Published July 14, 2008 | Version v1
Journal article

Effects of alloying elements on dendritic segregation in iridium alloys

  • 1. Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States)
  • 2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)
  • 3. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

Description

The effects of alloying elements on dendritic segregation in Ir alloys were studied by Auger Electron Spectroscopy (AES). The addition of 10 at.% Nb induces significant segregation of carbon and thorium to dendritic interfaces. The addition of 5 at.% Zr to the Ir alloy leads to the formation of an Ir3Zr intermetallic phase, which results in less dendritic segregation of carbon and thorium. This dendritic segregation appears to be linked to the severe cracking observed in the Ir-Nb alloy, but not in the Ir-Zr alloy, after casting and heat treatment. The mechanism for the dendritic segregation was discussed by consideration of the solidification process and the change of carbon solubility in Ir by Zr addition

Availability note (English)

Available from http://dx.doi.org/10.1016/j.jallcom.2007.04.252

Additional details

Identifiers

DOI
10.1016/j.jallcom.2007.04.252;
PII
S0925-8388(07)01079-1;

Publishing Information

Journal Title
Journal of Alloys and Compounds
Journal Volume
459
Journal Issue
1-2
Journal Page Range
p. 130-134
ISSN
0925-8388
CODEN
JALCEU

Optional Information

Copyright
Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.