Ultrafine diamond (UFD) is produced at high pressure and high temperature generated by explosive detonation. We manage to search for a new technology to purify the UFD by using potassium permanganate and concentrated ...Ultrafine diamond (UFD) is produced at high pressure and high temperature generated by explosive detonation. We manage to search for a new technology to purify the UFD by using potassium permanganate and concentrated sulfuric acid as oxidant. The experiment results show that, compared with others, the purifying effect by this technology is satisfactory and is a more efficient, cheaper, and safer purification technology with less pollution and less investment. It can be put into commercial use. The related principle of the technology is discussed. It is believed that the atomic state oxygen produced during the reaction mechanism is an active substances which would react with the graphite——the main impurity existing in the detonation soot, and the reaction temperature is the key factor in the process.展开更多
Due to the excellent combination of wear resistance and fracture toughness,the ultrafine-grained WC-Co composites can significantly improve the durability and reliability of industrial tools.However,the grinding of ul...Due to the excellent combination of wear resistance and fracture toughness,the ultrafine-grained WC-Co composites can significantly improve the durability and reliability of industrial tools.However,the grinding of ultrafine-grained WC-Co remains a challenge.In order to provide an experimental basis for improving grinding quality of ultrafine-grained WC-Co,a series of surface grinding experiments on ultrafine-grained WC-Co hardmetals were conducted by diamond wheel under various grinding conditions,and the material removal behavior and surface integrity in grinding of ultrafine-grained WC-Co materials were characterized by means of scanning electron microscopy(SEM),X-ray microstress analyzer and surface roughness analyzer in this paper.The results indicate that the material removal behavior in grinding of ultrafine-grained WC-Co materials is determined not only by the abrasive grain size on the wheel,but also by the depth of cut.The roughness values of ground surface increase with increasing grit size of diamond wheel,and increase initially,then decrease with increase in depth of cut.Grinding causes the residual compressive stress in the surface layer of ground cemented carbides under various grinding conditions;the magnitude of residual surface stress increases with increasing grit size of diamond wheel,and isn't changed obviously along with the change of depth of cut.展开更多
文摘Ultrafine diamond (UFD) is produced at high pressure and high temperature generated by explosive detonation. We manage to search for a new technology to purify the UFD by using potassium permanganate and concentrated sulfuric acid as oxidant. The experiment results show that, compared with others, the purifying effect by this technology is satisfactory and is a more efficient, cheaper, and safer purification technology with less pollution and less investment. It can be put into commercial use. The related principle of the technology is discussed. It is believed that the atomic state oxygen produced during the reaction mechanism is an active substances which would react with the graphite——the main impurity existing in the detonation soot, and the reaction temperature is the key factor in the process.
基金National Science and Technology Major Project,China(No.2012ZX04003031)
文摘Due to the excellent combination of wear resistance and fracture toughness,the ultrafine-grained WC-Co composites can significantly improve the durability and reliability of industrial tools.However,the grinding of ultrafine-grained WC-Co remains a challenge.In order to provide an experimental basis for improving grinding quality of ultrafine-grained WC-Co,a series of surface grinding experiments on ultrafine-grained WC-Co hardmetals were conducted by diamond wheel under various grinding conditions,and the material removal behavior and surface integrity in grinding of ultrafine-grained WC-Co materials were characterized by means of scanning electron microscopy(SEM),X-ray microstress analyzer and surface roughness analyzer in this paper.The results indicate that the material removal behavior in grinding of ultrafine-grained WC-Co materials is determined not only by the abrasive grain size on the wheel,but also by the depth of cut.The roughness values of ground surface increase with increasing grit size of diamond wheel,and increase initially,then decrease with increase in depth of cut.Grinding causes the residual compressive stress in the surface layer of ground cemented carbides under various grinding conditions;the magnitude of residual surface stress increases with increasing grit size of diamond wheel,and isn't changed obviously along with the change of depth of cut.
