RT Journal Article
T1 Molybdeno-Aluminizing of Powder Metallurgy and Wrought Ti and Ti-6Al-4Valloys by Pack Cementation process
A1 Tsipas, Sophia Alexandra
A1 Gordo Odériz, Elena
AB Wear and high temperature oxidation resistance of some titanium-based alloys needs to be enhanced, and this can beeffectively accomplished by surface treatment. Molybdenizing is a surface treatment where molybdenum is introducedinto the surface of titanium alloys causing the formation of wear-resistant surface layers containing molybdenum, whilealuminizing of titanium-based alloys has been reported to improve their high temperature oxidation properties. Whereaspack cementation and other surface modification methods have been used for molybdenizing or aluminizing of wroughtand/or cast pure titanium and titanium alloys, such surface treatments have not been reported on titanium alloys producedby powder metallurgy (PM). Also a critical understanding of the process parameters for simultaneous one stepmolybdeno-aluminizing of titanium alloys by pack cementation and the predominant mechanism for this process havenot been reported. The current research work describes the surface modification of titanium and Ti-6Al-4V prepared byPM by molybdeno-aluminizing and analyzes thermodynamic aspects of the deposition process. Similar coatings are alsodeposited to wrought Ti-6Al-4V and compared. Characterization of the coatings was carried out using scanning electronmicroscopy and x-ray diffraction. For both titanium and Ti-6Al-4V, the use of a powder pack containing ammoniumchloride as activator leads to the deposition of molybdenum and aluminium into the surface but also introduces nitrogencausing the formation of a thin titanium nitride layer. In addition, various titanium aluminides and mixed titanium aluminiumnitrides are formed. The appropriate conditions for molybdeno-aluminizing as well as the phases expected to beformed were successfully determined by thermodynamic equilibrium calculations.
PB Elsevier
SN 1044-5803
YR 2016
FD 2016
LK https://hdl.handle.net/10016/23254
UL https://hdl.handle.net/10016/23254
LA eng
NO El artículo está disponible online en la web del editor (Elsevier) desde el 23 de junio de 2016.
NO Regional Government of Madridthrough the project S2013/MIT-2862 (MULTIMAT-CHALLENGE-CM), and by theMinistry of Economy and Competitiveness of Spain through the project MAT2012/38650-C02-01
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RD 27 jul. 2024