Synthesis of silver nanoparticles integrated molybdenum disulfide nanoparticles and fundamental understanding the behavior of silver-molybdenum disulfide nanoparticles based hybrid system

This work is designed to study tribological properties of silver nanoparticles integrated molybdenum disulfide nanoparticles based hybrid system. The research work is based on the synthesis of silver nanoparticles and their integration in the molybdenum disulfide nanoparticles matrix (Ag-MoS 2 hybrid systems) and the fundamental understanding of their tribological behaviors. First of all, silver is a relatively soft material and exhibits low shear strength; it has good embeddability which allows Ag nanoparticles to embed wear particles into a softer lining. Secondly, MoS2 reacts with silver at higher temperatures to form various phases of silver molybdates which are effective lubricants for high temperature applications. Therefore, with a small addition of Ag nanoparticles to molybdenum sulfide, Ag-MoS 2 nanoparticles based hybrid systems can reduce the coefficient of friction (COF), prolong the life of traditional MoS2 nanoparticles even through high temperatures, and increase the strength of MoS2 tribofilms.;X-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM), and particle size analysis were used to examine structural properties, silver content, particle size, and particle size distribution. Friction and wear properties were studied by pin-on-disc, and analysis of wear tracks were characterized by scanning electron microscopy (SEM) and EDS techniques. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results confirmed that silver molybdates were formed at higher temperatures (around 450-600 °C) and are known to be good antifriction agents at higher temperatures.;The Pin-on-disk experiments were conducted at room temperature for Ag-MoS 2 in comparison with MoS2 nanoparticles, and tribofilms were analyzed. Tribological study at room temperature showed a significant enhancement in performance due to Ag integrated into MoS2 nanoparticles. Further tribological testing at higher temperature will be performed in the future. In summary, Ag-MoS2 alloyed nanoparticles were synthesized successfully with varying Ag concentrations and showed formation of silver molybdate phases. Ag-MoS2 nanoparticle alloys showed better tribological properties over its counterparts. Future studies will focus on a fundamental study of Ag-MoS2 and other metallic candidates at room temperatures and higher.