Microscopic Tribology of ADC12 Alloy Under Lubricant Containing ZDDP and MoDTC Using In Situ AFM

Tribofilm growth, friction and wear behaviour are not well understood for non-ferrous alloys under lubricated contacts in the presence of combination of zinc dialkyl dithiophosphates (ZDDPs) and molybdenum dithiocarbamate (MoDTC) lubricant additives. This study is focused on the growth of tribofilms and tribological properties monitored in situ using an atomic force microscopy (AFM)-based approach. Experiments are performed on the Al matrix and Si phase of Al-Si alloy (ADC12) in the presence of ZDDP and MoDTC at high temperature (110 degrees C). The addition of MoDTC in ZDDP results in relatively thinner tribofilm over Si phase in comparison to ZDDP alone when sliding is performed simultaneously over the Al matrix and Si phase. The antiwear properties are found to be significantly improved when sliding only on the Al matrix. However, friction reduction is observed in both cases.