Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutti...Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.展开更多
In this study,magnetic abrasives were obtained by crushing and sieving sintered iron-silicon carbide(Fe-SiC)composites.Fe and SiC powders with different mesh numbers were pre-compacted using different pressures and th...In this study,magnetic abrasives were obtained by crushing and sieving sintered iron-silicon carbide(Fe-SiC)composites.Fe and SiC powders with different mesh numbers were pre-compacted using different pressures and then sintered at various temperatures and with different holding times.The dispersion uniformity of the SiC powder was improved through surface modification using polyethylene glycol(PEG)300.The resulting magnetic abrasives were characterized in terms of phase composition,density,relative permeability,and microstructure;this was followed by a comprehensive analysis to reveal the optimal processing parameters.The ideal combination of process parameters for preparing SiC magnetic-abrasive grains for the magnetic induction-wire sawing process was obtained,which are preparation load of 60 kN,a SiC mesh number of 1,500,a sintering temperature of 1100℃,and a holding time of 4 h.展开更多
The advantages, such as a small cutting force, narrow kerf and little material waste make wire saw cut- ting suitable for machining precious materials like SiC, Si monocrystal and a variety of gem. As regards wire saw...The advantages, such as a small cutting force, narrow kerf and little material waste make wire saw cut- ting suitable for machining precious materials like SiC, Si monocrystal and a variety of gem. As regards wire saw cutting fo wafer, however, in traditional wire saw cutting process, the cutting efficiency is low, the wear of wire saw is badly, the surface roughness of wafer is poor etc, which have a seriously impact on the cutting process stability and the use of wafers. Ultrasonic-assisted machining method is very suitable for processing a variety of non-conduc- tive hard and brittle materials, glass, ceramics, quartz, silicon, precious stones and diamonds, etc. In this paper, the force model of ultrusonic-assisted wire saw cutting of SiC monocrystal wafer, based on the kinematic and experi- mental analysis were established. The single factor and orthogonal experimental scheme for different processing pa- rameters such as wire saw speed, part rotation speed of and part feed rate, were carried out in traditional wire saw and ultrasonic-assisted wire saw cutting process. The multiple linear regression method is used to establish the static model among the cutting force, processing parameters and ultrasonic vibration parameters, and the model signifi- cance is verified. The results show, as regards ultrasonic-assisted wire saw cutting of SiC monicrystal wafer, both the tangential and normal cutting forces can reduce about 24. 5%-36% and 36. 6%-40%.展开更多
The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite elem...The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite element method. It shows that the cutting stress is uniformly distributed along the direction of the workpiece width in the steady state. A mathematical equation of sawing trajectory was established by using the superposition principle and the cutting experiment of wire saw to calculate the cutting trajectory. The comparison of the theoretical trajectory with the calculated one indicates that the error is less than 15%. The research results provide a theoretic basis for optimization of the saw's cutting process parameters.展开更多
Based on the measured thermal cycle of double-wire submerged arc welding （SAW）, the gleeble thermal test was performed. Meanwhile, the Charpy V-notch impact test at -50 ℃ and hardness test at room temperature were ...Based on the measured thermal cycle of double-wire submerged arc welding （SAW）, the gleeble thermal test was performed. Meanwhile, the Charpy V-notch impact test at -50 ℃ and hardness test at room temperature were carried out after the thermal test. Thermally cycled microstructure and fracture surfaces were observed too. The results indicate that impact toughness of heat-affected zone （HAZ） at -50 ℃ is lower than that of parent metal with different wire spacing and welding speed. The microstracture of coarse-grains heat-affected zone （ CGHAZ ） is mainly made up of lath bainite with serious brittleness. The study also shows that a smaller energy input could be adopted to ensure the toughness of welded joints at the welding process in a common molten pool, while a higher energy input could be exerted to enhance welding efficieney at the welding process in two separate molten pools.展开更多
Grains in the slurry can be brought into cutting zone by steel wire with a certain speed to achieve the purpose of removing the workpiece material in the free abrasive wire sawing machining. Because its own of multi- ...Grains in the slurry can be brought into cutting zone by steel wire with a certain speed to achieve the purpose of removing the workpiece material in the free abrasive wire sawing machining. Because its own of multi- strands characteristics, we use it to replace the steel wire to do slicing experiment. In this paper, multi-strands wire is made by seven metal wires and has many grooves on its surface. Compared with steel wire, it can carry more grains into cutting zone which is conducive to improving the slicing efficiency. We do some comparative slic- ing experimcnts by applying multi-strands wire （~b0.25 mm） and steel wire （~b0.25 mm） to cut optical glass （K9）. The results show that slicing efficiency and the surface roughness of the workpiece sliced by using multi-strands wire are better than that by using steel wire. but the kerf width of the former is wider than that of the latter in the same experimental conditions.展开更多
The twin-wire SAW welding process was investigated using Baosteel 70 kg class high strength steel, and the properties of the joints were studied using conventional single and double-faced grooves as well as an optimiz...The twin-wire SAW welding process was investigated using Baosteel 70 kg class high strength steel, and the properties of the joints were studied using conventional single and double-faced grooves as well as an optimized groove. The results showed that by using an optimized double-faced groove, a small root face, and no back gouging, a small welding heat input was achieved and thus the joint strength and toughness were improved significantly. Also, removing back gouging reduced the labor required in the process. The weld reinforcement and deformation were observed to be rather small.展开更多
Based on the analysis of the mechanism of wire tension control by using torque motors in the multi-wire saw machining process, some mathematical models of a tension control system are studied, and an adaptive algo- ri...Based on the analysis of the mechanism of wire tension control by using torque motors in the multi-wire saw machining process, some mathematical models of a tension control system are studied, and an adaptive algo- rithm is designed for controlling the wire tension. In this algorithm of tension control, the rotation speeds and waving angle of motors are measured and fed back to the controller, and the NLMS（ normalized least mean squares） algorithm is used to calculate the adaptive correction value and control the wire tension accurately. The computer simulation results in Matlab software validate the high accuracy for controlling the system of the wire tension with the NLMS algorithm in the multi-wire saw machining process.展开更多
The influence of different technological parameter on material remove rate and surface quality of ZrO2 ceramics is studied using the cutting machining method of electroplate diamond wire saw with ultrasonic vibration....The influence of different technological parameter on material remove rate and surface quality of ZrO2 ceramics is studied using the cutting machining method of electroplate diamond wire saw with ultrasonic vibration.Experimental results show that,compared with the same experiment condition without ultrasonic vibration,this cutting method has the advantages of high material remove rate,good surface quality,little brokenness and so on.展开更多
Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances o...Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances of brazed diamond wire have been reported, seldom do these studies refer to its process characteristics. Sawing performances of a brazed diamond wire are investigated and compared with those of a sintered diamond wire on a wire saw machine. The surface topographies of beads selected from the two wires are micro observed before sawing. The sawing tests are carried out in constant feed rate feeding（CFF） and constant normal force feeding（CNFF）. In CFF test, sawing force, power, and the cut depths of positions on contact curve are measured. Then, coupled with the observations of beads topographies, sawing force and its ratio, relations of power against material removal rate, and contact curve linearity are compared and discussed. In CNFF test, the sawing rates of the two wires are investigated. The results indicate that the brazed wire performs with lower sawing force（less 16% of tangential force and 28% of normal force）, more energy efficiency（nearly one-fifth of sawing power is saved）, at a higher sawing rate （the rate is doubled） and with better contact curve linearity as compared with the sintered wire. This proposed research experimentally evaluates the sawing performances of brazed diamond wire from the aspect of process parameters, which can provide a basis for popularizing the brazed diamond wire.展开更多
The diamond wire-sawing process was developed to cut granite in both quarries and block processing plants.In this paper,swarf was collected from different areas along the sawing arc when sawing three granites.The part...The diamond wire-sawing process was developed to cut granite in both quarries and block processing plants.In this paper,swarf was collected from different areas along the sawing arc when sawing three granites.The particle size distribution and the morphology of the swarf were investigated systematically,along with the swarf formation mechanism in sawing.Granite swarf formation was dominated by transgranular fractures based on the morphology of sawn granite chips and the analysis of sawn chip size.A long cutting arc increased the movement among the swarf,tool,and workpiece,thereby inducing a secondary fracture in the sawn chip.展开更多
基金Sponsored by Liaoning Innovation Team Fundation(2008T164)
文摘Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.
基金supported by Talents Introduction Research Projects of NBPT[Grant Number RC201807]the National Nature Science Foundation of China(NSFC)[Grant Number 51475427].
文摘In this study,magnetic abrasives were obtained by crushing and sieving sintered iron-silicon carbide(Fe-SiC)composites.Fe and SiC powders with different mesh numbers were pre-compacted using different pressures and then sintered at various temperatures and with different holding times.The dispersion uniformity of the SiC powder was improved through surface modification using polyethylene glycol(PEG)300.The resulting magnetic abrasives were characterized in terms of phase composition,density,relative permeability,and microstructure;this was followed by a comprehensive analysis to reveal the optimal processing parameters.The ideal combination of process parameters for preparing SiC magnetic-abrasive grains for the magnetic induction-wire sawing process was obtained,which are preparation load of 60 kN,a SiC mesh number of 1,500,a sintering temperature of 1100℃,and a holding time of 4 h.
基金supported by National Natural Science Foundation of China under Grant No.51175420Shaanxi Province Education Office under Grant No.11JK0849/11JS074
文摘The advantages, such as a small cutting force, narrow kerf and little material waste make wire saw cut- ting suitable for machining precious materials like SiC, Si monocrystal and a variety of gem. As regards wire saw cutting fo wafer, however, in traditional wire saw cutting process, the cutting efficiency is low, the wear of wire saw is badly, the surface roughness of wafer is poor etc, which have a seriously impact on the cutting process stability and the use of wafers. Ultrasonic-assisted machining method is very suitable for processing a variety of non-conduc- tive hard and brittle materials, glass, ceramics, quartz, silicon, precious stones and diamonds, etc. In this paper, the force model of ultrusonic-assisted wire saw cutting of SiC monocrystal wafer, based on the kinematic and experi- mental analysis were established. The single factor and orthogonal experimental scheme for different processing pa- rameters such as wire saw speed, part rotation speed of and part feed rate, were carried out in traditional wire saw and ultrasonic-assisted wire saw cutting process. The multiple linear regression method is used to establish the static model among the cutting force, processing parameters and ultrasonic vibration parameters, and the model signifi- cance is verified. The results show, as regards ultrasonic-assisted wire saw cutting of SiC monicrystal wafer, both the tangential and normal cutting forces can reduce about 24. 5%-36% and 36. 6%-40%.
基金Sponsored by Innovation team item fund of Liaoning Province ( 2008T164)
文摘The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite element method. It shows that the cutting stress is uniformly distributed along the direction of the workpiece width in the steady state. A mathematical equation of sawing trajectory was established by using the superposition principle and the cutting experiment of wire saw to calculate the cutting trajectory. The comparison of the theoretical trajectory with the calculated one indicates that the error is less than 15%. The research results provide a theoretic basis for optimization of the saw's cutting process parameters.
文摘Based on the measured thermal cycle of double-wire submerged arc welding （SAW）, the gleeble thermal test was performed. Meanwhile, the Charpy V-notch impact test at -50 ℃ and hardness test at room temperature were carried out after the thermal test. Thermally cycled microstructure and fracture surfaces were observed too. The results indicate that impact toughness of heat-affected zone （HAZ） at -50 ℃ is lower than that of parent metal with different wire spacing and welding speed. The microstracture of coarse-grains heat-affected zone （ CGHAZ ） is mainly made up of lath bainite with serious brittleness. The study also shows that a smaller energy input could be adopted to ensure the toughness of welded joints at the welding process in a common molten pool, while a higher energy input could be exerted to enhance welding efficieney at the welding process in two separate molten pools.
基金National Natural Science Foundation of China(No.51075367)Natural Science Foundation of Zhejiang Province(No.Y1090931)
文摘Grains in the slurry can be brought into cutting zone by steel wire with a certain speed to achieve the purpose of removing the workpiece material in the free abrasive wire sawing machining. Because its own of multi- strands characteristics, we use it to replace the steel wire to do slicing experiment. In this paper, multi-strands wire is made by seven metal wires and has many grooves on its surface. Compared with steel wire, it can carry more grains into cutting zone which is conducive to improving the slicing efficiency. We do some comparative slic- ing experimcnts by applying multi-strands wire （~b0.25 mm） and steel wire （~b0.25 mm） to cut optical glass （K9）. The results show that slicing efficiency and the surface roughness of the workpiece sliced by using multi-strands wire are better than that by using steel wire. but the kerf width of the former is wider than that of the latter in the same experimental conditions.
文摘The twin-wire SAW welding process was investigated using Baosteel 70 kg class high strength steel, and the properties of the joints were studied using conventional single and double-faced grooves as well as an optimized groove. The results showed that by using an optimized double-faced groove, a small root face, and no back gouging, a small welding heat input was achieved and thus the joint strength and toughness were improved significantly. Also, removing back gouging reduced the labor required in the process. The weld reinforcement and deformation were observed to be rather small.
基金supported by the National Natural Science Fundproject (50775207)Key Laboratory of E & M (Zhejiang University of Technology) Open Fund project (2009EP017)
文摘Based on the analysis of the mechanism of wire tension control by using torque motors in the multi-wire saw machining process, some mathematical models of a tension control system are studied, and an adaptive algo- rithm is designed for controlling the wire tension. In this algorithm of tension control, the rotation speeds and waving angle of motors are measured and fed back to the controller, and the NLMS（ normalized least mean squares） algorithm is used to calculate the adaptive correction value and control the wire tension accurately. The computer simulation results in Matlab software validate the high accuracy for controlling the system of the wire tension with the NLMS algorithm in the multi-wire saw machining process.
基金Sponsored by Department of Education University Research Project of Liaoning Province(LN566)
文摘The influence of different technological parameter on material remove rate and surface quality of ZrO2 ceramics is studied using the cutting machining method of electroplate diamond wire saw with ultrasonic vibration.Experimental results show that,compared with the same experiment condition without ultrasonic vibration,this cutting method has the advantages of high material remove rate,good surface quality,little brokenness and so on.
基金supported by National Natural Science Foundation of China(Grant Nos. 51235004, 51105148, 51175194)Program for Changjiang Scholars and Innovative Research Team in University of China(Grant No. IRT1063)
文摘Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances of brazed diamond wire have been reported, seldom do these studies refer to its process characteristics. Sawing performances of a brazed diamond wire are investigated and compared with those of a sintered diamond wire on a wire saw machine. The surface topographies of beads selected from the two wires are micro observed before sawing. The sawing tests are carried out in constant feed rate feeding（CFF） and constant normal force feeding（CNFF）. In CFF test, sawing force, power, and the cut depths of positions on contact curve are measured. Then, coupled with the observations of beads topographies, sawing force and its ratio, relations of power against material removal rate, and contact curve linearity are compared and discussed. In CNFF test, the sawing rates of the two wires are investigated. The results indicate that the brazed wire performs with lower sawing force（less 16% of tangential force and 28% of normal force）, more energy efficiency（nearly one-fifth of sawing power is saved）, at a higher sawing rate （the rate is doubled） and with better contact curve linearity as compared with the sintered wire. This proposed research experimentally evaluates the sawing performances of brazed diamond wire from the aspect of process parameters, which can provide a basis for popularizing the brazed diamond wire.
文摘The diamond wire-sawing process was developed to cut granite in both quarries and block processing plants.In this paper,swarf was collected from different areas along the sawing arc when sawing three granites.The particle size distribution and the morphology of the swarf were investigated systematically,along with the swarf formation mechanism in sawing.Granite swarf formation was dominated by transgranular fractures based on the morphology of sawn granite chips and the analysis of sawn chip size.A long cutting arc increased the movement among the swarf,tool,and workpiece,thereby inducing a secondary fracture in the sawn chip.
