Research On Preparation And Properties Of Cermets Bonded Diamond Grinding Tool

The properties of vitrified bond diamond grinding tools and metal bond diamondgrinding tools have both desirable sides and deficient sides. Contraposing thedisadvantages, it is necessary to study a new kind of bond with the merits of both thevitrified bond and metal bond. In this work, iron group metallic elements （Ni, Co, Fe）were introduced to vitrified bond based on R₂O-B₂O₃-Al₂O₃-SiO₂. Through themethods of refractory cone, plane flow, three-point bending tester, Rockwell hardnesstest, DSC-TG, X-diffraction analysis, scan-electrcscope and energy spectrum analysis,the properties of vitrified bond and grinding tool was discussed. The grindingperformances of ceramets bond diamond wheels were tested in the grindingexperiments.The results showed that the addition of iron group metallic elements had certaineffects on the properties of vitrified bond. The refractoriness of the vitrified bondincreased with the introduction of Co, but decreased apparently with the addition ofless than20%Fe, while Ni had little influence on the refractoriness. When sintered at750℃, the interface between Ni, Co and vitrified bond was altered into chemical bondby means of NiO, CoO, which made the combination closer. But apparent crackappeared between Fe and vitrified bond. Furthermore, the bending strength of vitrifiedbond increased differently by adding metal powders. When the mass fraction of Cowas25wt%, the bending strength of vitrified bond reached the maximum value of75.42MPa. Compared with52.59MPa of the basic vitrified bond, it was increased by43.39%.The bending strength and hardness of vitrified bond diamond grinding toolsincreased with different degree by adding Iron group metals （Ni, Co, Fe）. With15wt%Ni,10wt%Co and5wt%Fe, the strength, hardness and microstructure ofgrinding tools sintered at properly chosen temperature were improved greatly.Moreover, the sintering temperature had a certain extent effect on the properties ofgrinding tools. And the suitable sintering temperature of the vitrified bond diamond grinding tools with15wt%Ni,10wt%Co and5wt%Fe were780℃,810℃and780℃respectively.Diamond grinding wheels were fabricated using vitrified bond with10wt%Co.When they were used to cylindrical grinding polycrystalline diamond compacts, theworking life was nearly2-3times as long as resin bond wheels and was improved byabout10%compared to the market vitrified bond diamond wheels. And the higherefficiency and better surface quality could also be acquired...