Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifie...Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.展开更多
Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding ...Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.展开更多
The one-dimensional carbon nanotubes/nanorods(CNT/CNR)mixed nano-carbon material was successfully prepared by halloysite nanotubes(HNTs)as the template for the first time,in which CNT was formed through PVA modificati...The one-dimensional carbon nanotubes/nanorods(CNT/CNR)mixed nano-carbon material was successfully prepared by halloysite nanotubes(HNTs)as the template for the first time,in which CNT was formed through PVA modification in internal surface of HNTs and CNR was obtained by nanocasting PVA in hollow nanostructure of HNTs.The CNT of the mixture with flexible structure has ca.20 nm in pore diameter and ca.500 nm in length,whereas the CNR with hard and solid structure shows ca.30 nm in diameter and ca.2μm in length.For application as fillers,the CNT/CNR mixed nano-material is used to reinforce the properties of polytetrafluoroethylene(PTFE).The mechanical and tribological properties of PTFE nanocomposites were intensively examined by a series of testing.The ring-on-ring counterface was used to evaluate the tribological behavior of the nanocomposites.The results showed that the volume wear rate of the CNT/CNR-reinforced PTFE nanocomposite after being filled with 0.3%of CNT/CNR was only 1/700 of that of the pure PTFE under a load of 200 N and a rotary speed of 200 r/min,while other mechanical and tribological performance was comparable to the performance of pure PTFE,which exhibited a desirable application prospect.展开更多
The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the po...The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the polymer-based composite.Unfortunately,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite scarce.Therefore,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear tester.The scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the counterparts.The tensile properties of the composites are evaluated on the universal material testing machine.The test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania particles.The proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51165022,51675509)
文摘Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.
基金Supported by the National Natural Science Foundation of China(No.51165022)Lanzhou Science and Technology Bureau Foundation(No.20122117)the Natural Science Foundation of Gansu Province(No.1310RJZA036).
文摘Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.
基金funded by the Talent Introduction Fund of Yangzhou University(2012)the Zhenjiang High Technology Research Institute of Yangzhou University(2017)+5 种基金the Key Research Project-Industry Foresight and General Key Technology of Yangzhou(YZ2015020)the Innovative Talent Program of Green Yang Golden Phoenix(yzlyjfjh2015CX073)the Yangzhou Social Development Project(YZ2016072)the Jiangsu Province Six Talent Peaks Project(2014-XCL-013)the Jiangsu Industrial-Academic-Research Prospective Joint Project(BY2016069-02)the Priority Academic Program Development of Jiangsu Higher Education Institutions and Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(PPZY2015B112)for the financial support
文摘The one-dimensional carbon nanotubes/nanorods(CNT/CNR)mixed nano-carbon material was successfully prepared by halloysite nanotubes(HNTs)as the template for the first time,in which CNT was formed through PVA modification in internal surface of HNTs and CNR was obtained by nanocasting PVA in hollow nanostructure of HNTs.The CNT of the mixture with flexible structure has ca.20 nm in pore diameter and ca.500 nm in length,whereas the CNR with hard and solid structure shows ca.30 nm in diameter and ca.2μm in length.For application as fillers,the CNT/CNR mixed nano-material is used to reinforce the properties of polytetrafluoroethylene(PTFE).The mechanical and tribological properties of PTFE nanocomposites were intensively examined by a series of testing.The ring-on-ring counterface was used to evaluate the tribological behavior of the nanocomposites.The results showed that the volume wear rate of the CNT/CNR-reinforced PTFE nanocomposite after being filled with 0.3%of CNT/CNR was only 1/700 of that of the pure PTFE under a load of 200 N and a rotary speed of 200 r/min,while other mechanical and tribological performance was comparable to the performance of pure PTFE,which exhibited a desirable application prospect.
文摘The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the polymer-based composite.Unfortunately,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite scarce.Therefore,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear tester.The scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the counterparts.The tensile properties of the composites are evaluated on the universal material testing machine.The test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania particles.The proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.
