The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid＇s washing ability. Discharge characte...The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid＇s washing ability. Discharge characteristics and theoretic analysis between two electrodes are also discussed based on discharge waveform. By using composite cooling liquid which has strong washing ability, the efficiency in the first stable cutting phase has reached more than 200 mm^2/min, and the roughness of the surface has reached Ra〈0.8 μm after the fourth cutting with more than 50 mm^2/min average cutting efficiency. It is pointed out that cutting situation of the wire cut electrical discharge machine with high wire traveling speed （HSWEDM） is better than the wire cut electrical discharge machine with low wire traveling speed （LSWEDM） in the condition of improving the cooling liquid washing ability. The machining indices of HSWEDM will be increased remarkably by using the composite cooling liquid.展开更多
Through the comparison study on cutting force, cutting temperature andmachined surface quality with the sub-dry cutting traditional cooling method, it is shown thatsub-dry cutting can retard the wear of the tooled par...Through the comparison study on cutting force, cutting temperature andmachined surface quality with the sub-dry cutting traditional cooling method, it is shown thatsub-dry cutting can retard the wear of the tooled parts. It is beneficial to realize the productionwithout pollution and meet the demand of clean environment.展开更多
The effects of cryogenic cooling on cutting forces in the milling process of AISI 304 stainless steel were investigated experimentally.Cryogenic cooling was achieved by spraying liquid nitrogen to tool,chips and mater...The effects of cryogenic cooling on cutting forces in the milling process of AISI 304 stainless steel were investigated experimentally.Cryogenic cooling was achieved by spraying liquid nitrogen to tool,chips and material interfaces using a pipe with an internal diameter of 1 mm;the flow rate of liquid nitrogen was 5.2 L/min;two cutting directions（climbing and conventional milling）,two machining conditions（dry and cryogenic cooling） and four cutting speeds（80,120,160 and 200 m/min） were used in the milling process.Cryogenic cooling and cutting speed are found to be effective on cutting forces.Cutting forces and torque in cryogenic milling are higher than those in dry milling.Cutting force is increased as the cutting speed is increased.Tool fritter around insert nose radius is the main problem of climb milling method in cryogenic cooling at low cutting speeds.展开更多
The efective removal of the heat generated during mechanical cutting processes is crucial to enhancing tool life and produc-ing workpieces with superior surface fnish.The internal cooling systems used in cutting inser...The efective removal of the heat generated during mechanical cutting processes is crucial to enhancing tool life and produc-ing workpieces with superior surface fnish.The internal cooling systems used in cutting inserts employ a liquid water-based solvent as the primary medium to transport the excess thermal energy generated during the cutting process.The limitations of this approach are the low thermal conductivity of water and the need for a mechanical input to circulate the coolant around the inner chamber of the cutting tool.In this context,this paper proposes an alternative method in which liquid gallium is used as the coolant in combination with a magnetohydrodynamic(MHD)pump,which avoids the need for an external power source.Using computational fuid dynamics,we created a numerical model of an internal cooling system and then solved it under conditions in which a magnetic feld was applied to the liquid metal.This was followed by a simulation study performed to evaluate the efectiveness of liquid gallium over liquid water.The results of experiments conducted under non-cooling and liquid gallium cooling conditions were analyzed and compared in terms of the tool wear rate.The results showed that after six machining cycles at a cutting speed Vc=250 m min−1,the corner wear VBc rate was 75µm with the coolant of and 48µm with the MHD-based coolant on,representing a decrease of 36%in tool wear.At Vc=900 m min−1,the corner wear VBc rate was 75µm with the coolant of and 246µm with the MHD-based coolant on,representing a decrease of 31%in tool wear.When external cooling using liquid water was added,the results showed at Vc=250 m min−1,the diference between the tool wear rate reduction with the internal liquid gallium coolant relative to the external coolant was 29%.When the cutting speed was increased to Vc=900 m min−1,the diference observed between the internal liquid gallium coolant relative to the external coolant was 16%.The study proves the feasibility of using liquid gallium as a coolant to efectively remove thermal energy through internally fabricated cooling channels in cutting inserts.展开更多
基金Provincial Key Laboratory of Precision and Micro-Manufacturing Technology of Jiangsu,China(No.Z0601-052-02).
文摘The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid＇s washing ability. Discharge characteristics and theoretic analysis between two electrodes are also discussed based on discharge waveform. By using composite cooling liquid which has strong washing ability, the efficiency in the first stable cutting phase has reached more than 200 mm^2/min, and the roughness of the surface has reached Ra〈0.8 μm after the fourth cutting with more than 50 mm^2/min average cutting efficiency. It is pointed out that cutting situation of the wire cut electrical discharge machine with high wire traveling speed （HSWEDM） is better than the wire cut electrical discharge machine with low wire traveling speed （LSWEDM） in the condition of improving the cooling liquid washing ability. The machining indices of HSWEDM will be increased remarkably by using the composite cooling liquid.
基金Foundation of East China Shipbuilding Institute(No.Y98205).
文摘Through the comparison study on cutting force, cutting temperature andmachined surface quality with the sub-dry cutting traditional cooling method, it is shown thatsub-dry cutting can retard the wear of the tooled parts. It is beneficial to realize the productionwithout pollution and meet the demand of clean environment.
基金the Scientific and Technological Research Council of Turkey(TUBITAK)for providing the financial support of the cryogenic machining project(Project No.106M473)
文摘The effects of cryogenic cooling on cutting forces in the milling process of AISI 304 stainless steel were investigated experimentally.Cryogenic cooling was achieved by spraying liquid nitrogen to tool,chips and material interfaces using a pipe with an internal diameter of 1 mm;the flow rate of liquid nitrogen was 5.2 L/min;two cutting directions（climbing and conventional milling）,two machining conditions（dry and cryogenic cooling） and four cutting speeds（80,120,160 and 200 m/min） were used in the milling process.Cryogenic cooling and cutting speed are found to be effective on cutting forces.Cutting forces and torque in cryogenic milling are higher than those in dry milling.Cutting force is increased as the cutting speed is increased.Tool fritter around insert nose radius is the main problem of climb milling method in cryogenic cooling at low cutting speeds.
基金The acknowledgement also goes to the“111”Project by the State Admin-istration of Foreign Experts Afairs and the Ministry of Education of China(No.B07014).
文摘The efective removal of the heat generated during mechanical cutting processes is crucial to enhancing tool life and produc-ing workpieces with superior surface fnish.The internal cooling systems used in cutting inserts employ a liquid water-based solvent as the primary medium to transport the excess thermal energy generated during the cutting process.The limitations of this approach are the low thermal conductivity of water and the need for a mechanical input to circulate the coolant around the inner chamber of the cutting tool.In this context,this paper proposes an alternative method in which liquid gallium is used as the coolant in combination with a magnetohydrodynamic(MHD)pump,which avoids the need for an external power source.Using computational fuid dynamics,we created a numerical model of an internal cooling system and then solved it under conditions in which a magnetic feld was applied to the liquid metal.This was followed by a simulation study performed to evaluate the efectiveness of liquid gallium over liquid water.The results of experiments conducted under non-cooling and liquid gallium cooling conditions were analyzed and compared in terms of the tool wear rate.The results showed that after six machining cycles at a cutting speed Vc=250 m min−1,the corner wear VBc rate was 75µm with the coolant of and 48µm with the MHD-based coolant on,representing a decrease of 36%in tool wear.At Vc=900 m min−1,the corner wear VBc rate was 75µm with the coolant of and 246µm with the MHD-based coolant on,representing a decrease of 31%in tool wear.When external cooling using liquid water was added,the results showed at Vc=250 m min−1,the diference between the tool wear rate reduction with the internal liquid gallium coolant relative to the external coolant was 29%.When the cutting speed was increased to Vc=900 m min−1,the diference observed between the internal liquid gallium coolant relative to the external coolant was 16%.The study proves the feasibility of using liquid gallium as a coolant to efectively remove thermal energy through internally fabricated cooling channels in cutting inserts.
