Performance Requirements For Spark Plugs

The main requirements for spark plugs are thermal characteristics, tensile strength, heat resistance, conductivity, insulation strength, sealing performance, and corrosion resistance.
The spark plug must be heat-resistant, and the part that it is screwed into should be placed in a crucible electric furnace or muffle electric furnace that has been heated to a temperature of 700 ℃ for 10 minutes, and then cooled in air. There should be no cracking or seed cracking on the surface of the insulator .
Spark plug sealing performance requirements: After conducting a heat resistance test, the air leakage rate shall not exceed 40cm3 per minute at a pressure difference of 1MPa (if the central electrode adhesive is made of conductor sealing material, the air leakage rate shall not exceed 5cm2 per minute) .
The spark plug insulator assembly should be able to withstand a power frequency (50Hz) voltage of 2200vV (effective value) for 30 seconds of testing .
Material: The conductivity of the center electrode and side electrode of the spark plug depends on the contact between the electrode and the mixture, so the electrode has extremely high requirements for corrosion resistance. At the same time, the temperature during combustion is extremely high, and the electrode material requires high heat resistance. Therefore, many spark plugs use nickel manganese alloy. To improve heat resistance, some spark plugs also use nickel clad copper material. Copper gaskets not only have thermal conductivity, but also serve as seals. The insulator is made of high alumina ceramic [3].