Study On The Synthesis And Tribology Propepties Of MSe₂ (M=Mo, Ti) Nanomaterials

Transitional metal dichalcogenides MX₂(M=W, Mo, Nb, Ta; X=S, Se)have lamellar close-packed hexagonal structures, which was used as solid lubricants extensively. The dangling bonds on the edge of crystal have chemical activity, and are easily oxidized in ambient conditions, the friction properties of lubricants decrease obviously. The unique closed one dimensional nanostructure (nanotubes, nanowires, nanobundles) formed with rolled up MS₂ (M=W, Mo, Nb, Ta) materials have eliminated the fringe dangling bonds, which improve the chemical stability and have very expansive application prospects on tribology aspects. In recent years , investigations on these mamaterials developed quckly, especially on selenides. Also, with in-deepth study, Selenium compounds composites are found to have better tribological properties, in addition, nanomaterials of Selenium compounds have important applications on superconducting, photocatalysis aspects and so on which make these materials much more extensive applications. Besides, many sulphides can be obtained from natural minerals, but selenides can only be synthesized, so the investigations on synthesis and tribological properties of these selennides gradually grow to be more and more important. Therefore, it will be great significance to strengthen the research on selenides nanostructures.In this article, experimental investigation and theoretical analysis were carried out on the preparation process and tribology properties of dimensional MSe₂ (M= Mo, Ti) nanostructures.Firstly, the solid-phase reaction was used to produce MoSe₂/C nanoflakes in a stainless steel reactor or in a porcelain with another one over it under argongas atomosphere by mixed Se and Mo(CO)6 powder at elevated temperature. The as-obtained products were investigated by means of several measurements.Secondly, MoSe₂ nanoflakes were obtained by heating stainless steel reactors containing mixture of Se and Mo powders inside a cannular furnace. The as-obtained products were investigated by means of several measurements.Thirdly, the mixture of Se and Ti powders were milling in high energy ball-milling machine, the mixture after milling were pressed to cylindrical pellets and heated in tubular furnace under argongas atomosphere, then the products of TiSe₂ particals were obtained. The as-obtained TiSe₂ powders were mixed with powders Fe by several weight percentage and pressed to cylindrical pellets and heated in tubular furnace under argongas atomosphere again, finally the a seial of Fe-based Selenides composites were obtained. TiSe₂ and Fe-based Selenides composites were by means of several measurements.Fourthly, the tribological properties of MoSe₂/C andas additives in 150bn base oil were investigated by UMT-2 multispecimen tributester under determinate conditions. Researches have done to test the influence of load and rotating speed have on the friction coefficient and comparisons were made between these additives. Besides, the tribological properties of Fe-based Selenides composites were also investigated.At last, the friction mechanism of lubrication including MSe₂ as additives was discussed preliminary. The lubrication has excellent tribological proerties in high load may be due to the following factors: nanomaterial has unique closed structures, lubrication films and fill up-repair mechanisms.