Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.008
A. Onur
AA2011 aluminium-alloy powders were produced in an atomization unit, which was previously designed and manufactured, by using the oil as atomization fluid. Negative influence of oxide amount on the produced parts was reduced compared to water atomization method. Test specimens were produced by pressing the powders into the mold. In addition, age hardening process was applied to these specimens and comparisons were made with the parts produced by rolling process. The results showed that there was a significant difference in the hardness values depending on the time. Introduction Part production by Powder Metallurgy (PM) is commonly used and it has become an alternative to the classical processing methods. High quality powders have to be used in order to fabricate the materials by using PM method. Production of metal powders by atomisation technique has an important place in the present time. In the litereture, there are three types of powder production methods such as water, inert-gas and air atomisation [1,2,3,4,7]. Gas and water atomisation, which are also called two fluid atomisation, are generally preferred for the production of high capacity powders [5]. However, there are certain limited properties of these powders produced by gas and water atomisation methods. For example, metal powders take the oxigen from the water, and oxigen percentages in the Al, Fe, Ni, Co and Cr alloys would become more than 1000 ppm. For this reason, in case of the usage of the powders produced by the water atomisation method containing high percentage of the oxigen, the notch impact strength of the produced parts decreases [1]. However, the oxigen rate in the inert-gas atomisation is lower than that of water atomisation. On the other hand, the cost of the gas becomes an important factor if argon and helium were used as inert-gas. The oxygen percentages in the metal powders produced by certain atomisation techniques are given in Table 1. In this study, the oil atomisation method was used instead of water in order to reduce the oxide amount in the produced powders. Table 1. The oxigen amount in the 125/45 μm powders of tin and AA2011
{"title":"Application of Age Hardening Process to AA2011 Powders Produced by Oil Atomization Method","authors":"A. Onur","doi":"10.11127/IJAMMC.2013.02.008","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.008","url":null,"abstract":"AA2011 aluminium-alloy powders were produced in an atomization unit, which was previously designed and manufactured, by using the oil as atomization fluid. Negative influence of oxide amount on the produced parts was reduced compared to water atomization method. Test specimens were produced by pressing the powders into the mold. In addition, age hardening process was applied to these specimens and comparisons were made with the parts produced by rolling process. The results showed that there was a significant difference in the hardness values depending on the time. Introduction Part production by Powder Metallurgy (PM) is commonly used and it has become an alternative to the classical processing methods. High quality powders have to be used in order to fabricate the materials by using PM method. Production of metal powders by atomisation technique has an important place in the present time. In the litereture, there are three types of powder production methods such as water, inert-gas and air atomisation [1,2,3,4,7]. Gas and water atomisation, which are also called two fluid atomisation, are generally preferred for the production of high capacity powders [5]. However, there are certain limited properties of these powders produced by gas and water atomisation methods. For example, metal powders take the oxigen from the water, and oxigen percentages in the Al, Fe, Ni, Co and Cr alloys would become more than 1000 ppm. For this reason, in case of the usage of the powders produced by the water atomisation method containing high percentage of the oxigen, the notch impact strength of the produced parts decreases [1]. However, the oxigen rate in the inert-gas atomisation is lower than that of water atomisation. On the other hand, the cost of the gas becomes an important factor if argon and helium were used as inert-gas. The oxygen percentages in the metal powders produced by certain atomisation techniques are given in Table 1. In this study, the oil atomisation method was used instead of water in order to reduce the oxide amount in the produced powders. Table 1. The oxigen amount in the 125/45 μm powders of tin and AA2011","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123769325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.061
R. Rudrapati, A. Bandyopadhyay, P. K. Pal
Present work aims to study the effects of grinding parameters on surface roughness (Ra and Rq) in traverse cut cylindrical grinding process, while grinding of stainless steel. Experiments have been conducted as per L9 orthogonal array of Taguchi method. Grey based Taguchi method has been used to optimize the grinding parameters to minimize surface roughness parameters Ra and Rq simultaneously. The analysis of signal to noise ratio has been applied to investigate the effects of grinding parameters and optimize them. From the results of this study, longitudinal feed is identified as the most influential grinding parameter on surface roughness. The optimization methodology used in the present study of cylindrical grinding process is very useful to determine the optimum grinding parameters for minimum surface roughness. In the manufacturing industry, surface finish of any machined product is very important to determine the product’s quality, in so far as cylindrical jobs are concerned, it is obviously true as well. Cylindrical grinding is one of the important manufacturing processes, used for producing accurate and good surface finish cylindrical rods. Obtaining the better surface finish jobs in cylindrical grinding is mainly depends on correct selection of grinding parameters. Optimum parameter selection is difficult task in cylindrical grinding process because of its complexity while solving it. But, through systematic optimization methodology like design of experiments (DoE), it is possible to select optimum parametric combination. The present work is an attempt to optimize grinding parameters to minimize surface finish by using DoE’s Taguchi method. Good surface finish is demanded in many engineering and domestic applications, because, it is an important aspect of tolerance of finished part; it minimizes friction and wear, thereby enhancing operating hours of the components. The arithmetic average height parameter (Ra) is an important roughness parameter, which most universally accepted and used roughness parameter to describe the quality of machined part. Review of available literature shows that Ra has been focus of most of the studies, but, Ra parameter alonely can’t provide full description of surface. Root mean square roughness (Rq) is also an important parameter used to specify quality of the machined part. It is more sensitive than Ra. If the number of roughness parameters used is increased, full description of the surface profile can be obtained [1]. The present study aims at consideration of two roughness parameters Ra and Rq simultaneously for the surface roughness generated in cylindrical grinding operation. Extensive literature survey has been made on optimization of process parameters in different machining operations for single objective optimization problem using Taguchi method [2] and multi objective optimization by using Taguchi method combined with grey relation analysis [3, 4]. Some of the previous studies are included here, Ta
{"title":"Multi-Objective Optimization in Traverse Cut Cylindrical Grinding","authors":"R. Rudrapati, A. Bandyopadhyay, P. K. Pal","doi":"10.11127/IJAMMC.2013.02.061","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.061","url":null,"abstract":"Present work aims to study the effects of grinding parameters on surface roughness (Ra and Rq) in traverse cut cylindrical grinding process, while grinding of stainless steel. Experiments have been conducted as per L9 orthogonal array of Taguchi method. Grey based Taguchi method has been used to optimize the grinding parameters to minimize surface roughness parameters Ra and Rq simultaneously. The analysis of signal to noise ratio has been applied to investigate the effects of grinding parameters and optimize them. From the results of this study, longitudinal feed is identified as the most influential grinding parameter on surface roughness. The optimization methodology used in the present study of cylindrical grinding process is very useful to determine the optimum grinding parameters for minimum surface roughness. In the manufacturing industry, surface finish of any machined product is very important to determine the product’s quality, in so far as cylindrical jobs are concerned, it is obviously true as well. Cylindrical grinding is one of the important manufacturing processes, used for producing accurate and good surface finish cylindrical rods. Obtaining the better surface finish jobs in cylindrical grinding is mainly depends on correct selection of grinding parameters. Optimum parameter selection is difficult task in cylindrical grinding process because of its complexity while solving it. But, through systematic optimization methodology like design of experiments (DoE), it is possible to select optimum parametric combination. The present work is an attempt to optimize grinding parameters to minimize surface finish by using DoE’s Taguchi method. Good surface finish is demanded in many engineering and domestic applications, because, it is an important aspect of tolerance of finished part; it minimizes friction and wear, thereby enhancing operating hours of the components. The arithmetic average height parameter (Ra) is an important roughness parameter, which most universally accepted and used roughness parameter to describe the quality of machined part. Review of available literature shows that Ra has been focus of most of the studies, but, Ra parameter alonely can’t provide full description of surface. Root mean square roughness (Rq) is also an important parameter used to specify quality of the machined part. It is more sensitive than Ra. If the number of roughness parameters used is increased, full description of the surface profile can be obtained [1]. The present study aims at consideration of two roughness parameters Ra and Rq simultaneously for the surface roughness generated in cylindrical grinding operation. Extensive literature survey has been made on optimization of process parameters in different machining operations for single objective optimization problem using Taguchi method [2] and multi objective optimization by using Taguchi method combined with grey relation analysis [3, 4]. Some of the previous studies are included here, Ta","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134284061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.081
P. Rao, P. Raju, V. Sreenivasulu, P. Reddy
These major issues are putting pressure on automakers to develop new technologies to increase the fuel economy and decrease the emissions while maintaining or improving the engine’s performance. Several new technologies have resulted. All of these technologies accomplish these goals by increasing the efficiency of an engine. As a whole these technologies are called variable valve actuation. These technologies achieve a higher efficiency by reducing the constants of the engine. However, the added variability increases the time to calibrate an engine. To address this, more testing is being performed using engine simulations instead of physical testing. This thesis focuses on how to create an engine model and how engine simulation can be used to optimize such an engine. In addition the benefits of a particular variable valve actuation technology, cam phasing, will be explored A conventional engine has static, mechanically-actuated valves and a compression ratio that is fixed once the components of the engine are chosen. A recently developed technology called variable valve actuation (VVA) enables added control of valve timing, lift and/or duration. With this additional freedom, the efficiency of an engine can be greatly increased. Not only can the compression ratio be increased with the addition of VVA, but also the necessity of throttling can be reduced[1,12] Although cam phasing has numerous benefits, it also has significant drawbacks. The largest drawback is a substantial increase in the amount of testing required to create an optimized engine map. By using engine modeling, the amount of testing required is reduced because most of the testing is done virtually through a simulation. The creating of an engine model requires a broad range of experimental data. To make an accurate model, the data must span the entire range of operating conditions. However, only a relatively small amount of data is needed. This thesis focuses on how to create an engine model and how to use the model to optimize engine development. In this study the abilities of GT-Power, an engine simulation program, will specifically be explored. Both the cycle resolved and cycle averaged data will be presented. The simulations will show the effect of intake and exhaust cam phasing on the trapped air mass, the trapped residual gases, intake air temperature, indicated mean effective pressure and combustion stability.[2,24] Variable Valve Actuation In standard IC engines, the compression ratio (set by the engine’s mechanical design) is also fixed for all engine conditions. The compression rate is thus limited by the engine condition with the lowest knock limit. Engine knock is caused by spontaneous combustion of fuel without a spark (auto-ignition).For spontaneous combustion to occur, the temperature and pressure must be sufficiently high. Therefore the limiting condition occurs at wide open throttle (WOT) and engine speeds close to redline. Likewise, lower engine speeds and throttled
{"title":"Design of . Variable Valve Actuation in I.C.Engine","authors":"P. Rao, P. Raju, V. Sreenivasulu, P. Reddy","doi":"10.11127/IJAMMC.2013.02.081","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.081","url":null,"abstract":"These major issues are putting pressure on automakers to develop new technologies to increase the fuel economy and decrease the emissions while maintaining or improving the engine’s performance. Several new technologies have resulted. All of these technologies accomplish these goals by increasing the efficiency of an engine. As a whole these technologies are called variable valve actuation. These technologies achieve a higher efficiency by reducing the constants of the engine. However, the added variability increases the time to calibrate an engine. To address this, more testing is being performed using engine simulations instead of physical testing. This thesis focuses on how to create an engine model and how engine simulation can be used to optimize such an engine. In addition the benefits of a particular variable valve actuation technology, cam phasing, will be explored A conventional engine has static, mechanically-actuated valves and a compression ratio that is fixed once the components of the engine are chosen. A recently developed technology called variable valve actuation (VVA) enables added control of valve timing, lift and/or duration. With this additional freedom, the efficiency of an engine can be greatly increased. Not only can the compression ratio be increased with the addition of VVA, but also the necessity of throttling can be reduced[1,12] Although cam phasing has numerous benefits, it also has significant drawbacks. The largest drawback is a substantial increase in the amount of testing required to create an optimized engine map. By using engine modeling, the amount of testing required is reduced because most of the testing is done virtually through a simulation. The creating of an engine model requires a broad range of experimental data. To make an accurate model, the data must span the entire range of operating conditions. However, only a relatively small amount of data is needed. This thesis focuses on how to create an engine model and how to use the model to optimize engine development. In this study the abilities of GT-Power, an engine simulation program, will specifically be explored. Both the cycle resolved and cycle averaged data will be presented. The simulations will show the effect of intake and exhaust cam phasing on the trapped air mass, the trapped residual gases, intake air temperature, indicated mean effective pressure and combustion stability.[2,24] Variable Valve Actuation In standard IC engines, the compression ratio (set by the engine’s mechanical design) is also fixed for all engine conditions. The compression rate is thus limited by the engine condition with the lowest knock limit. Engine knock is caused by spontaneous combustion of fuel without a spark (auto-ignition).For spontaneous combustion to occur, the temperature and pressure must be sufficiently high. Therefore the limiting condition occurs at wide open throttle (WOT) and engine speeds close to redline. Likewise, lower engine speeds and throttled ","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132617885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.041
C. Singh, K. Mer
Particulate metal matrix composites (PMMCs) have proved their viability as good alternatives to conventional alloys in high strength and stiffness applications but they are still long away from highvolume commercial production. PMMCs are a special category of virtually isotropic composites. PMMCs contain different variety of the particles either hard or soft or their mixtures in a ductile metal or alloy matrix. Therefore, PMMCs combine metallic properties (ductility and toughness) with the characteristics of reinforcement particles, often leading to greater strength, higher wear resistance and better properties at elevated temperature depending on the nature of particles. In the recent past researchers are concentrating on the easy low cost techniques for the synthesis of PMMCs, like stir casting.In the present work cast particle reinforced composites containing in-situ generated reinforcement Alumina particles have been synthesized by solidification of slurry obtain by dispersion of externally added Manganese Dioxide (MnO2) particles in the molten aluminium. Alumina particles have been generated by the reaction of the Manganese Dioxide with molten Aluminium. The chemical reaction also releases Manganese in to molten Aluminium which increases the strength of the matrix. Magnesium is added to the melt in order to help wetting of alumina particles in molten Aluminium and to retain the particles inside the melt. The present work also investigates the abrasion wear properties of the resulting cast in-situ composites. In the present work the Aluminium alloy (Al + 5% Mg) matrix composite reinforced with Alumina particles have been synthesized in the open hearth furnace with the hand stirring method. The present work shows the effect of the reinforcement on the abrasion wear properties of casted alloy and casted composites. The present work also compares the abrasion wear properties of pure Aluminium, the casted alloy and the casted composites. Aluminium based metal matrix materials have a combination of different, superior properties to an unreinforced matrix which are; increased strength, higher elastic modulus, higher service temperature, improved wear resistance, low coefficient of thermal expansion and high vacuum environmental resistance. Axen et al. [1] have noted that, in a variety of wear conditions, the particulate reinforced composites perform better than the fibrereinforced composites. Now a day’s researchers all over the world are focusing mainly on aluminium [2] because of its unique combination of good corrosion resistance, low density and excellent mechanical properties. The unique thermal properties of aluminium composites such as metallic conductivity with coefficient of expansion that can be tailored down to zero, add to their prospects in aerospace. The matrix phase for a MMC is a metal often which is ductile. MMCs are manufactured with aims to have high strength to weight ratio, high resistance to abrasion and corrosion, resistance
{"title":"Abrasion Wear Characterization of Al-Al2O3 in-situ Particulate Composite Synthesized in Open Hearth Furnace with Manually Controlled Stirring Method","authors":"C. Singh, K. Mer","doi":"10.11127/IJAMMC.2013.02.041","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.041","url":null,"abstract":"Particulate metal matrix composites (PMMCs) have proved their viability as good alternatives to conventional alloys in high strength and stiffness applications but they are still long away from highvolume commercial production. PMMCs are a special category of virtually isotropic composites. PMMCs contain different variety of the particles either hard or soft or their mixtures in a ductile metal or alloy matrix. Therefore, PMMCs combine metallic properties (ductility and toughness) with the characteristics of reinforcement particles, often leading to greater strength, higher wear resistance and better properties at elevated temperature depending on the nature of particles. In the recent past researchers are concentrating on the easy low cost techniques for the synthesis of PMMCs, like stir casting.In the present work cast particle reinforced composites containing in-situ generated reinforcement Alumina particles have been synthesized by solidification of slurry obtain by dispersion of externally added Manganese Dioxide (MnO2) particles in the molten aluminium. Alumina particles have been generated by the reaction of the Manganese Dioxide with molten Aluminium. The chemical reaction also releases Manganese in to molten Aluminium which increases the strength of the matrix. Magnesium is added to the melt in order to help wetting of alumina particles in molten Aluminium and to retain the particles inside the melt. The present work also investigates the abrasion wear properties of the resulting cast in-situ composites. In the present work the Aluminium alloy (Al + 5% Mg) matrix composite reinforced with Alumina particles have been synthesized in the open hearth furnace with the hand stirring method. The present work shows the effect of the reinforcement on the abrasion wear properties of casted alloy and casted composites. The present work also compares the abrasion wear properties of pure Aluminium, the casted alloy and the casted composites. Aluminium based metal matrix materials have a combination of different, superior properties to an unreinforced matrix which are; increased strength, higher elastic modulus, higher service temperature, improved wear resistance, low coefficient of thermal expansion and high vacuum environmental resistance. Axen et al. [1] have noted that, in a variety of wear conditions, the particulate reinforced composites perform better than the fibrereinforced composites. Now a day’s researchers all over the world are focusing mainly on aluminium [2] because of its unique combination of good corrosion resistance, low density and excellent mechanical properties. The unique thermal properties of aluminium composites such as metallic conductivity with coefficient of expansion that can be tailored down to zero, add to their prospects in aerospace. The matrix phase for a MMC is a metal often which is ductile. MMCs are manufactured with aims to have high strength to weight ratio, high resistance to abrasion and corrosion, resistance ","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134422171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.005
C. Vidal, V. Infante, P. Peças, P. Vilaça
The Friction Stir Welding (FSW) process is still an innovative solid state mechanical processing technology enabling high quality joints in materials previously considered with low weldability such as most of the aeronautic aluminium alloys. The Taguchi method was used to find the optimal FSW parameters for improvement mechanical behaviour of AA2024-T351. The Taguchi design is an efficient and effective experimental method in which a response variable can be optimized. The parameters considered were vertical downward forging force, travel speed and pin length. An orthogonal array of L9 (34) was used; ANOVA analyses were carried out to identify the significant factors affecting tensile strength (GETS), bending toughness (GEB) and hardness field. An algebraic model for predicting the best mechanical performance was developed and the optimal FSW combination was determined using this model. The results obtained were validated by conducting confirmation experiments. Significant interest has been shown in the use of advanced welding techniques for aircraft structures, particularly given the design and manufacturing benefits they afford over established mechanical joining methods. Whilst a variety of welding methods have been identified for airframe structures, friction stir welding is an important candidate technique that is distinctive in being a low energy, solid-state process [1]. Although the friction stir welding joints have a better quality compared to the fusion techniques, there are still some defects that may arise and which are very sensitive to small variations in process parameters. Typical defects that may arise in FSW joints result from: imperfect stir of the materials during the processing, inadequate surface preparation, lack of penetration of the pin and non-uniform vertical forging forces along the material thickness. Some characteristic FSW defects are lack of penetration (typically addressed as kissing-bond), root flaw (concerning weak or intermittent linking), voids on the advancing side and second phased particles and oxides alignment under the shoulder [2]. Advanced aerospace aluminium alloys have been required to allow high fracture toughness, higher fatigue performance, high formability, and superplasticity to meet the needs for lower structural weight, higher damage tolerance and durability [3].
{"title":"Application of Taguchi Method in the Optimization of Friction Stir Welding Parameters of an Aeronautic Aluminium Alloy","authors":"C. Vidal, V. Infante, P. Peças, P. Vilaça","doi":"10.11127/IJAMMC.2013.02.005","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.005","url":null,"abstract":"The Friction Stir Welding (FSW) process is still an innovative solid state mechanical processing technology enabling high quality joints in materials previously considered with low weldability such as most of the aeronautic aluminium alloys. The Taguchi method was used to find the optimal FSW parameters for improvement mechanical behaviour of AA2024-T351. The Taguchi design is an efficient and effective experimental method in which a response variable can be optimized. The parameters considered were vertical downward forging force, travel speed and pin length. An orthogonal array of L9 (34) was used; ANOVA analyses were carried out to identify the significant factors affecting tensile strength (GETS), bending toughness (GEB) and hardness field. An algebraic model for predicting the best mechanical performance was developed and the optimal FSW combination was determined using this model. The results obtained were validated by conducting confirmation experiments. Significant interest has been shown in the use of advanced welding techniques for aircraft structures, particularly given the design and manufacturing benefits they afford over established mechanical joining methods. Whilst a variety of welding methods have been identified for airframe structures, friction stir welding is an important candidate technique that is distinctive in being a low energy, solid-state process [1]. Although the friction stir welding joints have a better quality compared to the fusion techniques, there are still some defects that may arise and which are very sensitive to small variations in process parameters. Typical defects that may arise in FSW joints result from: imperfect stir of the materials during the processing, inadequate surface preparation, lack of penetration of the pin and non-uniform vertical forging forces along the material thickness. Some characteristic FSW defects are lack of penetration (typically addressed as kissing-bond), root flaw (concerning weak or intermittent linking), voids on the advancing side and second phased particles and oxides alignment under the shoulder [2]. Advanced aerospace aluminium alloys have been required to allow high fracture toughness, higher fatigue performance, high formability, and superplasticity to meet the needs for lower structural weight, higher damage tolerance and durability [3].","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"28 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133051552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.009
N. Kavak
A B S T R A C T The objective of this study is to investigate the capability of adhesive with adding aluminium powder and 63/37 Sn-Pb soft solder powder and copper powder to the epoxy to increase the mechanical strength of joints. The adhesive strength of the joints was determined by utilizing the single-lap shear test. Experimental results show that joints prepared by adhesive which was modified, adding 5 wt% 63/37 Sn-Pb powder have more mechanical strength than joints compared to ones which were prepared by adding aluminium powder and copper powder with ratio as 5 wt%.
{"title":"Investigation of Effect to Mechanical Strength of Additive Powder Type into Adhesive","authors":"N. Kavak","doi":"10.11127/IJAMMC.2013.02.009","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.009","url":null,"abstract":"A B S T R A C T The objective of this study is to investigate the capability of adhesive with adding aluminium powder and 63/37 Sn-Pb soft solder powder and copper powder to the epoxy to increase the mechanical strength of joints. The adhesive strength of the joints was determined by utilizing the single-lap shear test. Experimental results show that joints prepared by adhesive which was modified, adding 5 wt% 63/37 Sn-Pb powder have more mechanical strength than joints compared to ones which were prepared by adding aluminium powder and copper powder with ratio as 5 wt%.","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122178055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.025
N. Krishnamurthy, Y. Singh, A. Gupta, Swadesh Kumar Singh
The main focus of this paper is prediction of flow stress of Austenitic Stainless Steel 304 in the Dynamic Strain Aging (DSA) regime. For this purpose, a comparative study has been made on the capability of modified Zerilli Armstrong (ZA) model and the Artificial Neural Networks (ANN) model for representing the flow stress prediction in the DSA Regime. The DSA regime was identified by observing the serrations in the plot between true stress and true strain.The modified-ZA equation for prediction of flow behavior at elevated temperature of the material considers isotropic hardening, temperature softening, strain rate hardening, and the coupled effects of temperature and strain and of strain rate and temperature on the flow stress. Artificial Neural Network is another powerful tool to predict the flow stress behavior which uses a part of the data to train the network while the other is used to validate the model. Suitability of these models was evaluated by comparing the correlation coefficient and absolute average error of prediction. It was observed that the flow stress predictions of ZA model were not as accurate as compared to predictions of ANN model. The resultant value of the correlation coefficient for ZA Model was 0.8889 and that of ANN’s tested data was 0.9990.
{"title":"Prediction of Deformation Behavior of Austenitic Stainless Steel 304 in Dynamic Strain Aging Regime","authors":"N. Krishnamurthy, Y. Singh, A. Gupta, Swadesh Kumar Singh","doi":"10.11127/IJAMMC.2013.02.025","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.025","url":null,"abstract":"The main focus of this paper is prediction of flow stress of Austenitic Stainless Steel 304 in the Dynamic Strain Aging (DSA) regime. For this purpose, a comparative study has been made on the capability of modified Zerilli Armstrong (ZA) model and the Artificial Neural Networks (ANN) model for representing the flow stress prediction in the DSA Regime. The DSA regime was identified by observing the serrations in the plot between true stress and true strain.The modified-ZA equation for prediction of flow behavior at elevated temperature of the material considers isotropic hardening, temperature softening, strain rate hardening, and the coupled effects of temperature and strain and of strain rate and temperature on the flow stress. Artificial Neural Network is another powerful tool to predict the flow stress behavior which uses a part of the data to train the network while the other is used to validate the model. Suitability of these models was evaluated by comparing the correlation coefficient and absolute average error of prediction. It was observed that the flow stress predictions of ZA model were not as accurate as compared to predictions of ANN model. The resultant value of the correlation coefficient for ZA Model was 0.8889 and that of ANN’s tested data was 0.9990.","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125843348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.055
R. Ramesh, N. Murugan
Friction stir processing (FSP) is an emerging novel, green and energy efficient processing technique to fabricate surface composites which is based on the basic principles of friction stir welding. The distinct advantages of friction stir processing are microstructural refinement, densification, homogeneity, accurate control and variable depth of the processed zone. Metal matrix composites, particularly Aluminium based metal matrix composites, reinforced with ceramics were developed as an alternative to materials with superior strength to weight ratio and strength to cost ratio, high stiffness, and thermal stability, which effect on improving wear, creep and fatigue resistance. However, these composites also suffer from low ductility and toughness due to the incorporation of ceramic reinforcements. For many applications, a combination of high surface wear resistance and high toughness of the interior bulk material required. In those situations, it is desirable that only the surface layer of components is reinforced with ceramic particles while the bulk retains the original composition and structure with higher toughness. In this paper, the details about the fabrication of Al 7075-T651 B4C surface composite by FSP to have improved surface hardness are provided. A tool made of high carbon high chromium steel and hardened to 62 HRC, having cylindrical profile was used for FSP. By using SYSTAT software regression model has been developed for predicting microhardness of processed surface composite. The fabricated surface composites were examined using optical microscope and found defect free friction stir processed zone. It was also observed that Boron Carbide particles were uniformly distributed and well bonded with the matrix alloy fabricated at high heat input condition. It was found that the average hardness of friction stir processed surface composite was 1.5 times higher than that of the base metal aluminium 7075 – T651. The increase in hardness was attributed to fine dispersion of B4C particles and fine grain size of the aluminium matrix. Friction Stir Processing [1] is a new, solid state processing technique for microstructural modifications, which was developed based on the principle of friction-stir welding (FSW). A non-consumable rotating tool with a pin and shoulder is inserted into the material and travelled along the desired path. Because of this the frictional heat is generated and the material undergoes severe plastic deformation, resulting in significant microstructural modification in the processed zone. FSP creates a region called the Nugget or Stir zone, where the refinement of microstructure takes place producing equiaxed fine grains with high grain boundaries. Figure 1 shows the step by step procedure of Friction Stir Processing. Fig.1 Friction Stir Processing (a) Rotating tool prior to contact with the plate; (b) Tool pin contacts plate creating heat; (c) Shoulder of tool contacts plate restricting further penetration while expa
{"title":"Microstructure and Metallurgical Properties of Aluminium 7075 – T651 Alloy / B4c 4 % Vol. Surface Composite by Friction Stir Processing","authors":"R. Ramesh, N. Murugan","doi":"10.11127/IJAMMC.2013.02.055","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.055","url":null,"abstract":"Friction stir processing (FSP) is an emerging novel, green and energy efficient processing technique to fabricate surface composites which is based on the basic principles of friction stir welding. The distinct advantages of friction stir processing are microstructural refinement, densification, homogeneity, accurate control and variable depth of the processed zone. Metal matrix composites, particularly Aluminium based metal matrix composites, reinforced with ceramics were developed as an alternative to materials with superior strength to weight ratio and strength to cost ratio, high stiffness, and thermal stability, which effect on improving wear, creep and fatigue resistance. However, these composites also suffer from low ductility and toughness due to the incorporation of ceramic reinforcements. For many applications, a combination of high surface wear resistance and high toughness of the interior bulk material required. In those situations, it is desirable that only the surface layer of components is reinforced with ceramic particles while the bulk retains the original composition and structure with higher toughness. In this paper, the details about the fabrication of Al 7075-T651 B4C surface composite by FSP to have improved surface hardness are provided. A tool made of high carbon high chromium steel and hardened to 62 HRC, having cylindrical profile was used for FSP. By using SYSTAT software regression model has been developed for predicting microhardness of processed surface composite. The fabricated surface composites were examined using optical microscope and found defect free friction stir processed zone. It was also observed that Boron Carbide particles were uniformly distributed and well bonded with the matrix alloy fabricated at high heat input condition. It was found that the average hardness of friction stir processed surface composite was 1.5 times higher than that of the base metal aluminium 7075 – T651. The increase in hardness was attributed to fine dispersion of B4C particles and fine grain size of the aluminium matrix. Friction Stir Processing [1] is a new, solid state processing technique for microstructural modifications, which was developed based on the principle of friction-stir welding (FSW). A non-consumable rotating tool with a pin and shoulder is inserted into the material and travelled along the desired path. Because of this the frictional heat is generated and the material undergoes severe plastic deformation, resulting in significant microstructural modification in the processed zone. FSP creates a region called the Nugget or Stir zone, where the refinement of microstructure takes place producing equiaxed fine grains with high grain boundaries. Figure 1 shows the step by step procedure of Friction Stir Processing. Fig.1 Friction Stir Processing (a) Rotating tool prior to contact with the plate; (b) Tool pin contacts plate creating heat; (c) Shoulder of tool contacts plate restricting further penetration while expa","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127148731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.082
Ananda G.K., H. Ramesha
{"title":"Study the Thermal Characteristics of LM13/ MgO Composites","authors":"Ananda G.K., H. Ramesha","doi":"10.11127/IJAMMC.2013.02.082","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.082","url":null,"abstract":"","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127814221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-13DOI: 10.11127/IJAMMC.2013.02.072
N. Khan, K. Ravi
Present day aircraft industry is focusing on weight reduction and fuel usage optimization which would ultimately lead to greener aero structures. The major challenge is the material selection by considering the design, operation and accidental scenarios. Composites have been considered along with advanced aluminum alloys for aero structures. One of the extreme operational scenarios is foreign object damage onto aircraft outer surfaces. The papers focus on the impact capability analysis of composites and aluminum alloys. Overall methodology of meeting the certification requirement is discussed using numerical tools. Finite Element of an aircraft windshield & surround structure for the bird-strike requirement according to the Federal Aviation Administration (FAA) Certification Specifications is discussed. Various methods of bird modeling and impact analysis is presented. Analysis is made based on the obtained numerical results. The Analysis Software used for the impact analysis were LS-Dyna and Ansys along with Hyper-mesh was used for pre-processing (Mesh). The geometry is developed using Catia. The objective of the paper is to bring out the simulated impact strength of the aircraft panels get an insight into the impact strength while meeting other criteria. Analysis high lights the need for considering extreme operation scenario like bird strike (Impact) while aiming for better material options for aircraft structures. New Materials for aircraft structures have been developed to meet the growing demands of the weight reduction and better fuel usage optimization. While the research has been focusing on the strength and density aspect of material options like aluminum and composites extreme operational scenario like Foreign Objects Damage will induce high impact loads onto to structures. The criteria are addressed in FAA regulations. As the problems impact highly non linear in nature certification based on numerical results has been a challenge. Future materials development model should be directed to address the impact loads that areexpected during operation [1]. Focus of static strength and density criteria should also include the dynamic failure mechanisms like bird strike. In current work existing models of bird in numerical tools like LSDYNA is used. Meeting the Certification requirement can be better understood by using numerical tools. This is help us in final applicability og material while choosing design direction. Due to increased air traffic in recent decade’s bird strike is seen as major threat to air safety. In addition higher flight speed (high Mach) is leading to higher kinetic energy and huge impulsive force generation during the impact conditions. The probability of bird hit on outer surfaces of the aircraft is high based on earlier experience. The date available in the open literature shows the projected parts of fight need attention. The loss of life due to bird strike has been recorded to be significantly high number. Among the
{"title":"Foreign Object Damage Analysis of Aircraft Structural Materials","authors":"N. Khan, K. Ravi","doi":"10.11127/IJAMMC.2013.02.072","DOIUrl":"https://doi.org/10.11127/IJAMMC.2013.02.072","url":null,"abstract":"Present day aircraft industry is focusing on weight reduction and fuel usage optimization which would ultimately lead to greener aero structures. The major challenge is the material selection by considering the design, operation and accidental scenarios. Composites have been considered along with advanced aluminum alloys for aero structures. One of the extreme operational scenarios is foreign object damage onto aircraft outer surfaces. The papers focus on the impact capability analysis of composites and aluminum alloys. Overall methodology of meeting the certification requirement is discussed using numerical tools. Finite Element of an aircraft windshield & surround structure for the bird-strike requirement according to the Federal Aviation Administration (FAA) Certification Specifications is discussed. Various methods of bird modeling and impact analysis is presented. Analysis is made based on the obtained numerical results. The Analysis Software used for the impact analysis were LS-Dyna and Ansys along with Hyper-mesh was used for pre-processing (Mesh). The geometry is developed using Catia. The objective of the paper is to bring out the simulated impact strength of the aircraft panels get an insight into the impact strength while meeting other criteria. Analysis high lights the need for considering extreme operation scenario like bird strike (Impact) while aiming for better material options for aircraft structures. New Materials for aircraft structures have been developed to meet the growing demands of the weight reduction and better fuel usage optimization. While the research has been focusing on the strength and density aspect of material options like aluminum and composites extreme operational scenario like Foreign Objects Damage will induce high impact loads onto to structures. The criteria are addressed in FAA regulations. As the problems impact highly non linear in nature certification based on numerical results has been a challenge. Future materials development model should be directed to address the impact loads that areexpected during operation [1]. Focus of static strength and density criteria should also include the dynamic failure mechanisms like bird strike. In current work existing models of bird in numerical tools like LSDYNA is used. Meeting the Certification requirement can be better understood by using numerical tools. This is help us in final applicability og material while choosing design direction. Due to increased air traffic in recent decade’s bird strike is seen as major threat to air safety. In addition higher flight speed (high Mach) is leading to higher kinetic energy and huge impulsive force generation during the impact conditions. The probability of bird hit on outer surfaces of the aircraft is high based on earlier experience. The date available in the open literature shows the projected parts of fight need attention. The loss of life due to bird strike has been recorded to be significantly high number. Among the ","PeriodicalId":207087,"journal":{"name":"International Journal of Advanced Materials Manufacturing and Characterization","volume":"8 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132471219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：