Papers by Author: Yuan Kang Zhou

Abstract: The orthogonal experimental study is carried out to study the Incorporation of different proportion of functional components and the effect on tribological performance among semi-metallic friction materials. A test is conducted for each sample on XXD-MSM constant speed tester in accordance with Brake Linings for Automobiles (GB5763-2008). The friction factor and high-temperature abrasion resistance properties are evaluated along with the obtaining of optimal formula, and the mechanism of affecting the tribological properties is analyzed on the worn surfaces by using a scanning electron microscope (SEM). The study results indicate that the high-temperature friction stability could be deeply affected by the adequate content of steel fiber, Kevlar pulp, potassium hexatitanate whisker and cashew nut shell. The mechanism of High-temperature tribological behaviors are the thermal decompositions. The thermal decomposition of organic matter might greatly weakened the bonding effect. The thermal decomposition of tribo-film fall off as lamellar chip under the effect of friction stress. The addition level of nanoparticles is 3%, the sample’s tensile strength, tensile strength, hardness index and noise level are better. If the modified resin is further applied, this formula can be close to the index of excellent Chinese industrial product JF04-20.

Abstract: The silane coupling agent KH550 is used to modify foamed Fe powder(FFP) surface for obtain the hydrophobic surface, which is the very important component in semi-metallic friction material. It can improve high temperature bonding force between FFP and phenolic resin, further improve friction coefficient stableness of friction material and abrasion resistance. The modification effect of FFP is characterized by IR, and the tribological properties is characterized by XD-MSM constant speed friction test machine, the surface topography is characterized by SEM. The results indicate that FFP has been bonded to silane coupling agent, and formed hydrophobic surface what has the alkyl group. The changing of friction coefficient has reduced 23%, the average wear rate has declined 28.6%,and the wear rate has declined 32% at 350 °C after the friction material with modified FFP compare with the one with original FFP. And those changing are all because of the fact that the FFP modified by KH550 is difficult to peel off during the high temperature.

Abstract: A type of phenolic resin (PF) was prepared by using TiO₂ nanoparticles modified with KH-550 as composite filler and modifier, and then the composite modified PF were used as adhesive to prepare semi-metallic friction materials samples. TG analysis of the prepared nano-TiO₂ /PF composites was conducted on SETARAM-TG2DSC92216 thermal analyzer that was made in France, and the friction and wear property comparison tests of the samples were carried out on XD-MSM fixed speed friction-wear machine. The results show that the heat resistance of phenolic resin after being compositely modified by TiO₂ nanoparticles can be improved, carbon residue rate increases10% at 600°C；the friction coefficient of the corresponding sample slightly increases；the wear rate clearly decreases at high temperature, and wear rate decreases 10% at 350°C.

Abstract: In this paper, some Ag-carried palygorskite nanocomposites P/Ag were prepared, their silver content were 1.3%, 4.61%, 9.54% separately. To investigate the effects of the silver content on tribological properties of 45 mild steel pairs, the P/Ag carried different Ag content were used as lubricant additive and their tribological properties were tested on the MMU-10G testing machine. The wear mass loss is used to assess the anti-wear properties of different additives. The surface topographies and main elements are analyzed through SEM and EDS after running for 30 hours. The results show that the friction coefficient and the wear mass loss significantly decrease along with the increase of silver content in the P/Ag: the average friction coefficient of the P/Ag with 9.54% silver reduces about 65% as much as the one with 1.3% silver, meanwhile, the wear mass loss decreases 57% likewise. The surfaces after rubbing 30 hours, some kind of auto-restoration films that contains sort of characteristic elements such as O, Si, Mg, Al, Ag etc. are formed on the surfaces. With the help of this kind of films, the anti-wear properties of the friction pairs are finally improved. The factors that cause the improvement of anti-friction properties of the friction pairs lie in the quality and the silver content of the auto-restoration films formed on the surfaces of friction pairs.

Abstract: Palygorskite/copper nanocomposites were prepared in order to study the friction behaviour and self-repairing effect of HT200 tribopair. The friction and wear behaviors of the lubricant oil containing 4wt% nanocomposites were evaluated on an MMU-10G abrasive-wear tester. Results indicated that the average size of nanoparticles is 200nm and nanoparticle disperses homogeneously. The nanocomposites significantly improve the anti-wear performance.Wear mass loss decreases 41.7%and 63.2% compared with nano-palygoeskite and no additive.SEM and EDX examination of worn surfaces show that the incorporation of nano-copper and nano-palygorskite promote the formation of enriched films which play beneficial role for improving the wear properties.