Nanoparticles are increasingly being used to improve the friction and wear performance of polymers. In this study, we investigated the tribological behavior and energy dissipation characteristics of nano-Al_2O_3-reinf...Nanoparticles are increasingly being used to improve the friction and wear performance of polymers. In this study, we investigated the tribological behavior and energy dissipation characteristics of nano-Al_2O_3-reinforced polytetrafluoroethylenepolyphenylene sulfide(PTFE-PPS) composites in a sliding system. The tribological behaviors of the composites were evaluated under different normal loads(100–300 N) at a high linear velocity(2 m/s) using a block-on-ring tester. Addition of the nano-Al_2O_3 filler improved the antiwear performance of the PTFE-PPS composites, and the friction coefficient increased slightly. The lowest wear rate was obtained when the nano-Al_2O_3 content was 3%(volume fraction). Further, the results indicated a linear correlation between wear and the amount of energy dissipated, even though the wear mechanism changed with the nano-Al_2O_3 content, independent of the normal load applied.展开更多
SiO2-Al2O3/EP-PU nanocomposites, which contained polyurethane(PU) flexible chain, were prepared via epoxy resin, PU and modified silica and alumina particles. Silica and alumina particles were modified by coupling age...SiO2-Al2O3/EP-PU nanocomposites, which contained polyurethane(PU) flexible chain, were prepared via epoxy resin, PU and modified silica and alumina particles. Silica and alumina particles were modified by coupling agents KH-560 and KH550, respectively. EP-PU was used as matrix, PU as toughening agent, Si O2-Al2O3 as filled and MTHPA as curing agent. The mass ratio of PU was 30% in this system. The chemical structure of the products was confirmed by FT-IR measurements, the morphological structure of fracture surface and the surface of the hybrid materials were observed by scanning electron microscope(SEM) and transmission electron microscope(TEM), and shearing strength and breakdown field were measured, respectively. When the mass fraction of inorganic component was 10% and the mass ratio of Si O2 to Al2O3 was 4.5:5.5, shearing strength of Si O2-Al2O3/EP-PU was 28.5 MPa and breakdown field was 15 k V/mm, the data could meet the property requirement of insulating material.展开更多
Ni-Co-Fe2O3 composite coatings were electrodeposited using cetyltrimethylammonium bromide(CTAB)-modified Watt's nickel bath with Fe2O3 particles dispersed in it.The effects of the plating parameters on the chemica...Ni-Co-Fe2O3 composite coatings were electrodeposited using cetyltrimethylammonium bromide(CTAB)-modified Watt's nickel bath with Fe2O3 particles dispersed in it.The effects of the plating parameters on the chemical composition,structural and morphological characteristics of the electrodeposited Ni-Co-Fe2O3 composite coatings were investigated by energy dispersive X-ray(EDS) spectroscopy,X-ray diffractometry(XRD) and scanning electron microscopy(SEM).The results reveal that Fe2O3 particles can be codeposited in the Ni-Co matrix.The codeposition of Fe2O3 particles with Ni-Co is favoured at high Fe2O3 particle concentration and medium stirring,and the deposition of Co is favoured at high concentration of CTAB.Moreover,the study of the textural perfection of the deposits reveals that the presence of particles leads to the worsening of the quality of the observed <220> preferred orientation.Composites with high concentration of embedded particles exhibit a preferred crystal orientation of <111>.The more the embedded Fe2O3 particles in the metallic matrix,the smaller the sizes of the crystallite for the composite deposits.展开更多
基金Project(51165022)supported by the National Natural Science Foundation of ChinaProject(20122117)supported by the Lanzhou Science and Technology Bureau Foundation,ChinaProject(1310RJZA036)supported by the Natural Science Foundation of Gansu Province,China
文摘Nanoparticles are increasingly being used to improve the friction and wear performance of polymers. In this study, we investigated the tribological behavior and energy dissipation characteristics of nano-Al_2O_3-reinforced polytetrafluoroethylenepolyphenylene sulfide(PTFE-PPS) composites in a sliding system. The tribological behaviors of the composites were evaluated under different normal loads(100–300 N) at a high linear velocity(2 m/s) using a block-on-ring tester. Addition of the nano-Al_2O_3 filler improved the antiwear performance of the PTFE-PPS composites, and the friction coefficient increased slightly. The lowest wear rate was obtained when the nano-Al_2O_3 content was 3%(volume fraction). Further, the results indicated a linear correlation between wear and the amount of energy dissipated, even though the wear mechanism changed with the nano-Al_2O_3 content, independent of the normal load applied.
基金Project(2012RFJGG006)supported by the Harbin Science and Technology Innovation Foundation,China
文摘SiO2-Al2O3/EP-PU nanocomposites, which contained polyurethane(PU) flexible chain, were prepared via epoxy resin, PU and modified silica and alumina particles. Silica and alumina particles were modified by coupling agents KH-560 and KH550, respectively. EP-PU was used as matrix, PU as toughening agent, Si O2-Al2O3 as filled and MTHPA as curing agent. The mass ratio of PU was 30% in this system. The chemical structure of the products was confirmed by FT-IR measurements, the morphological structure of fracture surface and the surface of the hybrid materials were observed by scanning electron microscope(SEM) and transmission electron microscope(TEM), and shearing strength and breakdown field were measured, respectively. When the mass fraction of inorganic component was 10% and the mass ratio of Si O2 to Al2O3 was 4.5:5.5, shearing strength of Si O2-Al2O3/EP-PU was 28.5 MPa and breakdown field was 15 k V/mm, the data could meet the property requirement of insulating material.
基金Project(2005CB623703) supported by the National Key Basic Research Program of ChinaProject(50474051) supported by the National Natural Science Foundation of China+2 种基金Project(CX2009B032) supported by Innovation Foundation for Postgraduate of Hunan Province of China Project(ZKJ2009024) supported by the Precious Apparatus Open Share Foundation of Central South University, ChinaProject(2009ybfz02) supported by Excellent Doctor Support Fund of Central South University,China
文摘Ni-Co-Fe2O3 composite coatings were electrodeposited using cetyltrimethylammonium bromide(CTAB)-modified Watt's nickel bath with Fe2O3 particles dispersed in it.The effects of the plating parameters on the chemical composition,structural and morphological characteristics of the electrodeposited Ni-Co-Fe2O3 composite coatings were investigated by energy dispersive X-ray(EDS) spectroscopy,X-ray diffractometry(XRD) and scanning electron microscopy(SEM).The results reveal that Fe2O3 particles can be codeposited in the Ni-Co matrix.The codeposition of Fe2O3 particles with Ni-Co is favoured at high Fe2O3 particle concentration and medium stirring,and the deposition of Co is favoured at high concentration of CTAB.Moreover,the study of the textural perfection of the deposits reveals that the presence of particles leads to the worsening of the quality of the observed <220> preferred orientation.Composites with high concentration of embedded particles exhibit a preferred crystal orientation of <111>.The more the embedded Fe2O3 particles in the metallic matrix,the smaller the sizes of the crystallite for the composite deposits.
