Effect of deposition of nanoparticles during joining of dissimilar metals by friction stir welding

Friction stir welding (FSW) is a solid–state, hot–shear joining process in which a rotating tool with a pin moves along the butting surfaces of two rigidly clamped plates placed on a backing plate. FSW has evolved as an alternative joining technique for aluminium and is gaining research importance on non-conventional weldable alloys, which improves the strength of the welded joint when compared to the fusion welding process. The earlier research studies on joining of similar and dissimilar metals by varying process parameters to identify change in mechanical properties of weldments can be seen in the literature. In all the studies reported earlier, one can find optimized values of process parameters either for similar or dissimilar alloy joints. Also the composites produced by friction stir processing enhance the mechanical properties of the material. The strength of the welded joint can be further enhanced by the addition of reinforcements into the metal matrix during friction stir welding. Hence, there is a necessity to study the joining of dissimilar aluminium alloys by depositing the nano particles during the friction stir welding. With this motive, the present research aims out to study the effect of dissimilar aluminium alloy joints by depositing nano particles. Experimentation has been carried out on medium strength aluminium alloys AA5052 and AA6063.The effect of copper nanoparticles addition on the strength of welded joint has been studied during friction stir welding. Further, in order to understand the influence of nanoparticles deposition on high strength aluminium alloys AA2024 and AA7075 the reinforcements like multi-walled carbon nanotubes, titanium dioxide and aluminium oxide were studied at various process parameters. The mechanical properties of the welded joint with and without nanoparticles are evaluated which are correlated with the microstructure study by optical microscope. The results show an improvement in mechanical properties due to the addition of nanoparticles in the joints fabricated, compared to that of that of bare joints. The tensile strength and microhardness of the welded joint was improved by 8.01% and 23.7% at 90 mm/min, when compared to the welded joint without CNT nanoparticles for high strength dissimilar aluminium alloys.This behavior was further supported by Electron dispersive X-ray analysis (EDX) study, which provides elemental identification and quantitative compositional information. It has been found that the distribution of nanoparticles was influenced by the groove size and the mechanical properties were found to be enhanced with groove of 1 mm width. It has been observed that the maximum % increase in strength and microhardness for the samples with CNT nanoparticles is about 6.59% and 20%. The improvement of strength and hardness was more with TiO2 nanoparticles.Thus, by controlling the process parameters and groove size the distribution of nanoparticles and mechanical properties of the welded joint were enhanced effectively, but varied depending on the type of reinforcement added during friction stir welding process

Effect of Groove Size on Mechanical Properties and Microstructure Due to Reinforcement Addition in Friction Stir Welded Dissimilar Alloys

Friction stir welding is a solid state joining technique, which improves the strength of the welded joint when compared to the fusion welding process. The strength of the welded joint can be further enhanced by the addition of reinforcements into the metal matrix during friction stir welding. In the present research, the dissimilar aluminium alloys AA5052 and AA6063 were welded by varying the groove size in order to estimate the strength of the joint due to reinforcements. The results show that varying the groove size influences the mechanical properties of the welded joint due to the variation of reinforcement’s deposition in the stir zone. The microstructure and elemental identification also show that the deposition of reinforcements was dependant on the groove size. Also, the width of the groove size plays a significant role on the strength of the welded joint, and maximum microhardness was found to be 150.08Hv for the groove size of 1 mm×2 mm

Evaluating the Strength of the Friction Stir Welded Joints at Various Rotational Speeds

The present research paper aims in evaluating the strength of the welded AA6351 alloy plates of 6 mm thick by using friction stir welding technique at different rotational speeds The applied welding technique is capable of achieving the mechanical properties of the alloy close to that of the original alloy. In the present investigation, the speeds of the spindle were varied from 1100 rpm to 1500 rpm with a constant transverse speed of 20 mm/min. The tensile strength of the joints is determined by an universal testing machine. The results from the present investigation show that the values of the yield strength were very much closer to the values of the AA6351Alloy prior to welding. It has been found from the experiments that the strength of the joints increases with the increase in the rotational speed; however, the same is decreasing after achieving certain speed

Effect of Welding Speed on Microstructure and Mechanical Properties due to The Deposition of Reinforcements on Friction Stir Welded Dissimilar Aluminium Alloys

The strength of the welded joint obtained by solid state stir welding process was found to be improved as compared to fusion welding process. The deposition of reinforcements during friction stir welding process can further enhance the strength of the welded joint by locking the movement of grain boundaries. In the present study, the aluminium alloys AA2024 and AA7075 were welded effectively by depositing the multi-walled carbon nanotubes in to the stir zone. The mechanical properties and microstructures were studied by varying the traverse speed at constant rotational speed. The results show that rotating tool pin stirring action and heat input play an important role in controlling the grain size. The carbon nanotubes were found to be distributed uniformly at a welding speed (traverse speed) of 80mm/min. This enhanced the mechanical properties of the welded joint. The microstructure and Electron dispersive X-ray analysis(EDX) studies indicate that the deposition of carbon nanotubes in the stir zone was influenced by the traverse speed

Effect of Rotational Speed on Mechanical Properties and Microstructure Due to the Addition of Reinforcements on Friction Stir Welded Dissimilar Aluminum Alloys

The Friction Stir Welding is a solid state joining process, which has many advantages in welding similar and dissimilar aluminium alloys when compared with the traditional fusion welding process. In the present investigation dissimilar aluminium alloys AA5052 and AA6063 were joined by friction stir welding by inserting Cu nanoparticles as reinforcements to study the effect of the same. Butt joints were obtained in 6mm thick plates with a longitudinal speed of 200mm/min, and at a load of 1.5kN with a rotational speed of 1200 and 1400 rpm. In order to determine the effect of process parameters due to the addition of Cu nanoparticles on microstructure and mechanical properties in dissimilar aluminium alloys was investigated. The result shows that due to the addition of reinforcements, the mechanical properties were improved, as the process parameters are changed. This behaviour was further supported by Electron dispersive X-ray analysis (EDX) studies, which provides elemental identification and quantitative compositional information

Prediction of Temperatures During Friction Stir Welding of AA6061 Aluminium Alloy Using Hyperworks

This document contains the formatting information for the papers presented at the International conference on “Engineering Technology International Conference”. The conference held at (Bali, Indonesia) during August 10-11, 2015. The microstructure and mechanical properties of the material to be welded mainly depends on the temperature during welding. The difficulty in measuring these temperatures during friction stir welding, pose a serious concern to researchers, practicing engineers and technicians. Hence, there is a necessity for searching alternate solutions. In the present research, a simulation model has been developed by using hyper works software to estimate the temperatures and flow stress. The modeling of Friction Stir Welded AA6061 alloy has been carried out by three dimensional nonlinear FEA model, the temperatures are evaluated. During the welding process the peak temperatures and flow stresses are presented around the rotating tool pin, and plates are found to be 615 0 C and 450 0 C

Effect of Nano Particle Deposition on Mechanical Properties of Friction Stir Welded Dissimilar Aluminium Alloys by Taguchi Technique

Improving the mechanical properties while joining of dissimilar alloys by FSW has been a choice of research during the past decade. Hence, an attempt has been made in the present research to join dissimilar Al alloys (AA5052 and AA6063) by addition of Copper nanoparticles in the weld joint. A 5T NC FSW machine has been employed to perform the desired task. To achieve optimum values of the process parameters, an optimization study has been carried out using Taguchi technique. The results obtained from the optimization studies and experimental investigations match very well proving the efficacy of the study. The results from the investigation show an improvement in mechanical properties when Cu nanoparticles are deposited which are further supported by microstructure and EDX analysis

Influence of groove size and reinforcements addition on mechanical properties and microstructure of friction stir welded joints

The butt joints fabricated by friction stir welding were found to have more strength than the joints obtained by conventional joining process. The important outcome of this process is the successful fabrication of surface composites with improved properties. Thus in order to further enhance the strength of the dissimilar alloy joints the reinforcements can be deposited in to the aluminium matrix during the process of friction stir welding. In the present study the multi-walled carbon nanotubes were embedded in to the groove by varying the width during joining of dissimilar alloys AA2024 and AA7075. Four widths were selected with constant depth and optimum process parameters were selected to fabricate the sound welded joints. The results show that the mechanical properties of the fabricated butt joints were influenced by the size of the groove, due to variation in the deposition of reinforcement in the stir zone. The microstructural study and identification of the elements of the welded joints show that the reinforcements deposition is influenced by the size of the groove. It has also been observed that the groove with minimum width is more effective than higher width. The mechanical properties are found to be improved due to the pinning of grain boundaries

Effect of Welding Speed on Microstructure and Mechanical Properties due to The Deposition of Reinforcements on Friction Stir Welded Dissimilar Aluminium Alloys

The strength of the welded joint obtained by solid state stir welding process was found to be improved as compared to fusion welding process. The deposition of reinforcements during friction stir welding process can further enhance the strength of the welded joint by locking the movement of grain boundaries. In the present study, the aluminium alloys AA2024 and AA7075 were welded effectively by depositing the multi-walled carbon nanotubes in to the stir zone. The mechanical properties and microstructures were studied by varying the traverse speed at constant rotational speed. The results show that rotating tool pin stirring action and heat input play an important role in controlling the grain size. The carbon nanotubes were found to be distributed uniformly at a welding speed (traverse speed) of 80mm/min. This enhanced the mechanical properties of the welded joint. The microstructure and Electron dispersive X-ray analysis (EDX) studies indicate that the deposition of carbon nanotubes in the stir zone was influenced by the traverse speed

Effect of Welding Speed on Microstructure and Mechanical Properties due to The Deposition of Reinforcements on Friction Stir Welded Dissimilar Aluminium Alloys

The strength of the welded joint obtained by solid state stir welding process was found to be improved as compared to fusion welding process. The deposition of reinforcements during friction stir welding process can further enhance the strength of the welded joint by locking the movement of grain boundaries. In the present study, the aluminium alloys AA2024 and AA7075 were welded effectively by depositing the multi-walled carbon nanotubes in to the stir zone. The mechanical properties and microstructures were studied by varying the traverse speed at constant rotational speed. The results show that rotating tool pin stirring action and heat input play an important role in controlling the grain size. The carbon nanotubes were found to be distributed uniformly at a welding speed (traverse speed) of 80mm/min. This enhanced the mechanical properties of the welded joint. The microstructure and Electron dispersive X-ray analysis (EDX) studies indicate that the deposition of carbon nanotubes in the stir zone was influenced by the traverse speed