The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron.However,the machining adaptability of various coating materials to malleable cast iron has been insufficiently r...The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron.However,the machining adaptability of various coating materials to malleable cast iron has been insufficiently researched.In this paper,turning tests were conducted on cemented carbide tools with different coatings(a thick TiN/TiAlN coating,a thin TiN/TiAlN coating,and a nanocomposite(nc)TiAlSiN coating).All coatings were applied by physical vapor deposition.In a comparative study of chip morphology,cutting force,cutting temperature,specific cutting energy,tool wear,and surface roughness,this study analyzed the cutting characteristics of the tools coated with various materials,and established the relationship between the cutting parameters and machining objectives.The results showed that in malleable cast iron machining,the coating material significantly affects the cutting performance of the tool.Among the three tools,the nc-TiAlSiN-coated carbide tool achieved the minimum cutting force,the lowest cutting temperature,least tool wear,longest tool life,and best surface quality.Moreover,in comparisons between cemented-carbide and compacted-graphite cast iron machined under the same conditions,the wear mechanism of the coated tools was found to depend on the cast iron being machined.Therefore,the performance requirements of a tool depend on multiple factors,and selecting an appropriately coated tool for a particular cast iron material is essential.展开更多
Vibration-assisted machining(VAM) has the advantages of extending tool life,reducing cutting force and improving the surface finish.Implementation of vibration assistance with high frequency and amplitude is still a c...Vibration-assisted machining(VAM) has the advantages of extending tool life,reducing cutting force and improving the surface finish.Implementation of vibration assistance with high frequency and amplitude is still a challenge,especially for a micro-milling process.In this paper,a new 2D vibration stage for vibration-assisted micro-milling is developed.The kinematics of the milling process with vibration assistance is modeled,and the effects of vibration parameters on the periodic tool-workpiece separation(TWS) is analyzed.The structure of the vibration stage is designed with flexure hinges,and two piezoelectric actuators are used to drive the stage in two directions.An amplifier is integrated into the vibration stage,and the dynamics of the whole vibration system are identified and analyzed.Micro-milling experiments are conducted to determine the effects of vibration assistance on cutting force and surface quality.展开更多
基金Supported by National Major Science and Technology Projects of China(Grant No.SK201901A31-04)Key Program of NSFC-Guangdong Joint Fund,China(Grant No.U1201245).
文摘The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron.However,the machining adaptability of various coating materials to malleable cast iron has been insufficiently researched.In this paper,turning tests were conducted on cemented carbide tools with different coatings(a thick TiN/TiAlN coating,a thin TiN/TiAlN coating,and a nanocomposite(nc)TiAlSiN coating).All coatings were applied by physical vapor deposition.In a comparative study of chip morphology,cutting force,cutting temperature,specific cutting energy,tool wear,and surface roughness,this study analyzed the cutting characteristics of the tools coated with various materials,and established the relationship between the cutting parameters and machining objectives.The results showed that in malleable cast iron machining,the coating material significantly affects the cutting performance of the tool.Among the three tools,the nc-TiAlSiN-coated carbide tool achieved the minimum cutting force,the lowest cutting temperature,least tool wear,longest tool life,and best surface quality.Moreover,in comparisons between cemented-carbide and compacted-graphite cast iron machined under the same conditions,the wear mechanism of the coated tools was found to depend on the cast iron being machined.Therefore,the performance requirements of a tool depend on multiple factors,and selecting an appropriately coated tool for a particular cast iron material is essential.
基金supported by NSERC-Discovery FundsRGPIN-2018-04911partly supported by China Scholarship Council.
文摘Vibration-assisted machining(VAM) has the advantages of extending tool life,reducing cutting force and improving the surface finish.Implementation of vibration assistance with high frequency and amplitude is still a challenge,especially for a micro-milling process.In this paper,a new 2D vibration stage for vibration-assisted micro-milling is developed.The kinematics of the milling process with vibration assistance is modeled,and the effects of vibration parameters on the periodic tool-workpiece separation(TWS) is analyzed.The structure of the vibration stage is designed with flexure hinges,and two piezoelectric actuators are used to drive the stage in two directions.An amplifier is integrated into the vibration stage,and the dynamics of the whole vibration system are identified and analyzed.Micro-milling experiments are conducted to determine the effects of vibration assistance on cutting force and surface quality.
