Tribological Properties Of Lubricating Oil Containing Particles From Rice Husk Carbon/MoS₂ Composite

Carbon nanoparticle co-doped with sulfur and nitrogen?S,N-CN?were prepared from rice husk powder through a hydrothermal reaction in the present thesis.The composite particles?RHC/MoS₂?from rice husk carbon and molybdenum disulfide were produced by adding rice husk carbon in the process of synthesizing molybdenum disulfide.The surface modification of RHC/MoS₂ composites was carried out by using aminopropyl trimethoxysilane?ATS?as surface modifier in order to increase the dispersion of RHC/MoS₂ composites in base oil.The tribological properties of S,N-CN,RHC/MoS₂ and modified RHC/MoS₂ composites in lubricating oil were investigated.The tribological mechanism was analyzed by using X-ray photoelectron spectroscopy and Raman spectroscopy to analyze the worn surfaces.The tribological properties of S,N-CN in base oil were studied on UMT-2tribo-meter The results showed that when 0.1 wt%S,N-CN particles were dispersed in the pure base oil,the friction coefficient and wear rate were reduced by up to 16.6%and 75.9%,respectively.The friction reduction and wear resistance abilities of base oil containing S,N-CN were superior to those of pure base oil.The reasons can be attributed S,N-CN nanoparticles to be entered the ball-disc contact interface and tribo-chemical reactions to be occurred and formed tribofilm with metal surfide between S,N-CN nanoparticles and rubbing surfaces.The tribological properties of RHC/MoS₂ composite particles in base oil were studied on UMT-2 tribo-meter.The results showed that RHC/MoS₂ composite particles have better tribological properties than MoS₂.The results of SEM and Raman analysis showed that MoS₂ and RHC exhibit a synergistic effect,and the lubrication film was formed by RHC/MoS₂ composite particles.RHC/MoS₂ composite particles were modified by surface modifier ATS.The dispersion results showed that modified RHC/MoS₂ composite particles in the base oil exhibited a long term homogeneous phase without any noticeable precipitation.The results showed that the tribological properties of modified RHC/MoS₂ composite particles are improved.The wear mechanism is attributed to the fact that ATS can make the composites dispersed in base oill uniformly,which makes RHC/MoS₂participate in the formation of boundary lubrication film easily and reduce the aggravation of wear caused by particle agglomeration.On the other hand,ATS prevents the oxidation formation of MoO₃ from MoS₂,which improves the lubrication condition.