Microstructure and mechanical properties of a directionally solidified Mo-12Hf-24B alloy

Autor: I. Bogomol, V. Bolbut, Petro Loboda, Manja Krüger
Rok vydání: 2018
Předmět:
Zdroj: Journal of Alloys and Compounds. 735:2324-2330
ISSN: 0925-8388
DOI: 10.1016/j.jallcom.2017.11.352
Popis: In the present paper we report on a new Mo-12Hf-24B (in at. %) alloy which was processed by crucible-free zone melting (ZM) from cold pressed elemental powders. The alloy was solidified using crystallization rates of 90 mm/h, 100 mm/h and 110 mm/h. SEM investigations of the zone molten alloys showed well-aligned arrangements of the microstructural constituents. XRD analyses revealed the following phases: MoSS, Mo2B, HfB and a new phase, which is provisionally indicated as Mo2HfBx. The phases Mo2B and Mo2HfBx have a preferred crystallographic orientation parallel to the growth direction. High temperature compression creep strength at about 1100 °C was evaluated and compared with the commonly used Ni-based superalloys CMSX-4 and CMSX-10 as well as a directionally solidified Mo-Si-B materials. In comparison to the reference alloys, the creep resistance of ZM Mo-Hf-B materials was found to be substantially improved due to the construction and anisotropic arrangement of the incorporated compound phases in these Mo-based alloy.
Databáze: OpenAIRE