No abstract

Friction Stir Welding is a solid state welding processused in aerospace, automobile and machine tool industry. However, corrosion of the friction stir weld zones is still a major drawback that needs to be addressed immediately; hence the current work focuses on the corrosion characterization of the friction stir weld joints of dissimilar aluminium alloy. In the present research, friction stir welding is carried out at different set of parametric conditions and the weld joints are characterized for weight loss corrosion in sodium chloride saline medium. The friction stir weld joints of dissimilar aluminium alloys are obtained using three sets of process parameters viz., tool profiles of straight cylinder, taper cylinder, and straight triangular; tool rotational speed of 800 rpm, 1000 rpm, and 1200 rpm; tool feed rate of 100 mm/min, 120 mm/min, and 140 mm/min; tool offset of 0.5 mm, 0 mm, and-0.5 mm. The corrosion characterization is carried out for friction stir weld joint using immersion tests. The results give an overview of the variation in the corrosion with time, and the effect of process parameters on the corrosion behavior of weld joints.

Natural fiber-reinforced polymer composite is a rapidly growing topic of research due to the simplicity of obtaining composites that is biodegradable and environmentally friendly. The resulting composites have mechanical properties comparable to synthetic fiber-reinforced composites. In this regard, the present work is formulated with the objectives related to the development, characterization, and optimization of the wt% of reinforcements and the process parameters. The novelty of this work is related to the identification and standardization of the appropriate wt% of reinforcements and parameters for the processing of the areca nut leaf sheath fiber-based polymer composites for enhanced performance attributes. With this basic purview and scope, the composites are synthesized using the hand layup process, and the composite samples of various fiber compositions (20%, 30%, 40%, and 50%) are fabricated. The mechanical characteristics of biodegradable polymer composites reinforced with areca nut leaf sheath fibers are investigated in the present work, with a focus on the effect of fiber composition (tensile properties, flexural strength, and impact strength). The properties of composites are enhanced by combining the areca nut leaf sheath fiber and epoxy resin, with a fiber content of 50% being the optimal wt%. The Scanning electron microscopy (SEM) investigations also ascertain this by depicting the good interfacial adhesion between the areca nut leaf sheath fiber and the epoxy resin. The tensile strength of the composite specimen reinforced with 50% areca nut fiber increases to 44.6 MPa, while the young’s modulus increases to 1900 MPa, flexural strength increases to 64.8 MPa, the flexural modulus increases to 37.9 GPa, and impact strength increases to 34.1 k J/m2. As a result, the combination of areca nut leaf sheath fiber reinforced epoxy resin shows considerable potential as a renewable and biodegradable polymer composite. Furthermore, areca nut leaf sheath fiber-reinforced epoxy resin composites are likely to replace petroleum-based polymers in the future. The ecosustainability and biodegradability of the composite specimen alongside the improved mechanical characteristics serve as the major highlight of the present work, and can help the polymer composite industry to further augment the synthetic matrix and fiber-based composites with the natural fiber-reinforced composites.

The use of natural fiber-reinforced polymer composites has increased over a period of time, majorly due to the ecosustainability and biodegradability of the composites. Among several grades of natural fibers, bamboo fibers offer numerous environmental and cost benefits and possess excellent mechanical characteristics. The superior properties of the bamboo fibers have triggered the research interests in the domain of bamboo fiber-reinforced polymer composites. Among the polymers, polyesters are long chain molecules made up of atoms arranged in various ways with other elements to form the basic building blocks of a polymeric chain. Polyester is being increasingly employed in today’s industrial products due to its inherent advantages. As a result, based on the potential properties of bamboo fibers as reinforcing materials and polyester resin as matrix material, the biocomposites are synthesized by hand lay-up technique and the specimens cut as per the standard dimensions and subjected to mechanical investigations, vibration, and morphological characterization as per the ASTM test methods. The increase in fiber weight content has enhanced flexural, tensile, and impact characteristics and improved the damping characteristics of the composite specimens. The microstructural evaluations have revealed the uniform distribution of the bamboo fibers in the resin, and the morphological studies of the fractured specimens have revealed that the fracture is majorly due to the matrix cracks rather than the fiber debonding, which is a major attribute ascertaining the strong coherent strengthening mechanism brought about by the inclusion of bamboo fiber in the polyester resin.

Welding process in vehicle structures has gained importance, especially for better strength and mechanical properties. Hence, there is vast research going on in the domain of newer welding techniques. Friction Stir Welding (FSW) is one of them. FSW is used in this research to join two different grades of aluminium alloys by varying the process parameters. The process parameters are optimized based on the Design of Experiments (DoE) and the Taguchi techniques. From the experimental findings for different process parameters, the optimized set of conditions involving the normal, transverse forces and the torque are determined. Further, the process methodology is validated.