SKM 2023 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 4: Thin Film Properties I
DS 4.5: Vortrag
Montag, 27. März 2023, 16:30–16:45, SCH A 316
Microstructure and mechanical properties of Ta-Al-B coatings — •Chun Hu1, Shuyao Lin1, Maximilian Podsednik2, Andreas Limbeck2, Nikola Koutná1, and Paul H. Mayrhofer1 — 1Institute of Materials Science and Technology,TU Wien,Getreidemarkt 9,Vienna,A-1060,Austria — 2Institute of Chemical Technologies and Analytics, TU Wien, A-1060 Wien, Austria
Alloying is a simple yet powerful tool to tune properties of hard coatings. Here we report stoichiometry, microstructure and hardness evolution of Al-alloyed TaB2-z coatings. Sputtering a stoichiometric TaB2 target results in sub-stoichiometric TaB1.23 with a mixed hexagonal-TaB2 (α-AlB2-type) and orthorhombic TaB structure. Co-sputtering an AlB2 target*with half the sputtering power density*increases the B content and strongly promotes the α-phase, while only little Al is incorporated (Ta0.997Al0.003B1.64). The coating shows a small grain size and the overall highest hardness. Further increasing the AlB2/TaB2 sputter ratio allows for B/Metal ratios of 1.97 and 2.29 with Al metal-fractions up to 48 at%. These coatings are single-α-phased with a smooth surface but gradually decreased hardness due to the increased AlB2-fraction. The structural evolutions are underpinned by ab initio calculations.