Microstructure and Oxidation Performance of TiAl-(Cr, Nb, Ta) Coatings Fabricated by Warm Spray and High-Velocity Oxy-Fuel Spraying
Judyta Sienkiewicz , Seiji Kuroda , Hideyuki Murakami , Hiroshi Araki , Maciej Giżyński , Krzysztof Kurzydłowski
AbstractTo improve the oxidation resistance of near atitanium alloy IMI834, TiAl-(Cr, Nb, Ta) coatings were deposited by applying high-velocity oxy-fuel (HVOF) and warm spray (WS). Comparison was made in terms of microstructure, surface morphology as well as isothermal and cyclic oxidation behaviors in the air at 750 _C up to 100 h and 100 cycles, respectively. The results show that smoother and less oxidized coatings were deposited by warm spraying. The microstructure of all coatings underwent an appreciable change during the oxidation tests, as in as-sprayed state it occurred in the nonequilibrium state. It was revealed that a small difference in the initial oxidation between the two spraying processes as well as microstructure, the level of porosity and surface roughness significantly influences the oxidation kinetics of the sprayed coatings at high temperature, which should affect the service lifetime as an oxidation-resistant layer for potential applications. After exposure at 750 _C in air, rutile TiO2 was found in addition to a-Al2O3 in the oxide scale formed on the HVOF and warm sprayed coatings. However, isothermal and cyclic oxidation tests of all WS TiAl-(Cr, Nb, Ta) coatings showed improved oxidation resistance of IMI 834 as well as good adherence to the substrate alloy.
|Journal series||Journal of Thermal Spray Technology, ISSN 1059-9630, e-ISSN 1544-1016, (N/A 140 pkt)|
|Publication size in sheets||0.8|
|Keywords in English||coatings for engine components, high-temperature oxidation, interlayers, spray forming|
|ASJC Classification||; ;|
|Internal identifier||ROC 19-20|
|Score||= 140.0, 12-02-2020, ArticleFromJournal|
|Publication indicators||: 2018 = 1.087; : 2018 = 2.129 (2) - 2018=2.074 (5)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.