanisms

scholarly journals Dislocation–grain boundary interactions: recent advances on the underlying mechanisms studied via nanoindentation testing

2021 ◽  
Author(s):  
Farhan Javaid ◽  
Habib Pouriayevali ◽  
Karsten Durst
Keyword(s):  
Grain Boundary ◽  
Mechanical Response ◽  
Displacement Curve ◽  
Ambient Conditions ◽  
Recent Advances ◽  
Slip Transfer ◽  
Depth Analysis ◽  
Dislocation Interactions ◽  
Underlying Mechanisms ◽  
Insight Into

Abstract To comprehend the mechanical behavior of a polycrystalline material, an in-depth analysis of individual grain boundary (GB) and dislocation interactions is of prime importance. In the past decade, nanoindentation emerged as a powerful tool to study the local mechanical response in the vicinity of the GB. The improved instrumentation and test protocols allow to capture various GB–dislocation interactions during the nanoindentation in the form of strain bursts on the load–displacement curve. Moreover, the interaction of the plastic zone with the GB provides important insight into the dislocation transmission effects of distinct grain boundaries. Of great importance for the analysis and interpretation of the observed effects are microstructural investigations and computational approaches. This review paper focused on recent advances in the dislocation–GB interactions and underlying mechanisms studied via nanoindentation, which includes GB pop-in phenomenon, localized grain movement under ambient conditions, and an analysis of the slip transfer mechanism using theoretical treatments and simulations. Graphical abstract

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