N. Rajesh Jesudoss Hynes

Investigation on Joining of Aluminum and Mild Steel by Friction Stud Welding

Joining of dissimilar metals has various automotive, aerospace, nuclear, chemical, and cryogenic applications. The present study focuses on friction stud welding of aluminum and mild steel. Experiments had been conducted by varying the process parameters and the strength of the friction welded joints was evaluated. Experimental results show that the speed of rotation, friction time, and axial shortening distance have significant effect on the impact strength of the welded joints. The dissipation of frictional heat from the weld center results in temperature gradient across the welded joint, causing different zones with different microstructures. Scanning electron microscope (SEM) micrograph reveals the presence of three distinctive regions in the heat-affected zone, namely, fully plasticized deformed zone, partially deformed zone, and unaffected base metal zone. The microhardness values were measured across the welded joint. At the interfacial region, there is an increased plastic deformation. This is due to the rise in heat input during friction stage and applied upsetting load in the forging stage. Consequently, there is an increase in hardness at the interfacial region of the welded joint.

Physicochemical and Thermal Properties of Ceiba pentandra Bark Fiber

ABSTRACT Owing to their low weight-to-high strength ratio and recyclable features, the natural fibers are the most potential choice in place of synthetic fibers and been used as reinforcement materials in polymer matrix composites. Characterization of Ceiba pentandra bark fibers (CPFs) such chemical analysis, Fourier Transform-Infrared Analysis (FTIR), X-ray diffraction, thermogravimetric analysis, and Differential thermogravimetric analysis (DTG) analysis has analyzed. CPFs contain 60.9% (w/w) of cellulose, 17.5% (w/w) of hemicellulose, and 23.5% (w/w) of lignin. Besides, its density and crystallinity index are 682 kg m−3 and 57.94%, respectively. TG and DTG analysis discovered that CPFs are thermally stable up to 342.1°C. Further, all the resources of CPFs ensured that it can be an excellent alternative for synthetic fibers in polymer matrix composites.

Electrochemical Machining of Aluminium Metal Matrix Composites

High performance aluminium based metal matrix composites possess low machinability characteristic. Electrochemical machining (ECM) is one of the advanced machining processes, used for machining of these newly developed exotic materials. This article critically reviews the research work on experimental investigations on ECM of aluminium matrix composites. Besides, recently developed techniques such as abrasive assisted electrochemical machining, electrochemical grinding, electrochemical micromachining, and electrochemical drilling are explored in the processing of aluminium metal matrix composites.

Influence of rotational speed on mechanical features of thermally drilled holes in dual-phase steel

Thermal drilling is a novel chipless sheet metal drilling process that uses a rotating thermal drill tool to pierce and form a bushing shape hole. In this work, thermal drilling process is successfully employed to drill the DP 600 grade–type galvanized steel with a thickness of 2 mm. The influence of different spindle rotational speeds such as 1600, 2000 and 2400 r/min on the formation of bushing height, surface roughness, microhardness and microstructure of the thermal-drilled holes are investigated in detail. Process parameters such as feed rate, thermal drill angle and workpiece thickness were held constant in order to explore the influence of rotational speed on the quality characteristics of the thermal drilling process. It has been found that the bushing height was improved with increasing of rotational speed, but the petal formation at the outer edge of the bush is decreased. Surface roughness tests indicate that the better surface quality drilled hole could be obtained at the highest rotational speed of 2400 r/min. The microstructural investigation confirmed that a new result of Lüders band marks was formed inside the thermal-drilled holes because high thermal stress and yielding of galvanized steel material.

Design and development of flapping wing micro air vehicle

Birds and insects have different methods of producing lift and thrust for hovering and forward flight. Most birds, however, cannot hover. Wing tips of birds follow simple paths in flight, whereas insects have very complicated wing tip paths, for hovering and forward flight, which vary with each species. FMAV based on avian flight. Development of Flapping Wing Air Vehicle (FWAV) is an on-going quest to master the natural flyers by mechanical means. It is characterized by unsteady aerodynamics, whose knowledge is still developing. The present work aims at include being capable of manoeuvring around and over obstacles by adjusting pitch, yaw, and roll, able to glide for five seconds under its own power, skilful at alternating between flapping and gliding with minimal disruption of flight pattern and being durable enough to withstand impacts with minimal to no damage.Birds and insects have different methods of producing lift and thrust for hovering and forward flight. Most birds, however, cannot hover. Wing tips of birds follow simple paths in flight, whereas insects have very complicated wing tip paths, for hovering and forward flight, which vary with each species. FMAV based on avian flight. Development of Flapping Wing Air Vehicle (FWAV) is an on-going quest to master the natural flyers by mechanical means. It is characterized by unsteady aerodynamics, whose knowledge is still developing. The present work aims at include being capable of manoeuvring around and over obstacles by adjusting pitch, yaw, and roll, able to glide for five seconds under its own power, skilful at alternating between flapping and gliding with minimal disruption of flight pattern and being durable enough to withstand impacts with minimal to no damage.

Production of aluminium metal matrix composites by liquid processing methods

Owing to high strength to low weight ratio, Aluminium matrix composites are widely used in diverse applications of many industries. This lucrative property is achieved by reinforcing the brittle ceramic particles in the aluminium matrix. Aluminium matrix composites are produced by liquid processing methods and solid processing methods. Nevertheless, liquidprocessing techniques stand out because of its simplicity and its suitability for mass production. In this review article, the production of aluminium matrix composites by different liquid processing technique is discussed and a comparative study is carried out.

Numerical simulation on influence of bonding temperature in transient liquid phase bonding

In this article, numerical simulation of transient liquid phase bonding of ceramic/metal joint has been carried out by using Finite Element Analysis (FEA) software. To increase the wettability, aluminium sheet was used as an interlayer. Hence, numerical simulation of TLP bonding process is done by varying the bonding temperature. Transient thermal analysis had been carried out for each cases and temperature distribution was predicted by the developed numerical model. From the simulation studies, it is found that the decrease in bonding temperature enhances favourable temperature distribution and eventually improves the joint efficiency of graphite/copper joints.

Numerical investigation on friction welding of alumina / AA 6063 T6 joints

Friction welding is the most suitable candidate for joining the dissimilar materials such as AA 6063 T6 alloy/Alumina for critical situations in high temperature and high corrosion resistance applications. In the present work, the numerical simulation was carried out to understand the mechanism of joining of AA 6063 T6 alloy/ Alumina rod by friction welding process. The developed thermo mechanical model is a highly nonlinear due to the interaction between the temperature fields and time dependent of the material properties. The developed numerical tool could be used to predict the temperature distribution, stress, strain and deformation of the dissimilar joints.

Finite element based simulation on friction stud welding of metal matrix composites to steel

Friction welding is a solid state joining technique used for joining similar and dissimilar materials with high integrity. This new technique is being successfully applied to the aerospace, automobile, and ship building industries, and is attracting more and more research interest. The quality of Friction Stud Welded joints depends on the frictional heat generated at the interface. Hence, thermal analysis on friction stud welding of stainless steel (AISI 304) and aluminium silicon carbide (AlSiC) combination is carried out in the present work. In this study, numerical simulation is carried out using ANSYS software and the temperature profiles are predicted at various increments of time. The developed numerical model is found to be adequate to predict temperature distribution of friction stud weld aluminium silicon carbide/stainless steel joints.

Simulation on friction taper plug welding of AA6063-20Gr metal matrix composite

Friction taper plug welding a variant of friction welding is useful in welding of similar and dissimilar materials. It could be used for joining of composites to metals in sophisticated aerospace applications. In the present work numerical simulation of friction taper plug welding process is carried out using finite element based software. Graphite reinforced AA6063 is modelled using the software ANSYS 15.0 and temperature distribution is predicted. Effect of friction time on temperature distribution is numerically investigated. When the friction time is increased to 30 seconds, the tapered part of plug gets detached and fills the hole in the AA6063 plate perfectly.