Preparation and Composition Distribution in Hollow Tubular TiB-Ti Composites during Centrifugal Spraying Process

【摘要】 The hollow cylinders of TiB-Ti composites with a gradient distribution of Ti phase were synthesized by the combination of traditional slurry spray with centrifugal forming process.The influences of the concentration of sodium hexametaphosphate （SHMP）,the concentration of polyvinyl alcohol （PVA） and solid content （20 vol%-35 vol%） on the rheological properties of the TiB₂-Ti composite slurries were investigated.Slurries with low viscosity,weak thixotropy and shear-thinning behaviour were obtained for facilitating the slurry spraying process.The effects of different centrifugal conditions on the migration of components during the forming process were studied.The phase composition and the elements distribution of the prepared samples were characterized by the energy-dispersive X-ray spectrometer.The observations revealed that the samples fabricated at 1 500 r/min for 3 min had a significant composition variation.For two-phase systems with small density differences and large particle size variation,centrifugal time was more important than centrifugal speed in forming a continuous gradient structure.更多还原

【Abstract】 The hollow cylinders of TiB-Ti composites with a gradient distribution of Ti phase were synthesized by the combination of traditional slurry spray with centrifugal forming process.The influences of the concentration of sodium hexametaphosphate （SHMP）,the concentration of polyvinyl alcohol （PVA） and solid content （20 vol%-35 vol%） on the rheological properties of the TiB₂-Ti composite slurries were investigated.Slurries with low viscosity,weak thixotropy and shear-thinning behaviour were obtained for facilitating the slurry spraying process.The effects of different centrifugal conditions on the migration of components during the forming process were studied.The phase composition and the elements distribution of the prepared samples were characterized by the energy-dispersive X-ray spectrometer.The observations revealed that the samples fabricated at 1 500 r/min for 3 min had a significant composition variation.For two-phase systems with small density differences and large particle size variation,centrifugal time was more important than centrifugal speed in forming a continuous gradient structure.更多还原