The main developments and research of polycrystalline cubic boron nitride(PCBN)products are reviewed based on categories,binders,microstructure homogeneity and impact toughness.Moreover,new materials such as nanopolyc...The main developments and research of polycrystalline cubic boron nitride(PCBN)products are reviewed based on categories,binders,microstructure homogeneity and impact toughness.Moreover,new materials such as nanopolycrystalline CBN and non-binder PCBN are introduced,including characteristics and future applications.展开更多
Basing on the commercial CFD metho d ,several models are adopted to simulate water model. The numerical simulation results are in good agreement with the experimental data of water model under the same experimental co...Basing on the commercial CFD metho d ,several models are adopted to simulate water model. The numerical simulation results are in good agreement with the experimental data of water model under the same experimental conditions. Then the numerical simulation method is presented to investigate the flow field, the vortex on gas-liquid surface and the uniform mixing time in hot metal ladles. This research shows: the vortex depth increases with increasing of immersion depth and rotation speed; Overflow appears in N=120rpm and h=3.2m; the turbulent kinetic energy increases with increasing immersion depth and rotation speed; uniform mixing time decreases with the decreasing of immersion depth and the rotation speed of stirring ; the optimal uniform mixing time is 23.5s on the conditions of N=100rpm and h=3.2m within the allowable range.展开更多
文摘The main developments and research of polycrystalline cubic boron nitride(PCBN)products are reviewed based on categories,binders,microstructure homogeneity and impact toughness.Moreover,new materials such as nanopolycrystalline CBN and non-binder PCBN are introduced,including characteristics and future applications.
基金supported by the National Natural Science Foundation of China(No.50974035)National Natural Science Foundation of China(No.51074047)the Doctoral Fund of EDU Gov(20090407)
文摘Basing on the commercial CFD metho d ,several models are adopted to simulate water model. The numerical simulation results are in good agreement with the experimental data of water model under the same experimental conditions. Then the numerical simulation method is presented to investigate the flow field, the vortex on gas-liquid surface and the uniform mixing time in hot metal ladles. This research shows: the vortex depth increases with increasing of immersion depth and rotation speed; Overflow appears in N=120rpm and h=3.2m; the turbulent kinetic energy increases with increasing immersion depth and rotation speed; uniform mixing time decreases with the decreasing of immersion depth and the rotation speed of stirring ; the optimal uniform mixing time is 23.5s on the conditions of N=100rpm and h=3.2m within the allowable range.
