Three-beam laser internal coaxial wire feeding cladding is regarded as a promising additive manufacturing technique because it is highly efficient and controllable.In this study,the effects of the defocus distance on ...Three-beam laser internal coaxial wire feeding cladding is regarded as a promising additive manufacturing technique because it is highly efficient and controllable.In this study,the effects of the defocus distance on cladding using a three-beam laser with internal wire feeding are experimentally and numerically studied.A process map indicating the surface characteristics at different defocus distances with various parameter combinations was developed.The transmission characteristics including laser intensity,beam size,and laser spot distance of the three-beam laser at different defocus distances were analyzed using TracePro software.Based on the TracePro results as heat source,a three-dimensional transient finite element(FE)thermal model was formulated to predict the thermal field,temperature history and molten pool shape at different defocus distances.A molten pool with a flat bottom and low melting depth is generated when the defocus distance is−2.5 mm,whereas when this distance is−1.5 mm,a pool with a valley-shaped bond and high melting depth is formed.The simulated results of the temperature cycle and clad geometry are both validated and found to well agree with experimental measurements.The influence of the defocus distance on the microstructure and microhardness are discussed based on the temperature history and cooling rate.With the increase in the absolute defocus distance,the height and dilution of the clad decreased,whereas the width increased.In addition,the effects of defocus distance with various parameter combinations on clad geometry were explored using the formulated FE model.展开更多
Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using...Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using a quantitative method.In this work,volumetric defect ratio was proposed as the criterion to describe the integrity of forming quality for cladding layers.Laser deposition experiments with FV520B,one of martensitic stainless steels,were designed by using the Taguchi method.Four process variables,namely,laser power(P),scanning speed(Vs),wire feed rate(Vf),and wire current(/),were optimized based on the analysis of signal-to-noise(S/N)ratio.Metallurgic observation of cladding layer was conducted to compare the forming quality and to validate the analysis method.A stable and continuous process with the optimum parameter combination produced uniform microstructure with minimal defects and cracks,which resulted in a good metallurgical bonding interface.展开更多
In this study the process of cladding steel wires with aluminum is investigated experimentally. It is studied how the cladding process and the quality of products are influenced by the aluminum deformation temperature...In this study the process of cladding steel wires with aluminum is investigated experimentally. It is studied how the cladding process and the quality of products are influenced by the aluminum deformation temperature, the wheel speed, the temperature of steel wire, the wire speed and the steel wire tensile force. The relation among the process parameters above is discussed, and the effect of the aluminum deformation temperature on the coating microstructure is analyzed. This paper suggested a reasonable range of process parameters for producing aluminum cladding steel wires.展开更多
Interface micros tructures of Cu-Ni-Si/Al-MgSi clad composite wires during isothermal annealing from 623 to 773 K were investigated.The composite wires were fabricated by a drawing process.The evolution of intermetall...Interface micros tructures of Cu-Ni-Si/Al-MgSi clad composite wires during isothermal annealing from 623 to 773 K were investigated.The composite wires were fabricated by a drawing process.The evolution of intermetallic compounds(IMCs)was analyzed.A continuous IMCs layer forms only after annealing for 1 min,which may be due to more IMCs nucleation points generated by deep drawing process.IMCs consist of Al_(4)Cu_(9),AlCu and Al_(2)Cu identified by energy-dispersive spectroscopy(EDS)and transmission electron microscopy(TEM).The growth activation energies of total IMCs,Al_(2)Cu,AlCu and Al_(4)Cu_(9),are 98.8,69.4,101.3 and 137.1 kJ·mol^(-1),respectively.The higher growth activation energy of Al_(4)Cu_(9)results in the higher growth rate under high temperature.However,the average interdiffusion coefficient for each IMC calculated by Wagner method shows that interdiffusion in Al_(2)Cu and AlCu is more active than that in Al_(4)Cu_(9).The higher growth rate of Al_(4)Cu_(9)may be caused by the long concentration range.展开更多
The force feed lubrication method is used for drawing aluminum clad steel wire. It is studied how deformation of wire and aspect of the lubricant film are influenced by the die angle, the reduction, the drawing spee...The force feed lubrication method is used for drawing aluminum clad steel wire. It is studied how deformation of wire and aspect of the lubricant film are influenced by the die angle, the reduction, the drawing speed and the gap between pressure die and wire. It has been concluded that when the factors above mentioned promote to thicken lubricant film, the drawing force is reduced and this favors the homogenous deformation of aluminum coating and steel core.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.61903268)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20190823)China Postdoctoral Science Foundation Grant(Grant No.2019M661921).
文摘Three-beam laser internal coaxial wire feeding cladding is regarded as a promising additive manufacturing technique because it is highly efficient and controllable.In this study,the effects of the defocus distance on cladding using a three-beam laser with internal wire feeding are experimentally and numerically studied.A process map indicating the surface characteristics at different defocus distances with various parameter combinations was developed.The transmission characteristics including laser intensity,beam size,and laser spot distance of the three-beam laser at different defocus distances were analyzed using TracePro software.Based on the TracePro results as heat source,a three-dimensional transient finite element(FE)thermal model was formulated to predict the thermal field,temperature history and molten pool shape at different defocus distances.A molten pool with a flat bottom and low melting depth is generated when the defocus distance is−2.5 mm,whereas when this distance is−1.5 mm,a pool with a valley-shaped bond and high melting depth is formed.The simulated results of the temperature cycle and clad geometry are both validated and found to well agree with experimental measurements.The influence of the defocus distance on the microstructure and microhardness are discussed based on the temperature history and cooling rate.With the increase in the absolute defocus distance,the height and dilution of the clad decreased,whereas the width increased.In addition,the effects of defocus distance with various parameter combinations on clad geometry were explored using the formulated FE model.
基金This work was financially supported by the National Basic Research Program of China(97 Program)(Grant No.2011CB013404).
文摘Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using a quantitative method.In this work,volumetric defect ratio was proposed as the criterion to describe the integrity of forming quality for cladding layers.Laser deposition experiments with FV520B,one of martensitic stainless steels,were designed by using the Taguchi method.Four process variables,namely,laser power(P),scanning speed(Vs),wire feed rate(Vf),and wire current(/),were optimized based on the analysis of signal-to-noise(S/N)ratio.Metallurgic observation of cladding layer was conducted to compare the forming quality and to validate the analysis method.A stable and continuous process with the optimum parameter combination produced uniform microstructure with minimal defects and cracks,which resulted in a good metallurgical bonding interface.
文摘In this study the process of cladding steel wires with aluminum is investigated experimentally. It is studied how the cladding process and the quality of products are influenced by the aluminum deformation temperature, the wheel speed, the temperature of steel wire, the wire speed and the steel wire tensile force. The relation among the process parameters above is discussed, and the effect of the aluminum deformation temperature on the coating microstructure is analyzed. This paper suggested a reasonable range of process parameters for producing aluminum cladding steel wires.
基金the National Key Research and Development Plan(No.2016YFB0301405)。
文摘Interface micros tructures of Cu-Ni-Si/Al-MgSi clad composite wires during isothermal annealing from 623 to 773 K were investigated.The composite wires were fabricated by a drawing process.The evolution of intermetallic compounds(IMCs)was analyzed.A continuous IMCs layer forms only after annealing for 1 min,which may be due to more IMCs nucleation points generated by deep drawing process.IMCs consist of Al_(4)Cu_(9),AlCu and Al_(2)Cu identified by energy-dispersive spectroscopy(EDS)and transmission electron microscopy(TEM).The growth activation energies of total IMCs,Al_(2)Cu,AlCu and Al_(4)Cu_(9),are 98.8,69.4,101.3 and 137.1 kJ·mol^(-1),respectively.The higher growth activation energy of Al_(4)Cu_(9)results in the higher growth rate under high temperature.However,the average interdiffusion coefficient for each IMC calculated by Wagner method shows that interdiffusion in Al_(2)Cu and AlCu is more active than that in Al_(4)Cu_(9).The higher growth rate of Al_(4)Cu_(9)may be caused by the long concentration range.
文摘The force feed lubrication method is used for drawing aluminum clad steel wire. It is studied how deformation of wire and aspect of the lubricant film are influenced by the die angle, the reduction, the drawing speed and the gap between pressure die and wire. It has been concluded that when the factors above mentioned promote to thicken lubricant film, the drawing force is reduced and this favors the homogenous deformation of aluminum coating and steel core.
