Skip to main content
padlock icon - secure page this page is secure

Open Access Exploring Lattice Defects in Palladium and its Alloys Using Dissolved Hydrogen

Download Article:
 Download
(HTML 56.2 kb)
 
or
 Download
(PDF 623.5 kb)
 
The first part of this paper, published in the July issue of this Journal, described the combination of physical metallurgical techniques and hydrogen solubilities used to help in characterising defects in palladium (Pd) and Pd alloys. In this second part, the solubilities of hydrogen (H2) in internally oxidised Pd alloys are discussed. Internal oxidation, for example of a palladium-aluminium alloy, results in the formation of small alumina precipitates within the Pd matrix. Dissolved H in the alloy is strongly trapped at the metal/oxide interface. This can be detected by deviations in H solubility from that expected for Pd. Hydrogen in Pd and its alloys has been modelled mathematically as the occupation by H atoms of interstitial sites within fixed metal sublattices. However, recently it has been realised that at moderately high temperatures and H2 pressures some alloy lattices are not fixed, as the dissolved H promotes metal atom diffusion. This results in phase separation in some alloys, for example (Pd + Pt + H), according to a ternary equilibrium. The dissolved H can be removed from such alloys at low temperatures allowing the metastable, phase-separated alloy lattices to be characterised via measurements of H2 solubilities and suitable physical metallurgical techniques.

33 References.

No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: October 1, 2001

More about this publication?
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more