| Vitrified/diamond composites possess fabulous characteristics such as high strength along with various processing range,which makes diamond composites widely used in High-efficiency grinding field.In this paper,the sintering system of vitrified bond diamond composites was explored;effects of pore formers on the structural properties of diamond composites were studied;effects of ZnS and ZnF2 on the properties of diamond composites were compared.The main research work and achievements are as follows:1.The influence of sintering temperature and thermal holding time was discussed.When the sintering temperature was 840℃and the holding time was 120 min,the bending strength of the diamond composites was 58.32 MPa and the porosity was20.77%.The vitrified bond distributed around diamond particles evenly,and plenty of bond"bridges"were generated between the diamonds.The sample has good sharpness.2.The effects of PMMA,Al2O3 sphere and ammonium sulfate on the structural properties of diamond composites were compared.Results showed that the PMMA can improve the structural properties of diamond composites greatly than other two pore formers.The PMMA with average particle size of 45μm and 3 wt.%additive could increase the diamond composites porosity to 26.85%,which was 6%higher than that without adding;the bending strength was 51.78 MPa.3.The effects of ZnS and ZnF2 on the properties of diamond composites were studied.The results showed that the effects of ZnS on diamond composite is stronger than that of ZnF2.The bending strength of 6 wt.%ZnS diamond composites was 76.52MPa,and the CTE was 3.44×10-6℃-1.β-spodumene crystals distributed around the diamond particles uniformly.The introduction of F-can reduce the viscosity of vitrified bond,the bending strength of diamond composites added with 4 wt.%ZnF2 is 72.47MPa,the density is 2.43 g/cm3,and the diamond was coated by the vitrified bond.However,excessive ZnF2 damages the properties of diamond materials sharply. |
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