Book/Report

FZJ-2018-00509

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Metallographic investigations of group vb metal hydrides : Part 1: $\beta$-phase melting and solidification phenomena in the niobium-hydrogen system Part 2: Techniques for the metallographic examination of niobium-, tantalum- and vanadium-hydrides

Schober, T.FZJ* ; Linke, U.FZJ* ; Wenzl, H.FZJ*

1975
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/16591

Report No.: Juel-1240

Abstract: $\underline{Abstract (Part I)}$ The morphology of the decomposition and formation (or the melting and solidification in the lattice gas description) of the ordered NbH $\beta$-phase is investigated with polarized light and interference contrast techniques. Melting occurs in the absence of temperature gradients by the growth of drop lets of the liquid phase d nucleated at the domain boundaries. Solidification of the $\alpha'$-phase involves the formation of single-domain $\beta$-phase plates, subsequent repeated twinning and the growth of "elastic closure domains". The solidus and liquidus lines of the $\beta \rightarrow \alpha'$ transformation are determined in the range from 70 to 95 at, % H/Nb where the transition temperatures vary from 84 $^\circ$C (triple line of $\alpha$-, $\alpha$'- and $\beta$-phase) to 145 $^\circ$C. $\underline{Abstract (Part II)}$ Techniques for the metallographic examination of Nb, Ta and V-hydride specimens are presented. Special sampIe mounting procedures, as well as a heating and a cooling stage suitable for hydride investigations are described. The application of polarized light observations and Nomarski interference contrast to the study of hydrides is discussed. Some examples of micrographs of Nb, Ta or V-hydrides are given.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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