To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal q...To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal quantity lubrication（MQL）,cryogenic MQL,and ionized air as the cooling/lubrication conditions are studied.Experimental results show that at speed 120 m/min turning Ti6Al4V,the cutting force under ionized air is smallest under all lubricant conditions,and tool life is best,next is cryogenic MQL.MQL and cold air almost have the same effect,a little better than dry.Meanwhile the smallest surface roughness is also obtained under ionized air condition.Flank wear and crater wear are the dominant failure modes when high-speed turning Ti6Al4V by SEM analysis.Finally the conclusion is drawn that ionized air and cryogenic MQL have better cooling/lubrication effects and can effectively improve the tool life.展开更多
Using fluid dynamics software Fluent, the spray characteristics of an effervescent atomizer in a downstream flow field was simulated and analyzed, the results show that on the cross sections of the atomizer downstream...Using fluid dynamics software Fluent, the spray characteristics of an effervescent atomizer in a downstream flow field was simulated and analyzed, the results show that on the cross sections of the atomizer downstream flow field, the distribution of the atomized droplet size is small and mainly concentrated about Sauter mean diameter （ SMD）, and the distribution of the axial velocity is large, but mainly concentrated about the gas peak velocity in the closer nozzle axis area; the gas peak velocity of the atomized droplet increases, while the droplet SMD decreases with increase of the nozzle caliber and the air pressure; with the increase of the flow rate of cuttingfluid, the atomized droplet SMD increases, while the gas peak velocity rises first and then decreases, but the decrease trend is very small after the air pressure is more than 0. 4 MPa. The simulation results have significance in guiding for designing and applying the effervescent atomizer.展开更多
基金Supported by the National Natural Science Foundation of China(50975141,51005118)~~
文摘To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal quantity lubrication（MQL）,cryogenic MQL,and ionized air as the cooling/lubrication conditions are studied.Experimental results show that at speed 120 m/min turning Ti6Al4V,the cutting force under ionized air is smallest under all lubricant conditions,and tool life is best,next is cryogenic MQL.MQL and cold air almost have the same effect,a little better than dry.Meanwhile the smallest surface roughness is also obtained under ionized air condition.Flank wear and crater wear are the dominant failure modes when high-speed turning Ti6Al4V by SEM analysis.Finally the conclusion is drawn that ionized air and cryogenic MQL have better cooling/lubrication effects and can effectively improve the tool life.
文摘Using fluid dynamics software Fluent, the spray characteristics of an effervescent atomizer in a downstream flow field was simulated and analyzed, the results show that on the cross sections of the atomizer downstream flow field, the distribution of the atomized droplet size is small and mainly concentrated about Sauter mean diameter （ SMD）, and the distribution of the axial velocity is large, but mainly concentrated about the gas peak velocity in the closer nozzle axis area; the gas peak velocity of the atomized droplet increases, while the droplet SMD decreases with increase of the nozzle caliber and the air pressure; with the increase of the flow rate of cuttingfluid, the atomized droplet SMD increases, while the gas peak velocity rises first and then decreases, but the decrease trend is very small after the air pressure is more than 0. 4 MPa. The simulation results have significance in guiding for designing and applying the effervescent atomizer.
