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Effect of Heating on the Microstructure of NiAl + CrB2 Coatings Deposited by Mechanical Embedding in a Ball Mill

Published online by Cambridge University Press:  09 September 2021

Maciej Szlezynger*
Affiliation:
Institute of Metallurgy and Materials Science Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow, Poland
Jerzy Morgiel
Affiliation:
Institute of Metallurgy and Materials Science Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow, Poland
Małgorzata Pomorska
Affiliation:
Institute of Metallurgy and Materials Science Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow, Poland
Łukasz Maj
Affiliation:
Institute of Metallurgy and Materials Science Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow, Poland
*
*Corresponding author: Maciej Szlezynger, E-mail: m.szlezynger@imim.pl
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Abstract

The thickness of NiAl + CrB2 coatings, produced by the mechanical embedding of powders, is limited due to the increasing brittleness of processed materials with milling time. Only the NiAl grain growth and resultant softening of the coating matrix could overcome this problem. Therefore, the effect of heating up to 750°C on the microstructure of NiAl + CrB2 coatings deposited in a ball mill rotating at 350 rpm was investigated through in situ TEM observations. The performed observations proved that defect annihilation starts at ~400°C in large intermetallic grains, which are first attached to the substrate. The growth in NiAl nanocrystallites forming most of the coating is activated only above ~600°C. The average crystallite size was measured to be 5, 14, and 19 nm at RT, 650°C, and 750°C, respectively. The first stage of nano-crystallite growth is relatively fast and connected with the reconstruction of crystallite boundaries using up the amorphous material accumulated in between them. The second stage is slower and involves the expansion of larger crystallites at the expense of smaller ones. The performed experiment proved that heating up to 750°C allows the microstructure recovery and grain coarsening of coatings to be activated.

Type
The XVIIth International Conference on Electron Microscopy (EM2020)
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of the Microscopy Society of America

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References

Awotunde, M, Ayodele, O, Adegbenjo, A, Okoro, A, Shongwe, M & Olubambi, P (2019). Nial intermetallic composites – a review of processing methods, reinforcements and mechanical properties. Int J Adv Manuf Technol 104, 17331747.CrossRefGoogle Scholar
Bonetti, E, Del Bianco, L, Pasquini, L & Sampaolesi, E (1999). Thermal evolution of ball milled nanocrystalline iron. NanoStruct Mater 12, 685688.CrossRefGoogle Scholar
Chen, T, Hampikian, JM & Thadhani, NN (1999). Synthesis and characterization of mechanically alloyed and shock-consolidated nanocrystalline NiAl intermetallic. Acta Mater 47, 25672579.CrossRefGoogle Scholar
Grunling, HW & Mannsmann, W (1993). Plasma sprayed thermal barrier coatings for industrial gas turbines: Morphology, processing and properties. J de Physique IV 3, 903912.Google Scholar
Joardar, J, Pabiz, SK, Fecht, HJ & Murty, BS (2002). Stability of nanocrystalline disordered NiAl synthesized by mechanical alloying. Philos Mag Lett 82, 469475.CrossRefGoogle Scholar
Joardar, J, Pabiz, SK & Murty, BS (2007). Milling criteria for the synthesis of nanocrystalline NiAl by mechanical alloying. J Alloys Compd 429, 204210.CrossRefGoogle Scholar
Malow, TR & Koch, CC (1997). Grain growth in nanocrystalline iron prepared by mechanical attrition. Acta Mater 45(5), 21772186.CrossRefGoogle Scholar
Poliarus, O, Morgiel, J, Bobrowski, P, Szlezynger, M, Umanskyi, O, Ukrainets, M, Maj, L & Kostenko, O (2019). Effect of powder preparation on the microstructure and wear of plasma-sprayed NiAl/CrB2 composite coatings. J Therm Spray Technol 28, 10391048.CrossRefGoogle Scholar
Stolof, NF & Sikka, VK (1996). Physical Metallurgy and Processing of Intermetallic Compounds. New York: Chapmann & Hall.CrossRefGoogle Scholar
Szlezynger, M, Morgiel, J, Maj, L, Poliarus, O & Czaja, P (2019). Microstructure of coatings on nickel and steel platelets obtained by co-milling with NiAl and CrB2 powders. Materials 12, 2593.CrossRefGoogle ScholarPubMed
Szlezynger, M, Morgiel, J, Rogal, Ł, Poliarus, O & Kurtyka, P (2018). Microstructure of NiAl+15 wt% CrB2 nano-crystalline composite coatings obtained through co-milling of NiAl and CrB2 powders. Compos Theory Pract 18(3), 149155.Google Scholar
Umanskyi, O, Poliarus, O, Ukrainets, M & Martsenyuk, I (2014). Effect of ZrB2, CrB2 and TiB2 additives on the tribological characteristics of NiAl-based gas-thermal coatings. Key Eng Mater 604, 2023.CrossRefGoogle Scholar
Wilson, BC, Hickman, JA & Fuchs, GE (2003). The effect of solution heat treatment on a single-crystal Ni-based superalloy. J Miner Met Mater Soc 55, 3540.CrossRefGoogle Scholar