Tao De-hua

Research on Friction-Coatings with Activated Ultra-Thick Tin-Base

This paper introduced a new Nanometer-Tin lubricating additive. Through the friction testing on an improved testing machine, the Nanometer additive with different contents used in Steel-Copper Tribo-pair has been investigated by analyzing the surface elements with AES and measuring the thickness and element distribution of the coating with SEM. The result shows that the weight of copper sample has obviously increased, and the ultra-thick friction coating (10μm−20μm), has formed on the surface of the copper sample. The experiment proved that the high concentrated Sn coating has good frictional properties. Therefore, the researching results possess significance to self-repair in wearing for mechanical system.

Rheological and tribological characteristics of the synthesized lubricants derived from vegetable oils

The double bonds in the vegetable oils can be conjungated and Diels-Alder react when they are heated in the existence of the catalyst. The percent of the double bond will decrease and the oxidative stability of the vegetable oils can be ameliorated. Dimmer acid can react with different carbon chain length of alcohols to form dimmer acid esters. A series of dimmer acid esters were synthesized and their rheological characteristics (viscosity, viscosity index, pour point) and tribological characteristics (the coefficient of friction at different load, the characteristic of extreme pressure (PB), the wear scare diameter (D30 min196 N) were evaluated and analyzed. The results showed that the characteristics of Di-iso-octanol dimmer acid ester were the best among the synthesized dimmer esters. It’s a lubricant with good properties (the viscosity is 94.5 mm2/s, the viscosity index is high up to 141 and the pour point is −49t). It is a kind of newly interesting ester type lubricant. Its rheological and tribological characteristics are even better than those of the slap-up synthesized lubricant-pentaerythritol esters (C7–9 acidate). The FT-IR spectrophotometer was used to analyze the structure of the synthetic esters. Their IR spectra are the same as the typical IR spectrum of ester. The test indicated that Di-iso-octanol dimmer acid ester could be used as a kind of base lubricant with excellent quantity.

Preparation and tribological performance of novel organotin compound as lubricant additive

Oil-soluble stannous naphthenate (SN) is synthesized by using naphthenatic acid and SnO. And its molecular structure is confirmed by IR and multielement oil analyzer (MOA). The tribological performances of the organotin as lubricant additive are evaluated with a four-ball friction and wear tester. These experiments indicate that the wear scar diameter (WSD) and friction coefficient are diminished while the load-carrying capability increased by comparison with that of base oil. The elemental composition of the boundary lubricating film is examined by means of Auger electron spectroscopy (AES). Synergistic effect is found in the load-carrying capability of the complex of SN and sulfured olefin. The analytical results of AES indicate that the good performance of stannous naphthenate is attributed to the formation of a boundary lubricating film containing Sn on the rubbed surface.