Single-crystal superalloys are typical advanced materials used for manufacturing aero- engine turbine blades. Their unique characteristics of high hardness and strength make them exceedingly difficult to machine. Howe...Single-crystal superalloys are typical advanced materials used for manufacturing aero- engine turbine blades. Their unique characteristics of high hardness and strength make them exceedingly difficult to machine. However, a key structure of a turbine blade, the film-cooling hole, needs to be machined in a single-crystal superalloy; such machining is challenging, especially considering the increasing levels of machining efficiency and quality demanded by the aeroengine industry. Tube electrode high-speed electrochemical discharge drilling （TSECDD）, a hybrid technique of high-speed electrical discharge drilling and electrochemical machining, provides high machining efficiency and accuracy, as well as eliminating the recast layer. In this study, TSECDD is used to machine a film-cooling hole in a nickel-based single-crystal superalloy （DD6）. The Tagu- chi methods of experiment are used to optimise the machining parameters. Experimental results show that TSECDD can effectively drill the film-cooling hole; the optimum parameters that give the best performance are as follows： pulse duration： 12μs, pulse interval： 30 gs, peak current： 6 A, and salt solution conductivity： 3 mS/cm. Finally, a hole is machined by TSECDD, and the results are compared with those obtained by electrical discharge machining. TSECDD is found to be promising for improving the surface quality and eliminating the recast layer.展开更多
Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of ...Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of process parameters such as tool rotational speed, traverse speed and axial force on tensile strength of friction stir welded RDE-40 aluminium alloy, Taguchi parametric design and optimization approach was used. Through the Taguchi parametric design approach, the optimum levels of process parameters were determined. The results indicate that the rotational speed, welding speed and axial force are the significant parameters in deciding the tensile strength of the joint. The predicted optimal value of tensile strength of friction stir welded RDE-40 aluminium alloy is 303 MPa. The results were confirmed by further experiments.展开更多
Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and op...Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and optimized at different parameters like sliding speed, applied load, sliding time, and percentage of reinforcement by Taguchi method. The specimens were examined by Rockwell hardness test machine, Pin on Disc, Scanning Electron Microscope (SEM) and Optical Microscope. A plan of experiment generated through Taguchi’s technique is used to conduct experiments based on L27 orthogonal array. The developed ANOVA and the regression equations were used to find the optimum wear as well as co-efficient of friction under the influence of sliding speed, applied load, sliding time and percentage of reinforcement. The dry sliding wear resistance was analyzed on the basis of “smaller the best”. Finally, confirmation tests were carried out to verify the experimental results.展开更多
Zinc-aluminum alloys have been used as bearing materials in the past. In recent years, binary Al-Zn alloys and Al-Zn-Cu alloys are being used as an alternative to the Zn-Al alloys for bearing applications. In this stu...Zinc-aluminum alloys have been used as bearing materials in the past. In recent years, binary Al-Zn alloys and Al-Zn-Cu alloys are being used as an alternative to the Zn-Al alloys for bearing applications. In this study, both binary Al-25 Zn and Al-3 Cu were prepared using stir casting process. Homogenization of the as-cast alloys was performed at 350oC for 8 h and then, the alloys were furnace-cooled to 50oC. The homogenization led to the removal of the dendritic structure of the as-cast alloys. After homogenization, wear parameters optimization was carried out using Taguchi technique. For this purpose, L9 orthogonal array was selected, and the control parameters selected are load, velocity, and sliding distance. The optimum parametric condition was obtained using signal-to-noise(S/N) ratio analysis, and specific wear rate(SWR) is the selected response. The "smaller-the-better" is the goal of the experiment for S/N ratio analysis. After the optimization, confirmation tests were carried out using analysis of variance(ANOVA) from the developed regression equation. Finally, wear mechanism studies were conducted using scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDX) images.展开更多
The paper focuses on biodiesel production from kusum oil using esterification reaction followed by transesterification reaction in an in-house batch reactor setup. The effects of methanol to oil ratio (M/O), catalyst ...The paper focuses on biodiesel production from kusum oil using esterification reaction followed by transesterification reaction in an in-house batch reactor setup. The effects of methanol to oil ratio (M/O), catalyst amount (H2SO4 and methodoxide) and reaction temperature on acid value and fatty acid methyl esters (FAME) is studied. Product has been analysed using FTIR spectroscopy technique for confirmation of ester group in biodiesel. Experimental data was optimized by Taguchi analysis to conclude the optimum variable affecting the response. In both processes M/O ratio has the significant effect for biodiesel production. The obtained biodiesel properties are close to commercial diesel fuel and may be rated as an alternative to conventional diesel. The biodiesel production will enhance the maximum utilisation of forestry or agricultural products.展开更多
Taguchi methods have proved to be successful over the last two decades for improvement of product quality and process performance. This study is carried out to simultaneously optimize the tribological properties: wear...Taguchi methods have proved to be successful over the last two decades for improvement of product quality and process performance. This study is carried out to simultaneously optimize the tribological properties: wear rate and frictional force of aluminum metal matrix composite. Al-Cu-Mg alloy reinforced with 6 Wt % of titanium dioxide was prepared using stir casting method. Dry sliding wear test was conducted to understand the tribological behavior of samples. The experiments were conducted as per the Taguchi design of experiment. The wear parameters chosen for the experiment were: sliding speed and load and sliding distance. Each parameter was assigned three levels. The experiment consists of 27 tests according to L27 orthogonal array. Signal to noise ratio analysis has been carried out to determine optimal parametric condition, which yields minimum wear rate and frictional force. Harrington’s desirability functional method is adopted for multifunctional optimization of tribological parameters and the confirmation experiments were conducted to verify the predicted model.展开更多
In this current work,aluminum alloy grade 2024 is adopted as a plate material that is used in the rolling process with three different parameters including thickness reduction,forming temperature,and density of lubric...In this current work,aluminum alloy grade 2024 is adopted as a plate material that is used in the rolling process with three different parameters including thickness reduction,forming temperature,and density of lubrication type.The experimental procedure of the rolling process is performed using the design of the experiment based on the Taguchi technique(L27),then surface roughness,surface hardness,and surface residual stresses are measured.The results showed that the lubrication density has a significant impact on the surface roughness which depends on the lubrication properties(mineral oil type,natural fat,and kinematic viscosity)while surface hardness and surface residual stresses were strongly affected by thickness reduction.On the other side,the augment in forming temperature can decrease the quality of the final surface finish and the surface hardness but reduce the induced residual stresses.The best surface finish is obtained based on the optimum condition of the rolling factors are(R%_(3),T_(1),andρ_(3))while the optimum condition of rolling parameters that generate higher hardness and compressive residual stresses are(R%_(3)T_(1)ρ_(1)).展开更多
In this research study,the mechanical properties of several Polymer matrix composites are investigated.These composites are multi-phase materials in which reinforcing materials are properly mixed with a polymer matrix...In this research study,the mechanical properties of several Polymer matrix composites are investigated.These composites are multi-phase materials in which reinforcing materials are properly mixed with a polymer matrix.More precisely,Nylon 6 reinforced with 5,15 and 25 wt.%of silicon carbide(SiC)and Nylon 6 reinforced with 5,15 and 25 wt.%of boron carbide(B_(4)C),prepared by means of an injection moulding process at three different injection pressures are considered.Specific attention is paid to the tensile and impact strength of these composites.The Taguchi technique is used to optimize the process parameters such as reinforcement material,its percentage and the injection pressure.It is observed that the specimens 5%SiC with 80 MPa injection pressure display a better tensile strength and similarly the specimen 5%B_(4)C with 90 MPa injection pressure have a superior impact strength.展开更多
收缩、沉降斑和残余应力是衡量注塑制品性能和表面质量的重要指标。将CAE与DOE(design of experiment)技术相结合,可在较少的分析次数下获得优化工艺,从而改善制品质量。文中基于一个工业产品,在L9(34)正交试验设计与Moldflow模拟分析...收缩、沉降斑和残余应力是衡量注塑制品性能和表面质量的重要指标。将CAE与DOE(design of experiment)技术相结合,可在较少的分析次数下获得优化工艺,从而改善制品质量。文中基于一个工业产品,在L9(34)正交试验设计与Moldflow模拟分析的基础上,研究工艺参数对注塑制品体积收缩率变化、沉降斑指数和残余应力的影响,获得优化工艺参数,使体积收缩率变化、沉降斑指数和残余应力达到最小。展开更多
基金financial support provided by the National Natural Science Foundation of China(No.51475237)the National High-Tech Research and Development Program of China(2013AA040101)+1 种基金the Program for New Century Excellent Talents in University of China(No.NCET-12-0627)the Funding of Jiangsu Innovation Program for Graduate Education of China(No.KYLX_0232)
文摘Single-crystal superalloys are typical advanced materials used for manufacturing aero- engine turbine blades. Their unique characteristics of high hardness and strength make them exceedingly difficult to machine. However, a key structure of a turbine blade, the film-cooling hole, needs to be machined in a single-crystal superalloy; such machining is challenging, especially considering the increasing levels of machining efficiency and quality demanded by the aeroengine industry. Tube electrode high-speed electrochemical discharge drilling （TSECDD）, a hybrid technique of high-speed electrical discharge drilling and electrochemical machining, provides high machining efficiency and accuracy, as well as eliminating the recast layer. In this study, TSECDD is used to machine a film-cooling hole in a nickel-based single-crystal superalloy （DD6）. The Tagu- chi methods of experiment are used to optimise the machining parameters. Experimental results show that TSECDD can effectively drill the film-cooling hole; the optimum parameters that give the best performance are as follows： pulse duration： 12μs, pulse interval： 30 gs, peak current： 6 A, and salt solution conductivity： 3 mS/cm. Finally, a hole is machined by TSECDD, and the results are compared with those obtained by electrical discharge machining. TSECDD is found to be promising for improving the surface quality and eliminating the recast layer.
文摘Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of process parameters such as tool rotational speed, traverse speed and axial force on tensile strength of friction stir welded RDE-40 aluminium alloy, Taguchi parametric design and optimization approach was used. Through the Taguchi parametric design approach, the optimum levels of process parameters were determined. The results indicate that the rotational speed, welding speed and axial force are the significant parameters in deciding the tensile strength of the joint. The predicted optimal value of tensile strength of friction stir welded RDE-40 aluminium alloy is 303 MPa. The results were confirmed by further experiments.
文摘Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and optimized at different parameters like sliding speed, applied load, sliding time, and percentage of reinforcement by Taguchi method. The specimens were examined by Rockwell hardness test machine, Pin on Disc, Scanning Electron Microscope (SEM) and Optical Microscope. A plan of experiment generated through Taguchi’s technique is used to conduct experiments based on L27 orthogonal array. The developed ANOVA and the regression equations were used to find the optimum wear as well as co-efficient of friction under the influence of sliding speed, applied load, sliding time and percentage of reinforcement. The dry sliding wear resistance was analyzed on the basis of “smaller the best”. Finally, confirmation tests were carried out to verify the experimental results.
文摘Zinc-aluminum alloys have been used as bearing materials in the past. In recent years, binary Al-Zn alloys and Al-Zn-Cu alloys are being used as an alternative to the Zn-Al alloys for bearing applications. In this study, both binary Al-25 Zn and Al-3 Cu were prepared using stir casting process. Homogenization of the as-cast alloys was performed at 350oC for 8 h and then, the alloys were furnace-cooled to 50oC. The homogenization led to the removal of the dendritic structure of the as-cast alloys. After homogenization, wear parameters optimization was carried out using Taguchi technique. For this purpose, L9 orthogonal array was selected, and the control parameters selected are load, velocity, and sliding distance. The optimum parametric condition was obtained using signal-to-noise(S/N) ratio analysis, and specific wear rate(SWR) is the selected response. The "smaller-the-better" is the goal of the experiment for S/N ratio analysis. After the optimization, confirmation tests were carried out using analysis of variance(ANOVA) from the developed regression equation. Finally, wear mechanism studies were conducted using scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDX) images.
文摘The paper focuses on biodiesel production from kusum oil using esterification reaction followed by transesterification reaction in an in-house batch reactor setup. The effects of methanol to oil ratio (M/O), catalyst amount (H2SO4 and methodoxide) and reaction temperature on acid value and fatty acid methyl esters (FAME) is studied. Product has been analysed using FTIR spectroscopy technique for confirmation of ester group in biodiesel. Experimental data was optimized by Taguchi analysis to conclude the optimum variable affecting the response. In both processes M/O ratio has the significant effect for biodiesel production. The obtained biodiesel properties are close to commercial diesel fuel and may be rated as an alternative to conventional diesel. The biodiesel production will enhance the maximum utilisation of forestry or agricultural products.
文摘Taguchi methods have proved to be successful over the last two decades for improvement of product quality and process performance. This study is carried out to simultaneously optimize the tribological properties: wear rate and frictional force of aluminum metal matrix composite. Al-Cu-Mg alloy reinforced with 6 Wt % of titanium dioxide was prepared using stir casting method. Dry sliding wear test was conducted to understand the tribological behavior of samples. The experiments were conducted as per the Taguchi design of experiment. The wear parameters chosen for the experiment were: sliding speed and load and sliding distance. Each parameter was assigned three levels. The experiment consists of 27 tests according to L27 orthogonal array. Signal to noise ratio analysis has been carried out to determine optimal parametric condition, which yields minimum wear rate and frictional force. Harrington’s desirability functional method is adopted for multifunctional optimization of tribological parameters and the confirmation experiments were conducted to verify the predicted model.
文摘In this current work,aluminum alloy grade 2024 is adopted as a plate material that is used in the rolling process with three different parameters including thickness reduction,forming temperature,and density of lubrication type.The experimental procedure of the rolling process is performed using the design of the experiment based on the Taguchi technique(L27),then surface roughness,surface hardness,and surface residual stresses are measured.The results showed that the lubrication density has a significant impact on the surface roughness which depends on the lubrication properties(mineral oil type,natural fat,and kinematic viscosity)while surface hardness and surface residual stresses were strongly affected by thickness reduction.On the other side,the augment in forming temperature can decrease the quality of the final surface finish and the surface hardness but reduce the induced residual stresses.The best surface finish is obtained based on the optimum condition of the rolling factors are(R%_(3),T_(1),andρ_(3))while the optimum condition of rolling parameters that generate higher hardness and compressive residual stresses are(R%_(3)T_(1)ρ_(1)).
文摘In this research study,the mechanical properties of several Polymer matrix composites are investigated.These composites are multi-phase materials in which reinforcing materials are properly mixed with a polymer matrix.More precisely,Nylon 6 reinforced with 5,15 and 25 wt.%of silicon carbide(SiC)and Nylon 6 reinforced with 5,15 and 25 wt.%of boron carbide(B_(4)C),prepared by means of an injection moulding process at three different injection pressures are considered.Specific attention is paid to the tensile and impact strength of these composites.The Taguchi technique is used to optimize the process parameters such as reinforcement material,its percentage and the injection pressure.It is observed that the specimens 5%SiC with 80 MPa injection pressure display a better tensile strength and similarly the specimen 5%B_(4)C with 90 MPa injection pressure have a superior impact strength.
文摘收缩、沉降斑和残余应力是衡量注塑制品性能和表面质量的重要指标。将CAE与DOE(design of experiment)技术相结合,可在较少的分析次数下获得优化工艺,从而改善制品质量。文中基于一个工业产品,在L9(34)正交试验设计与Moldflow模拟分析的基础上,研究工艺参数对注塑制品体积收缩率变化、沉降斑指数和残余应力的影响,获得优化工艺参数,使体积收缩率变化、沉降斑指数和残余应力达到最小。
