TY - JOUR
T1 - Rapid solidification and metastable phase formation during surface modifications of composite Al-Cr cathodes exposed to cathodic arc plasma
AU - Golizadeh Najafabadi, Mehran
AU - Mendez Martin, Francisca
AU - Wurster, Stefan
AU - Mogeritsch, Johann
AU - Kharicha, Abdellah
AU - Kolozsvári, Szilárd
AU - Mitterer, Christian
AU - Franz, Robert
N1 - Publisher Copyright:
© 2021
PY - 2021/12/20
Y1 - 2021/12/20
N2 - A combination of both conventional and advanced high-resolution characterization techniques was applied to study the modified layers on the surface of three composite Al-Cr arc cathodes with identical nominal composition of Al-50 at.% Cr but varying powder grain sizes. The results revealed that the modified layers consist mainly of metastable phases such as Cr solid solution, high temperature cubic Al 8Cr 5, supersaturated Al solid solution, and icosahedral quasicrystal. The metastable phase formation indicates that high cooling rates were involved during the solidification of molten material produced in the arc craters during cathode spot events. The average cooling rate was estimated to be 10 6 K/s based on secondary dendrite arm spacing measurements and supporting phase-field based simulations. The formation mechanisms of the modified layers are discussed based on the obtained results and the current literature.
AB - A combination of both conventional and advanced high-resolution characterization techniques was applied to study the modified layers on the surface of three composite Al-Cr arc cathodes with identical nominal composition of Al-50 at.% Cr but varying powder grain sizes. The results revealed that the modified layers consist mainly of metastable phases such as Cr solid solution, high temperature cubic Al 8Cr 5, supersaturated Al solid solution, and icosahedral quasicrystal. The metastable phase formation indicates that high cooling rates were involved during the solidification of molten material produced in the arc craters during cathode spot events. The average cooling rate was estimated to be 10 6 K/s based on secondary dendrite arm spacing measurements and supporting phase-field based simulations. The formation mechanisms of the modified layers are discussed based on the obtained results and the current literature.
UR - http://www.scopus.com/inward/record.url?scp=85107706007&partnerID=8YFLogxK
U2 - 10.1016/j.jmst.2021.03.059
DO - 10.1016/j.jmst.2021.03.059
M3 - Article
SN - 1005-0302
VL - 94:2021
SP - 147
EP - 163
JO - JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
JF - JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
IS - 20 December
ER -