Work

Evaluation of Sintered Powder Metallurgy Fe-Cr Alloys as Metallic Interconnects for Solid Oxide Fuel Cell Applications

Year: 2025

Type: article

Abstract: Metallic interconnects are key components in planar solid oxide fuel cell (SOFC) stacks. In the present study, we evaluated four Fe-Cr powder metallurgy (PM) alloy specimens, obtained from a domestic manufacturer, at nominal compositions (in wt%) of 5% Fe-95% Cr, 30% Fe-70% Cr, 50% Fe-50% Cr, and 78% Fe-22% Cr. These specimens were tested and evaluated for use in SOFC stack applications. The verification items included coefficient of thermal expansion measurements, high-temperature oxidation resistance and weight gain tests, mechanical strength tests, high-temperature sealant bonding and leakage rate measurements, and high-temperature electrical property (i.e., area-specific resistance) measurements. In addition, the specimens’ microstructures and elemental compositions were observed and analyzed. The test results indicate that the Fe content of the Fe-Cr powder metallurgy alloys influences various properties, while Cr also plays a significant role in high-temperature oxidation resistance. Among the four alloy specimens, the 78Fe-Cr alloy exhibited all of the aforementioned advantages, including a suitable coefficient of thermal expansion of 12.4 × 10−6/°C, excellent high-temperature oxidation resistance, a thermal weight-gain rate of 5.31 × 10−14 g2/cm4·s, a remarkably low high-temperature area-specific resistance of 7.04 mΩ·cm2, and superior bonding and interfacial stability with the GC9 glass–ceramic sealant, achieving a very low leakage rate of 3.47 × 10−6 mbar·l/s/cm. These results indicate that the 78Fe-Cr powder metallurgy alloy performs excellently and is the most promising candidate for metallic interconnects in SOFC stack applications.

Source: Metals

DOI: 10.3390/met15121370

Authors: Chien-Kuo Liu, Wei-Ja Shong

Institution: National Atomic Research Institute

Language: English

Topic: Advancements in Solid Oxide Fuel Cells

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,137