Lean combustion is one of the effective methods to improve the efficiency of engine. High energy ignition can significantly enhance the stability of lean combustion, attracting widespread attention in engine applications, particularly in GDI engines. However, higher ignition energy accelerates the erosion rate of spark plug electrodes, thereby shortening their lifespan. Currently, there is no established quantitative evaluation method for assessing the erosion resistance of spark plug electrodes with a high energy ignition system. Thus, developing a reliable and rapid testing method to evaluate the erosion resistance of spark plug electrode materials is crucial and urgent. Such a method would facilitate the selection of superior electrode materials, ultimately improving the erosion resistance of spark plugs and extending their lifespan.
This study developed an innovative erosion testing system for spark plug center electrode materials based on a self-made high energy ignition device, which igniton ene rgy is as high as 600 mJ and proposed corresponding evaluation methods. Using this system, eight different noble metal alloy materials, three iridium-based alloys and five platinum-based alloys, were tested as either positive or negative electrodes to simulate anode ignition or cathode ignition systems. Three evaluation methods, in terms of ignition gap method, electrode projection area method, and electrode volume method, were employed to assess and analyze the erosion of the electrode materials.
The results indicate that the testing system established in this study enables rapid detection of the erosion resistance of spark plug electrode materials. When the spark plug center electrode was connected to the cathode of the device, its erosion rate was significantly higher than when connected to the anode. This suggests that connecting the center electrode to the cathode can accelerate electrode material erosion and shorten the testing cycle. Compared to the other two methods, the electrode volume method demonstrated more stable measurement accuracy, making it a more reliable approach for evaluating the erosion resistance of spark plug electrodes. Under both anode ignition and cathode ignition test conditions, iridium-based alloys exhibited lower erosion rates than platinum-based alloys, indicating that iridium-based alloys possess superior erosion resistance.