The drive for high efficiency and low emissions in large gas engines leads to extreme conditions in the combustion chamber in terms of pressure and temperature of the lean air-fuel mixture and thus to high wear of spark plug electrodes. Traditional rare-metal materials used in spark plugs are expensive and are reaching their limits in terms of wear resilience, leading to the search for alternative materials to increase maintenance intervals and – costs, as well as engine reliability.

Advanced ceramics have emerged as a promising alternative due to their high thermal stability, excellent oxidation and corrosion resistance, and lower raw material costs compared to rare metals. However, the required high electrical conductivity poses a significant limitation for the use of ceramic materials. Additionally, the inherent brittleness of ceramics presents a challenge to their applicability, as mechanical stresses during manufacturing, handling, or service may cause fracture. The joining process of ceramic electrodes to metal counterparts is also a critical step for the production of reliable spark plugs.

This work presents a material selection study focusing on potential joining methods, and the thermo-mechanical as well as oxidation behavior of the selected materials. Promising results for different ceramic electrode materials under laboratory conditions, together with corresponding wear mechanisms, are shown. Overall, this research offers insights into the potential of advanced ceramics as spark plug electrode materials, highlighting the need of further investigation to ensure their reliability under various operating conditions.