Anelastic relaxation due to hydrogen in Ti–35Nb–7Zr–5Ta alloy

Anelastic Relaxation of Metallic Glasses

Anelastic relaxation processes due oxygen in Nb–3.1 at.% Ti alloys

In the last 50 years several studies have been made to understand the relaxation mechanisms of the heavy interstitial atoms present in transition metals and their alloys. Internal friction measurements have been carried out in a Nb–Ti alloy containing 3.1 at.% of Ti produced by the Materials Department of Chemical Engineering Faculty of Lorena (Brazil), with several quantities of oxygen in soli...

Anelastic Relaxation of Protonic Defects in M3+-Doped BaCeO3

When perovskite-structured BaCe03 is doped with M ~ + ions (e.g., ~ d ~ + , Gd3+,yb33 that substitute on ce4+ sites, oxygen-ion vacancies are created for charge compensation. However, when treated in water vapor, the vacancies are replaced by protons, which take the form of OH' ions. This treatment makes the materials a good protonic conductor. Questions about the defect structure of the proton...

Hydrogen relaxation in lutetium

2014 The internal friction and the dynamic modulus have been measured between 4.2 and 470 K in the system 03B1-LuH(D)x, with x = 0 to 0.2. In well annealed specimens, an (H)-peak is observed at 215-225 K, which has a linearly x-dependent amplitude and exhibits an isotope effect on its activation energy and relaxation time. It is attributed to a Snoek-like relaxation of H-H pairs reorienting in ...

Dendrite fragmentation in alloy solidification due to sidearm pinch-off.

Dendrite sidebranch detachment is an important fragmentation mechanism during the solidification of alloys. The detachment occurs at the junction between a sidearm and its parent stem. While this pinching process is driven by capillarity, the presence of solidification opposes the instability. Using a simple numerical model of a single sidearm, we are able to capture the essential dynamics of d...