The most basic requirements for penetration into the combustor electrode are resistance to ablation (galvanic and chemical attack) and good thermal conductivity.
With the development of material science and process technology, the electrode materials have experienced the evolution of iron, nickel, nickel-based alloys, nickel-copper composites, and precious metals. Nickel-based alloys are most commonly used today. In general, pure metals are superior to alloys in their thermal conductivity, but the chemical corrosion reaction of pure metals, such as nickel, on the combustion gases and the solid deposits they form is more sensitive than the alloy. Therefore, nickel-based electrode materials used to add elements such as chromium, manganese, silicon, chromium to improve the anti-corrosion ability, manganese and silicon to improve chemical resistance, especially for the most harmful sulfur oxides corrosion resistance. Nickel-based alloys are inferior to copper in their thermal conductivity. The use of a copper core and the appearance of a nickel-based alloy (or other precious metal alloy) greatly improves the thermal conductivity of the electrode.
Domestic spark plug model suffix C represents the center of the copper core electrode, CC on behalf of double copper core electrode.