The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical m...The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical model height.The Taguchi method was employed to establish the correlations between process parameter combinations and multi-objective characterization of metal deposition morphology(height error and roughness).Results show that using the signal-to-noise ratio and grey relational analysis,the optimal parameter combination for multi-layer and multi-pass deposition is determined as follows:laser power of 800 W,powder feeding rate of 0.3 r/min,step distance of 1.6 mm,and scanning speed of 20 mm/s.Subsequently,a Genetic Bayesian-back propagation(GB-BP)network is constructed to predict multi-objective responses.Compared with the traditional back propagation network,the GB-back propagation network improves the prediction accuracy of height error and surface roughness by 43.14%and 71.43%,respectively.This network can accurately predict the multi-objective characterization of morphological quality of multi-layer and multi-pass metal deposited parts.展开更多
由于单晶硅的硬脆特性,常规单点金刚石车削(Single Point Diamond Turning,SPDT)加工极易发生脆性断裂和刀具磨损现象。本文基于有限元仿真分析方法和正交实验法,研究了高斯三维模型下激光参数对单晶硅温度场的影响和温度场模型下激光...由于单晶硅的硬脆特性,常规单点金刚石车削(Single Point Diamond Turning,SPDT)加工极易发生脆性断裂和刀具磨损现象。本文基于有限元仿真分析方法和正交实验法,研究了高斯三维模型下激光参数对单晶硅温度场的影响和温度场模型下激光辅助车削的优越性。研究结果表明:主轴转速、进给量、背吃刀量和激光功率对单晶硅表面粗糙度Ra的影响权重分别为17.23%、33.53%、10.60%和7.43%;最优加工工艺参数为:主轴转速4000 r/min、进给量2 mm/min、背吃刀量5μm、激光功率3 W;最终实验验证结果为,与常规加工工艺相比,采用激光辅助工艺参数,产品合格率增长了66.7%,零件表面粗糙度改善了13.3%,验证了激光辅助的优越性与原理的可靠性。展开更多
Three-beam wire-feed laser cladding,which generates a uniform energy distribution with a wire vertically fed into the molten pool,is a promising additive manufacturing technology.In this study,an experimental investig...Three-beam wire-feed laser cladding,which generates a uniform energy distribution with a wire vertically fed into the molten pool,is a promising additive manufacturing technology.In this study,an experimental investigation and a statistical analysis of Ti-6Al-4V wire cladding using three-beam laser coaxial wire-feed cladding technology coupled with a 2 kW continuous fiber laser were carried out.The influences of the main parameters,including the laser power,wire feeding speed,and laser scanning speed,on the cladding geometry and process were investigated.The prediction models correlating the process parameters and clad geometry were developed via the response surface methodology(RSM).The models were checked using analysis of variance(ANOVA).Through optimization,the optimal parameters were achieved for the required clad with a width-to-height ratio of 5:1.A high-speed camera was used to investigate the cladding process under various process parameters.The laser power positively affected the widths of the molten pool and cladding layer.The molten pool and clad heights decreased with increases in laser power and scanning speed.Fine acicular martensite grains in the colony and basket-weave distributions were predominant in the cross-section of the cladding layer.The macrostructure investigation showed that the widths of columnar prior-βgrains decreased with the increase in laser scanning speed.展开更多
基金National Natural Science Foundation of China(52175237)。
文摘The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical model height.The Taguchi method was employed to establish the correlations between process parameter combinations and multi-objective characterization of metal deposition morphology(height error and roughness).Results show that using the signal-to-noise ratio and grey relational analysis,the optimal parameter combination for multi-layer and multi-pass deposition is determined as follows:laser power of 800 W,powder feeding rate of 0.3 r/min,step distance of 1.6 mm,and scanning speed of 20 mm/s.Subsequently,a Genetic Bayesian-back propagation(GB-BP)network is constructed to predict multi-objective responses.Compared with the traditional back propagation network,the GB-back propagation network improves the prediction accuracy of height error and surface roughness by 43.14%and 71.43%,respectively.This network can accurately predict the multi-objective characterization of morphological quality of multi-layer and multi-pass metal deposited parts.
基金Supported by the National Natural Science Foundation of China(Grant Nos.62173239,61903268)Suzhou Vocational Institute of Industrial Technology Foundation(Grant Nos.2024kyqd003,2021kyqd005 and 2022kypy09).
文摘Three-beam wire-feed laser cladding,which generates a uniform energy distribution with a wire vertically fed into the molten pool,is a promising additive manufacturing technology.In this study,an experimental investigation and a statistical analysis of Ti-6Al-4V wire cladding using three-beam laser coaxial wire-feed cladding technology coupled with a 2 kW continuous fiber laser were carried out.The influences of the main parameters,including the laser power,wire feeding speed,and laser scanning speed,on the cladding geometry and process were investigated.The prediction models correlating the process parameters and clad geometry were developed via the response surface methodology(RSM).The models were checked using analysis of variance(ANOVA).Through optimization,the optimal parameters were achieved for the required clad with a width-to-height ratio of 5:1.A high-speed camera was used to investigate the cladding process under various process parameters.The laser power positively affected the widths of the molten pool and cladding layer.The molten pool and clad heights decreased with increases in laser power and scanning speed.Fine acicular martensite grains in the colony and basket-weave distributions were predominant in the cross-section of the cladding layer.The macrostructure investigation showed that the widths of columnar prior-βgrains decreased with the increase in laser scanning speed.
