The influence of carbon on the resistivity recovery of proton irradiated Fe–11at.% Cr alloys

AbstractThe effect of carbon on the point defect migration properties in Fe–Cr alloys with a concentration of 11 at.% Cr is studied by means of resistivity recovery measurements after low temperature proton irradiation. The presence of carbon mainly affects features of the resistivity recovery spectra in the temperature ranges of (a) 150–200K, which are linked to self-interstitial defects, and (b) 400–500K, which are probably due to vacancy and vacancy-carbon complexes. The experimental results are discussed in terms of the possible interactions of carbon with radiation defects and its influence on solute atom re-ordering

Phase stability of Fe-5at%Cr and Fe-10at%Cr films under Fe+ ion irradiation

This work is within the objective of understanding the effects caused to Fe–Cr alloys by fast Fe ion irradiation. As the penetration length of Fe ion is of the order of hundreds of nanometers, 70 nm Fe-5at%C and Fe-10at%Cr films were irradiated at room temperature with 490 keV Fe+ ions at increasing fluence corresponding to a maximum damage of 50 displacements per atom (dpa). In Fe-5at%Cr alloy the Cr solute concentration remains unaltered even after a damage of 50 dpa. In the 10at%Cr the Cr solute concentration is reduced, with the increase of damage, asymptotically to a value of 7.2 at%

Studies of the precipitation process by small angle neutron scattering.

Small Angle Neutron Scattering (SANS) is a unique tool in the study of the precipitation phenomena. The size, shape, number density, volume fraction and chemical composition of the precipitates can be unambiguously determined and the kinetic process can be investigated by using samples that have undergone different heat treatments or by ‘’in situ” experiments. Systems exhibiting slow kinetics and low precipitate phase concentration (SiO2 precipitates in Si), fast kinetics for which low temperature experiments are required to ‘’freeze” the precipitate structure (Al-Zn) and ‘’in situ” experiments (Al-Li) will be discussed. The experimental results are interpreted by kinetic models which describe the precipitation process in these diverse growth conditions

Effects of Spallation Neutron Irradiation on Single Crystals of Iron, Nickel, Niobium And Stainless Steel

Single crystals of Iron, Nickel, Niobium and Stainless Steel (SS316) subjected to prolonged neutron irradiation in the Los Alamos Spallation Source for a period of one year have been studied using both small angle, and single crystal neutron diffraction. Small Angle Scattering show no evidence of any large radiation induced inhomogeneities in the pure metals, while regions of ~ 65 Å diameter are found in the irradiated SS316. Combining the s.a.s. measurements with the single crystal diffraction data these regions are attributed to the formation of coherent precipitates of Ni-Cr. However, a low concentration of point defects (<2.5 at %) is introduced in all the materials by the irradiation process. No significant radiation induced dilatation of the lattice is found in any of the materials. © 1991 Gordon and Breach. S.A

The use of neutron reflectivity in determining the structure of a platinum-carbon multi-layer

The neutron reflectivity from three platinum-carbon bilayers on a silicon substrate has been measured using θ-2θ scans. The thicknesses and densities of the layers are determined and also the nature of the multi-layer-substrate interface is deduced. This is accomplished by modelling the reflectivities of different multi-layer structures and comparing them to the experimental data