Hits:

Indexed by:期刊论文

Date of Publication:2009-10-01

Journal:JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION

Included Journals:SCIE、EI、ISTIC、Scopus

Volume:24

Issue:5

Page Number:787-790

ISSN No.:1000-2413

Key Words:Ni-Al; diffusion couple; growth kinetics; intermediate phase; parabolic rate law

Abstract:Formation and growth of the intermediate phases in the Ni-Al diffusion couples prepared by pouring technique were investigated. Electron probe microanalysis, scanning electron microscopy and X-ray diffraction were used to characterize the product phases in the joints. The results show that two intermediate phases form in the sequence of NiAl(3) and Ni(2)Al(3) during solidification. After annealed, Ni(2)Al(3) and NiAl(3) still exist in the joints of the couples. The reasons for the formation of Ni(2)Al(3) and NiAl(3), as well as the absence of NiAl, Ni(5)Al(3) and Ni(3)Al were discussed, respectively. The growth kinetics of both product phase layers indicates that their growth obeys the parabolic rate law. The activation energies and frequency factors for NiAl(3) and Ni(2)Al(3) phases were also calculated according to the Arrhenius equation.