Polishing is an important finishing process in die and mold manufacturing. Hand polishing takes long time and much labor. Efforts are made to automate the polishing process while keeping accuracy. Recently grinding ce...Polishing is an important finishing process in die and mold manufacturing. Hand polishing takes long time and much labor. Efforts are made to automate the polishing process while keeping accuracy. Recently grinding centers have been developed, which are used for free surface polishing in the present work. The new polishing technique applies the same cutting locus as used in the cutting process to remove only cusp height effectively, keeping the form accuracy generated in the cutting process.展开更多
Put forward a new kind of polishing method,ultrasonic magnetic abrasive fin-ishing(UMAF),and studied its mechanism of improving polishing efficiency.By analyzingall kind of forces acting on single abrasive particle in...Put forward a new kind of polishing method,ultrasonic magnetic abrasive fin-ishing(UMAF),and studied its mechanism of improving polishing efficiency.By analyzingall kind of forces acting on single abrasive particle in the polishing process and calculatingthe Size of the composition of forces,get the conclusion that UMAF will enhance the effi-ciency of the normal magnetic abrasive finishing(MAF)due to the ultrasonic vibration in-creases the cutting force and depth.At last the idea of designing the UMAF system basedon numerical control milling machine is put forward which is convenient to setup and willaccelerate the practical application of MAF.展开更多
Laser alloying was used for production of thick layers on surface of Nimonic 80A-alloy.For laser surface modification,three types of pre-coated pastes were applied:with amorphous boron,with amorphous boron and molybde...Laser alloying was used for production of thick layers on surface of Nimonic 80A-alloy.For laser surface modification,three types of pre-coated pastes were applied:with amorphous boron,with amorphous boron and molybdenum as well as with amorphous boron and niobium.The microstructure,hardness and wear resistance of produced layers were studied in details.The presence of different types of borides in re-melted zone depended on the paste composition and caused an increase in hardness up to about HV 1000.The wear resistance was evaluated by calculation of mass wear intensity factor Imw and relative mass loss of specimen and counter-specimen.The wear behavior of the tested frictional pairs was determined by 3D interference microscopy,scanning electron microscopy equipped with EDS microanalyzer.The significant increase in abrasive wear resistance was observed in comparison to untreated Nimonic 80A-alloy.The lowest mass loss intensity factor was characteristic of laser-alloyed Nimonic 80A-alloy with boron and niobium(Imw=1.234 mg/(cm2?h)).Laser alloyed-layers indicated abrasive wear mechanism with clearly visible grooves.Laser alloying with boron and niobium resulted in the additional oxidative wear mechanism.In this case,EDS patterns revealed presence of oxygen on the worn surface of specimen.展开更多
基金Project supported by the Natural Science Foundation of Shaanxi Province(Grant No.2006E112)
文摘Polishing is an important finishing process in die and mold manufacturing. Hand polishing takes long time and much labor. Efforts are made to automate the polishing process while keeping accuracy. Recently grinding centers have been developed, which are used for free surface polishing in the present work. The new polishing technique applies the same cutting locus as used in the cutting process to remove only cusp height effectively, keeping the form accuracy generated in the cutting process.
基金Supported by Ningbo Key Technology R&D Program(2005B100058)
文摘Put forward a new kind of polishing method,ultrasonic magnetic abrasive fin-ishing(UMAF),and studied its mechanism of improving polishing efficiency.By analyzingall kind of forces acting on single abrasive particle in the polishing process and calculatingthe Size of the composition of forces,get the conclusion that UMAF will enhance the effi-ciency of the normal magnetic abrasive finishing(MAF)due to the ultrasonic vibration in-creases the cutting force and depth.At last the idea of designing the UMAF system basedon numerical control milling machine is put forward which is convenient to setup and willaccelerate the practical application of MAF.
基金financially supported within the project "Engineer of the Future.Improving the didactic potential of the Poznan University of Technology"-POKL.04.03.00-00-259/12,implemented within the Human Capital Operational Programme,co-financed by the European Union within the European Social Fundby Ministry of Science and Higher Education in Poland as a part of the 02/24/DSPB project
文摘Laser alloying was used for production of thick layers on surface of Nimonic 80A-alloy.For laser surface modification,three types of pre-coated pastes were applied:with amorphous boron,with amorphous boron and molybdenum as well as with amorphous boron and niobium.The microstructure,hardness and wear resistance of produced layers were studied in details.The presence of different types of borides in re-melted zone depended on the paste composition and caused an increase in hardness up to about HV 1000.The wear resistance was evaluated by calculation of mass wear intensity factor Imw and relative mass loss of specimen and counter-specimen.The wear behavior of the tested frictional pairs was determined by 3D interference microscopy,scanning electron microscopy equipped with EDS microanalyzer.The significant increase in abrasive wear resistance was observed in comparison to untreated Nimonic 80A-alloy.The lowest mass loss intensity factor was characteristic of laser-alloyed Nimonic 80A-alloy with boron and niobium(Imw=1.234 mg/(cm2?h)).Laser alloyed-layers indicated abrasive wear mechanism with clearly visible grooves.Laser alloying with boron and niobium resulted in the additional oxidative wear mechanism.In this case,EDS patterns revealed presence of oxygen on the worn surface of specimen.
