Study on lubricating mechanisms of La(OH)₃ nanocluster modified by compound containing nitrogen in liquid paraffin

In this paper, the tribological properties of La(OH)₃ nanocluster modified by compound containing nitrogen as additive in liquid paraffin were investigated using four-ball machine. The results show that La(OH)₃ nanocluster modified by compound containing nitrogen as additive in liquid paraffin has high load-carrying capacity, good antiwear and friction reduction properties. The lubricating mechanisms were studied by using EPM-810Q model electron probe microanalyzer (EPMA) and PHI-5702 multi-technique surface X-ray photoelectron spectrometer (XPS). The results show that the boundary film on the worn surface is made of physically adsorbing film (N-containing organic compound) and tribochemical reaction film (lanthanum oxide). The physically adsorbing film and tribochemical reaction film formed during friction contributed to good tribological properties of La(OH)₃ nanocluster modified by compound containing nitrogen as additive in liquid paraffin.