Abstract With the increase in single cell area and number in a solid oxide fuel cell stack, the influence of interface contact resistance between cells and interconnects on stack performance becomes particularly significant. This work investigates Ni–Al intermetallic compounds with high oxidation resistance and electrical conductivity as a porous cathode contact layer (CL). The CL is successfully synthesized via in-situ reactive sintering of elemental Ni and Al powders on SUS430 (430) interconnect substrates at 900 °C for 2 h in argon, consisting mainly of NiAl and Ni₃Al phases. The CL/430 assembly is oxidized isothermally for 300 h at 750 °C in air, demonstrating a high oxidation resistance and stable interfacial area specific resistance (ASR) maintained in the range of 8.4-9.01 mΩcm2. Long-term testing up to 1000 h with 10 thermal cycles reveals that the interface remains intact, while ASR rises from 9.29 to 15.96 mΩ·cm². This increase is mainly attributed to the gradual growth of NiO on the porous CL, as well as to potential interface micro-cracking. The latter is induced by thermal stress buildup, which stems from the thermal expansion mismatch between the intermetallic compounds and SUS430.