The Study on Antiwear Performance for Al-Si Alloys with ZDDP-free Engine Oil

摘要

Recently, the amount of phosphorus and ash in automobile engine oil has been reduced to avoid the deterioration in after treatment devices for exhaust gas such as catalyst and diesel particulate filter. In addition, non-ferrous materials such as Al-Si alloys have been used in both engine and transmission to reduce its weight considering fuel economy. Therefore, suitable engine oil formulation is required to obtain same anti-wear performance for Al-Si alloys as for ferrous material. According to these backgrounds, the authors have studied the influence of the amount of zinc dialkyl dithiophosphate (ZDDP), which is widely used as anti-wear additives in engine oil, and the effect of non-ash additives on anti-wear performance on Al-Si alloys. In wear tests, it was observed that wear width increased as ZDDP decreased from the commercially available engine oil. On the other hand, non-ash additives such as sulphur compounds show good anti-wear performance. Though ZDDP plays a key role for anti-wear performance of Al-Si alloys, it was found that non-ash additives can be used as an anti-wear additive to replace ZDDP.