Dry sliding wear behaviour of stir-cast aluminium matrix composites(AMCs)containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated.Two different ceramic particle reinforcements were used ...Dry sliding wear behaviour of stir-cast aluminium matrix composites(AMCs)containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated.Two different ceramic particle reinforcements were used separately:synthetic ceramic particles(B_(4)C),and natural ceramic particles(ilmenite).Optical micrographs showed uniform dispersion of reinforced particles in the matrix material.Reinforced particles refined the grain size of eutectic silicon and changed its morphology to globular type.B_(4)C reinforced composites(BRCs)showed maximum improvement in hardness of AMCs.Ilmenite reinforced composites(IRCs)showed maximum reduction in coefficient of friction values due to strong matrix−reinforcement interfacial bonding caused by the formation of interfacial compounds.Dry sliding wear behaviour of composites was significantly improved as compared to base alloy.The low density and high hardness of B_(4)C particles resulted in high dislocation density around filler particles in BRCs.On the other hand,the low thermal conductivity of ilmenite particles resulted in early oxidation and formation of a tribo-layer on surface of IRCs.So,both types of reinforcements led to the improvement in wear properties of AMCs,though the mechanisms involved were very different.Thus,the low-cost ilmenite particles can be used as alternative fillers to the high-cost B_(4)C particles for processing of wear resistant composites.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
A STUDY OF A L1NEAR COMPRESSOR WITH A GAS SPRING；LINEAR RESONANCE COMPRESSOR DRIVEN BY A VARIABLE GAPRELUCTANCE LINEAR MOTOR；Method for estimating cargo damage during truck transpoortation；Micro wear tests by using...A STUDY OF A L1NEAR COMPRESSOR WITH A GAS SPRING；LINEAR RESONANCE COMPRESSOR DRIVEN BY A VARIABLE GAPRELUCTANCE LINEAR MOTOR；Method for estimating cargo damage during truck transpoortation；Micro wear tests by using atomic force microscope:relationship between contact area and pull-off force；Relation between friction and plastic deformation examined by using periodic asperity arrays fabricated on an AFM multipurpose cantilever……展开更多
The work described in this paper is part of the European Project IBIOLAB, trying to find suitable metalworking fluids based on vegetable oils, such us High Oleic Sunflower Oil （HOSO）. In this paper, the performance ...The work described in this paper is part of the European Project IBIOLAB, trying to find suitable metalworking fluids based on vegetable oils, such us High Oleic Sunflower Oil （HOSO）. In this paper, the performance of the newly developed IBIOLAB water based formulations supplied by SOGELUB and LUBRIX is analyzed and compared with reference Mineral and Synthetic cutting fluids Innovative characterization tests at laboratory scale （3 ball abrasion tests, grinding simulation tests, Tapping torque test） in real grinding machines in combination with advanced characterization techniques （residual stress measurements monitored by RX to predict formation of cracks）, have been used for screening the performance of the emulsions.展开更多
文摘Dry sliding wear behaviour of stir-cast aluminium matrix composites(AMCs)containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated.Two different ceramic particle reinforcements were used separately:synthetic ceramic particles(B_(4)C),and natural ceramic particles(ilmenite).Optical micrographs showed uniform dispersion of reinforced particles in the matrix material.Reinforced particles refined the grain size of eutectic silicon and changed its morphology to globular type.B_(4)C reinforced composites(BRCs)showed maximum improvement in hardness of AMCs.Ilmenite reinforced composites(IRCs)showed maximum reduction in coefficient of friction values due to strong matrix−reinforcement interfacial bonding caused by the formation of interfacial compounds.Dry sliding wear behaviour of composites was significantly improved as compared to base alloy.The low density and high hardness of B_(4)C particles resulted in high dislocation density around filler particles in BRCs.On the other hand,the low thermal conductivity of ilmenite particles resulted in early oxidation and formation of a tribo-layer on surface of IRCs.So,both types of reinforcements led to the improvement in wear properties of AMCs,though the mechanisms involved were very different.Thus,the low-cost ilmenite particles can be used as alternative fillers to the high-cost B_(4)C particles for processing of wear resistant composites.
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.
文摘A STUDY OF A L1NEAR COMPRESSOR WITH A GAS SPRING；LINEAR RESONANCE COMPRESSOR DRIVEN BY A VARIABLE GAPRELUCTANCE LINEAR MOTOR；Method for estimating cargo damage during truck transpoortation；Micro wear tests by using atomic force microscope:relationship between contact area and pull-off force；Relation between friction and plastic deformation examined by using periodic asperity arrays fabricated on an AFM multipurpose cantilever……
文摘The work described in this paper is part of the European Project IBIOLAB, trying to find suitable metalworking fluids based on vegetable oils, such us High Oleic Sunflower Oil （HOSO）. In this paper, the performance of the newly developed IBIOLAB water based formulations supplied by SOGELUB and LUBRIX is analyzed and compared with reference Mineral and Synthetic cutting fluids Innovative characterization tests at laboratory scale （3 ball abrasion tests, grinding simulation tests, Tapping torque test） in real grinding machines in combination with advanced characterization techniques （residual stress measurements monitored by RX to predict formation of cracks）, have been used for screening the performance of the emulsions.
