The tribologieal performances between Si3N4 ceramic balls and GCr15 steel disks without lubrication both in air and in vacuum （6 × 10^-3Pa） are investigated. The results show that the friction coefficient and w...The tribologieal performances between Si3N4 ceramic balls and GCr15 steel disks without lubrication both in air and in vacuum （6 × 10^-3Pa） are investigated. The results show that the friction coefficient and wear in vacuum are smaller than those in air. The friction mainly occurs between steel and steel in air because the steel is obvious to adhere on the ceramic surface. The ceramic and steel are hard to adhere in vacuum. The function of mechanical plough and the rotation of small wear particles in the contact region reduce the friction and wear between the ceramic and steel in vacuum.展开更多
Micrometer and nanometer Cr particles were co-deposited with Ni by electroplating from a nickel sulfate bath containing a certain content of Cr particles. Cr microparticles are in a size range of 1-5 μm and Cr nanopa...Micrometer and nanometer Cr particles were co-deposited with Ni by electroplating from a nickel sulfate bath containing a certain content of Cr particles. Cr microparticles are in a size range of 1-5 μm and Cr nanoparticles have an average size of 40 nm. The friction and the wear performance of the co-deposited Ni-Cr composite coatings were comparatively evaluated by sliding against Si3N4 ceramic balls under non-lubricated conditions. It is found that the incorporation of Cr particles enhances the microhardness and wear resistance of Ni coatings. The wear resistance of Ni composite coating containing Cr nanoparticles is higher than that of the Ni composite coating containing Cr microparticles with a comparable Cr particle content. The co-deposition of smaller nanometer Cr particles with Ni effectively reduces the size of Ni crystals and significantly increases the hardness of the composite coatings due to grain-refinement strengthening and dispersion-strengthening,resulting in a significant improvement of wear resistance of the Ni-Cr nanocomposite coatings.展开更多
文摘The tribologieal performances between Si3N4 ceramic balls and GCr15 steel disks without lubrication both in air and in vacuum （6 × 10^-3Pa） are investigated. The results show that the friction coefficient and wear in vacuum are smaller than those in air. The friction mainly occurs between steel and steel in air because the steel is obvious to adhere on the ceramic surface. The ceramic and steel are hard to adhere in vacuum. The function of mechanical plough and the rotation of small wear particles in the contact region reduce the friction and wear between the ceramic and steel in vacuum.
基金Project(9951Z012) supported by the Major Programs of the Heilongjiang Provincial Education Department, ChinaProject(11531319) supported by the Scientific Research Fund of Heilongjiang Provincial Education Department, ChinaProject(06-13) supported by the Scientific Research Startup Foundation of Heilongjiang Institute of Science and Technology, China
文摘Micrometer and nanometer Cr particles were co-deposited with Ni by electroplating from a nickel sulfate bath containing a certain content of Cr particles. Cr microparticles are in a size range of 1-5 μm and Cr nanoparticles have an average size of 40 nm. The friction and the wear performance of the co-deposited Ni-Cr composite coatings were comparatively evaluated by sliding against Si3N4 ceramic balls under non-lubricated conditions. It is found that the incorporation of Cr particles enhances the microhardness and wear resistance of Ni coatings. The wear resistance of Ni composite coating containing Cr nanoparticles is higher than that of the Ni composite coating containing Cr microparticles with a comparable Cr particle content. The co-deposition of smaller nanometer Cr particles with Ni effectively reduces the size of Ni crystals and significantly increases the hardness of the composite coatings due to grain-refinement strengthening and dispersion-strengthening,resulting in a significant improvement of wear resistance of the Ni-Cr nanocomposite coatings.
