Authors: | Tillmann, Wolfgang Wojarski, Lukas Stangier, Dominic Manka, Matthias Timmer, Christian |
Title: | Application of the eutectic high entropy alloy Nb0.73CoCrFeNi2.1 for high temperature joints |
Language (ISO): | en |
Abstract: | The eutectic high entropy alloy Nb0.73CoCrFeNi2.1 was manufactured by means of arc smelting and the obtained ingots were cut into 300-μm-thick foils, which were used as filler alloys to braze Crofer 22 APU to Hf-metallized yttria-stabilized zirconia (3YSZ). The brazing process was conducted in a vacuum furnace at 1200 °C for 5 min at a vacuum of 4.3·10–4 mbar. In order to minimize the intense diffusion and erosion of the steel substrate, a heating and cooling rate of 50 K/min was applied. Sound joints without any pores or flaws were obtained. The microstructure of the joints consisted of an HfO2 reaction layer at the ceramic interface and the same eutectic structure consisting of a Laves phase and a solid solution that was already detected in the smelted foil. The average hardness of the microstructure in the joint seam amounted to 352 ± 17 HV0.01 and the joints reached strength values up to 97 ± 7 MPa while the fracture area was always located at the ceramic interface in the HfO2 layer. Comparable joints, with AgCuTi3 as filler metal, brazed at 920 °C, only reached a shear strength of ~ 52 ± 2 MPa. |
Subject Headings: | Vacuum brazing High entropy alloy (HEA) Eutetic high entropy alloy (EHEA) Solid oxygen fuel cells SOFC |
Subject Headings (RSWK): | Hartlöten Hochentropielegierung Festoxidbrennstoffzelle |
URI: | http://hdl.handle.net/2003/40095 http://dx.doi.org/10.17877/DE290R-21972 |
Issue Date: | 2020-07-06 |
Rights link: | https://creativecommons.org/licenses/by/4.0/ |
Appears in Collections: | Lehrstuhl für Werkstofftechnologie |
Files in This Item:
File | Description | Size | Format | |
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Tillmann2020_Article_ApplicationOfTheEutecticHighEn.pdf | DNB | 1.59 MB | Adobe PDF | View/Open |
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