Gorokhovsky V., Oxidation resistant, Cr retaining, electrically conductive coatings on metallic alloys for SOFC interconnects

Final Report, DOE Award Number: DE-FC26-04NT42225, December 2, 2008, Bozeman MT USA, pgs. 48.
ABSTRACT:
This report describes significant results from an on-going, collaborative effort to enable
the use of inexpensive metallic alloys as interconnects in planar solid oxide fuel cells (SOFCs)
through the use of advanced coating technologies. Arcomac Surface Engineering, LLC, under
the leadership of Dr. Vladimir Gorokhovsky, is investigating filtered-arc and filtered-arc plasmaassisted
hybrid coating deposition technologies to promote oxidation resistance, eliminate Cr
volatility, and stabilize the electrical conductivity of both standard and specialty steel alloys of
interest for SOFC metallic interconnect (IC) applications. Arcomac has successfully developed
technologies and processes to deposit coatings with excellent adhesion, which have demonstrated
a substantial increase in high temperature oxidation resistance, stabilization of low Area Specific
Resistance values and significantly decrease Cr volatility. An extensive matrix of deposition
processes, coating compositions and architectures was evaluated. Technical performance of
coated and uncoated sample coupons during exposures to SOFC interconnect-relevant conditions
is discussed, and promising future directions are considered. Cost analyses have been prepared
based on assessment of plasma processing parameters, which demonstrate the feasibility of the
proposed surface engineering process for SOFC metallic IC applications.