In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting ...In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.展开更多
Multistage fluidized beds are frequently used for product drying in industry. One advantage of these fluidized beds is that they can achieve a high throughput, when operated continuously. In this study, γ- A1203 part...Multistage fluidized beds are frequently used for product drying in industry. One advantage of these fluidized beds is that they can achieve a high throughput, when operated continuously. In this study, γ- A1203 particles were dried in a pilot-scale horizontal fluidized bed, without considering any comminution effects. For each experiment, the particle moisture content distribution and residence time distribution were determined. To take into account particle back mixing in our experiments, a one-dimensional pop- ulation balance model that considers particle residence time was introduced into a fluidized bed-drying model. Experimental particle residence time distributions were reproduced using a tank-in-series model. Subsequently, the moisture content distribution was implemented, as a second dimension to the popu- lation balance in this model. These two-dimensional simulations were able to describe the experimental data, especially the spread in the residual particle moisture distribution, much more accurately than one-dimensional simulations. Using this novel two-dimensional model, the effects of different operating parameters （process gas temperature, solid feed rate, superficial air velocity） on the particle moisture content distribution were systematically studied.展开更多
基金Suported by Advanced Technolgy center prject(No.10020604)
文摘In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.
文摘Multistage fluidized beds are frequently used for product drying in industry. One advantage of these fluidized beds is that they can achieve a high throughput, when operated continuously. In this study, γ- A1203 particles were dried in a pilot-scale horizontal fluidized bed, without considering any comminution effects. For each experiment, the particle moisture content distribution and residence time distribution were determined. To take into account particle back mixing in our experiments, a one-dimensional pop- ulation balance model that considers particle residence time was introduced into a fluidized bed-drying model. Experimental particle residence time distributions were reproduced using a tank-in-series model. Subsequently, the moisture content distribution was implemented, as a second dimension to the popu- lation balance in this model. These two-dimensional simulations were able to describe the experimental data, especially the spread in the residual particle moisture distribution, much more accurately than one-dimensional simulations. Using this novel two-dimensional model, the effects of different operating parameters （process gas temperature, solid feed rate, superficial air velocity） on the particle moisture content distribution were systematically studied.
