The Forming Process And Microstructure Control Of Nano-Diamond Ultrafine Grinding Tools

At present,most of the nano-diamond ultra-fine grinding tools are prepared by using traditional molding processes such as cold pressure,and can not make the diamond evenly dispersed in the abrasive,can not guarantee the consistency of the processing surface quality,and the nano-diamond ultra-fine grinding tool prepared by the traditional molding process has small porosity and uneven distribution,The grinding performance of nano-diamond ultra-fine grinding tool is reduced.Therefore,the nano-diamond ultra-fine grinding tools are prepared by direct foaming gel injection molding process,and the nano-diamond ultra-fine grinding tools with uniform structure,porosity greater than 80%and stable and dispersed diamond are prepared by adjusting the technological parameters.Ceramic Binder abrasives with ultra-high porosity were prepared by direct foaming gel injection molding process,and their microstructure was regulated.The samples of ceramic abrasives were characterized by field emission scanning electron microscope?FESEM?,Thermal Analyzer?DSC-TG?and X-ray Diffractometer?XRD?,and the viscosity,suspension stability,curing time and foaming amount of ceramic binder and SiC mixed slurry were tested,and the flexural strength of abrasive samples after sintering was shrinkage,porosity and volume density were tested.The results show that when the addition of ammonium citrate and ammonium polyacrylate is 1.8 wt.%and 2 wt.%,respectively,and when the pH value of the mixture slurry is around 10,the dispersion uniformity and suspension stability of the mixture slurry are the best;when the concentration of AM is around 8 wt.%,and the addition of APS and TEMED is within the range of 1.0¹.2 wt.%and 240³20?L,respectively,the curing time of the mixture slurry is the lowest.When the solid content of surfactant,the speed of mixer and the mixing time are controlled at about40 wt.%,2 g/L,1000 r/min and 15 min,respectively,the pore structure of ultra-high porosity ceramic abrasives is better;the optimum sintering temperature of abrasive samples is 550?.The samples of ultra-fine grinding tools were prepared by adding different concentrations of ND@SiO₂.The samples of ultra-fine grinding tools were characterized by FESEM,DSC-TG and XRD,and the flexural strength,shrinkage,porosity and volume density of the abrasive samples were tested after sintering.The experimental results show that,with the increase of ND@SiO₂ concentration from 25%to 100%,the ND@SiO₂ of different concentrations are evenly and stably dispersed in ultra-fine grinding tools,and the optimum sintering temperature of abrasive samples is increased from 550?to 575?,and the flexural strength is 46.52⁵3.65 MPa,shrinkage is 1.76².28%,porosity is 80.7⁸7.5%,volume density is 0.35⁰.41 g/cm³,and ultra-fine grinding tool samples of the tissue structure and stomatal distribution is more uniform.