Abstract
The halide-activated pack cementation method was utilized to deposit a suitable coating on TiAl to ensure its oxidation resistance. TiAl alloys were coated by two different pack cementation processes with simple aluminide coating and Cr-modified aluminide coating. The coatings formed on the TiAl alloyed with Nb and Cr were thicker and tougher than those formed on the non-alloyed TiAl. The TiAl 3 layer formed on the TiAl alloyed with Nb and Cr had much better cyclic oxidation resistance than that formed on the non-alloyed TiAl. This is attributed to a change in the crystal structure of the TiAl 3 from the brittle tetragonal DO 22 to the ductile cubic LI 2 by addition of a small amount of Cr and Nb. The Cr-modified aluminide coating on the TiAl alloyed with Nb and Cr exhibited excellent cyclic oxidation resistance due to formation of the Al 67Ti 25Cr 8 phase as the coating layer. (C) 2000 Published by Elsevier Science S.A. All rights reserved.
Original language | English |
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Pages (from-to) | 117-123 |
Number of pages | 7 |
Journal | Surface and Coatings Technology |
Volume | 132 |
Issue number | 2-3 |
DOIs | |
State | Published - Oct 2000 |
Externally published | Yes |
Funding
The National Natural Science Foundation of China and the Korea Science and Engineering Foundation are acknowledged for financial support.
Funders | Funder number |
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National Natural Science Foundation of China | |
Korea Science and Engineering Foundation |
Keywords
- Aluminide coatings
- Pack cementation
- TiAl