Physicochemical and Tribological Properties of Anti-Seize Thread Lubricant

The di-aromatics base oil and graphite powder,blended with the viscosity index improver,and the anti-oxidant and rheological additive,were used to prepare a kind of anti-seize thread lubricant.Its physical chemistry properties,such as water resistance,thermal oxidation and aging properties,and tribological performance,were evaluated and compared with those of some commercial products.The results show that the overall performance of the anti-seize thread lubricant could meet the level of some commercial products,while its some properties such as thermal stability,anti-wear and anti-friction properties were better.The said anti-seize thread lubricant is more suitable for use under high temperature conditions.

Restoration of enamel anti-wear properties via remineralization: Role of occlusal loading

In this in vitro study,the restoration of acid-eroded enamel surface morphology and anti-wear properties under two conditions,mono-remineralization(treated with remineralization alone)and impact-remineralization(treated with cyclic impact followed by remineralization),are characterized to determine the effect of occlusal loading on enamel remineralization.Compared with the mono-remineralized surface,the impact-remineralized surface demonstrates better anti-wear performance,as manifested by a higher hardness and elastic modulus,as well as a lower friction coefficient and wear volume.Loading on the eroded enamel surface induces the fragmentation of hydroxyapatite nanoparticles,which aids crystal deposition and fusion during subsequent remineralization.In summary,owing to the enamel microstructure,occlusal loading can promote the restoration of enamel anti-wear properties by enhancing remineralization.Remineralization enhancement through occlusalloading-induced nanoparticle fragmentation plays a significant role in preventing human teeth from excessive wear.

Lubricating Performance of Rapeseed Oil Under Electromagnetic Field

Considering electromagnetic effect when investigating tribological properties of rapeseed oil is benefical not only to the improvement of green lubrication, but also to the development of tribology theories and practices. In the present paper, the tribological properties of rapeseed oil under different intensity of electromagnetic field and normal loads were evaluated on a modified tribo-tester. The results indicated that the electromagnetic field could improve the anti-wear and friction-reducing property of the rapeseed oil. Furthermore, the influencing mechanisms were discussed from the perspective of electromagnetism according to the analytical results of SEM, EDS and XPS techniques.

Experimental Study on Friction Reducing and Anti Wear Property of a Water-Based Lubricant with Polyether Added

The wear behaviors of steel-steel pair on condition of a water-based lubricant with copolymer of acylamino polyoxyethylene polyoxypropylene ether(KE-1)included as additives are investigated with the help of the universal micro-tribotester.Tests on friction and wear are carried out.As a reference,some tests with pure water are also performed for comparison.The results show that the prepared water-based lubricant has a good effect on the characteristics associated with friction reducing and anti-wear processes,which lay some credence to its utilization in practical industrial tribo-systems.

Oil-soluble polymer brushes-functionalized nanoMOFs for highly efficient friction and wear reduction

Nanomaterials as lubricating oil additives have attracted significant attention because of their designable composition and structure,suitable mechanical property,and tunable surface functionalities.However,the poor compatibility between nanomaterials and base oil limits their further applications.In this work,we demonstrated oil-soluble poly(lauryl methacrylate)(PLMA)brushes-grafted metal-organic frameworks nanoparticles(nanoMOFs)as lubricating oil additives that can achieve efficient friction reduction and anti-wear performance.Macroinitiators were synthesized by free-radical polymerization,which was coordinatively grafted onto the surface of the UiO-67 nanoparticles.Then,PLMA brushes were grown on the macroinitiator-modified UiO-67 by surface-initiated atom transfer radical polymerization,which greatly improved the lipophilic property of the UiO-67 nanoparticles and significantly enhanced the colloidal stability and long-term dispersity in both non-polar solvent and base oil.By adding UiO-67@PLMA nanoparticles into the 500 SN base oil,coefficient of friction and wear volume reductions of 45.3%and 75.5%were achieved due to their excellent mechanical properties and oil dispersibility.Moreover,the load-carrying capacity of 500 SN was greatly increased from 100 to 500 N by the UiO-67@PLMA additives,and their excellent tribological performance was demonstrated even at a high friction frequency of 65 Hz and high temperature of 120℃.Our work highlights oil-soluble polymer brushes-functionalized nanoMOFs for highly efficient lubricating additives.