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Dissimilar metal welds (DMWs), between austenitic stainless steel (ASS) and micro alloyed high strength low alloy steel (HSLA), are used in high temperature applications in power stations and petrochemical plants. The gas metal arc welding (GMAW) has surpassed the shielded metal arc welding (SMAW) process due to its advantages of producing fast, long, clean continuous weld at any position [1, 2, 3, 4, 5]. A studies on mechanical and metallurgical properties of conventional V-groove SMAW and GMA Welding of dissimilar 20 mm thick 304LN ASS and micro alloyed HSLA steel plate were carried out by using austenitic E308L- 15 electrode with gas tungsten arc welding (GTAW) root pass. The tensile (axial and all-weld) properties, hardness and microstructure of the weld and HAZ are analyzed.

Duplex stainless steel (DSS) 2205 grade is welded with austenitic filler wires (ERNiCrMo-3 and ERNiCrMo-4) using gas tungsten arc welding (GTAW) process to operate at marine environments. Microstructure using optical (OM) and scanning electron microscopes (SEM) with energy dispersive spectroscope (EDS) are utilized to examine the metallurgical characterization of DSS 2205 weldments. Microhardness, impact, and tensile tests are employed to obtain the mechanical properties of weldments. Secondary precipitates such as Mo23C6 and Cr23C6 are formed in the ERNiCrMo-3 weldment which reduced the mechanical properties. In this study, ERNiCrMo-4 filler wire is provided enhanced mechanical properties for welding DSS 2205.

The use of natural fibers composite matrix is tremendously increasing day to day and acting as a replacement product to many conventional materials in the automobile and aviation sectors. It was preferred due to its bio-degradability, weight to strength ratio, easy availability, and lightweight. The crisscrossed woven jute and raw-sisal fibers had drawn the superior properties in the advanced developing field of the composite. The main purpose of this project is to evaluate the mechanical properties and the influence of raw sisal fiber with woven Jute/Epoxy composite by varying the size of raw sisal in three variable lengths such as 10mm, 20mm, and 30mm respectively. The composite laminates were fabricated by the conventional hand-layer technique. The mechanical characterization like the tensile test, flexural test, and hardness, was estimated on the fabricated jute/sisal hybrid composite material.

The utilization of Additive Manufacturing (AM) technology in the current manufacturing sector is growing day - by - day. This is made possible by the constant development of new materials and techniques to overcome the difficulties that are encountered while fabricating a part. In AM, parts are fabricated by laying successive layers on one another till the complete part is build. This gives AM an edge over conventional manufacturing. Even intricate or hollow parts can be fabricated with the same ease as fabricating a solid part. The key objective of this project is to evaluate and compare mechanical properties of Polyethylene Terephthalate - Glycol modified (PETG) and Carbon fiber reinforced Polyethylene Terephthalate - Glycol modified (CF - PETG), which are fabricated using Fused Deposition Modelling (FDM) process of AM. The ASTM standards D638 and D790 were followed for fabricating tensile test and Flexural test specimens respectively.

The current work investigates the hot corrosion demeanour of Hastelloy X weldment produced with autogenous mode through key-hole plasma arc welding (K-PAW). The hot corrosion test has been performed for weldment in molten salt-1 (MS-1) (75 % Na2SO4 + 25 % V2O5) and molten salt-2 (MS-2) (75 % Na2SO4 + 20 % V2O5 + 5 % NaCl) circumstance for 25 hrs (25 cycles) at 900 °C. The MS-1 substrate of both base metal and weldment provided the lowest weight gain than the MS-2 substrate. The NaCl in the MS-2 causes severe hot corrosion on the substrate, whereas the absence of NaCl in MS-1 reduces the hot corrosion effects. The highest parabolic constant is observed for K-PAW weldment in MS-2 condition. The tendency of hot corrosion rate follows the order of, Base Metal MS-1 < K-PAW MS-1 < Base Metal MS-2 < K-PAW MS-2. The occurrence of protective phases like chromium oxides (Cr2O3), spinel oxides (NiCr2O4 and NiFe2O4) Nickel oxide (NiO) on the substrate resist the further oxidation.

The present paper examined the machining of Nimonic 75 experimentally with hexagonal boron nitride-based cutting fluid. Three different types of hexagonal boron nitride (hBN) nanofluids with various hBN concentrations and cutting variables (cutting speed and feed rate) are applied in turning experiments. Tool wear, cutting forces, roughness, residual stress, and chip morphology in machining Nimonic 75 alloy with the hBN nanofluids are analyzed. The effects caused by the variation of hBN concentration and cutting variables are discussed. The results show that cutting speed decrease the force, surface roughness, specific energy consumption, and chip reduction coefficient except for shear angle, friction coefficient, and residual stress. The increase in feed rate increases the machining characteristics and chip-tool interface indices parameters except for flank wear and specific energy consumption.

The research aims to optimize the surface roughness, material removal rate (MRR), tool wear, and spark gap for input machining parameters such as Pulse on-off time and wire feed rate. The experiment results of WEDM of Duplex stainless steel are optimized by ANOVA and Response surface methodology (RSM) approach. Taguchi’s orthogonal array L9 (3*3) was used to design the test condition for the experiment. After the model validation, ANOVA was used to identify the most significant input factor on the output. Response surface methodology was used to find the ideal cutting conditions which produce the best-desired output in terms of less tool wear, lower surface roughness, lower spark gap, and higher material removal rate. The optimal MRR, Spark Gap, surface roughness, and tool wear parameters for Duplex Stainless Steel are obtained at Pulse on 110.23, Pulse off time of 56.0, and a wire feed rate of 1.0.

The objective of the study is to investigate the effect of current pulsation frequency on the weld bead microstructure, segregation and hardness of Hastelloy C-2000 weldments. Bead on Plate (BoP) welds were made by using Pulsed Current Gas Tungsten Arc Welding method (PCGTAW) at eleven different frequencies. The weld bead width and depth of penetration was measured with the help of Dinolite macro analyzer. The microstructure of weldments are further examined through optical microscope and Scanning Electron Microscopy (SEM) to identify the type of grain, grain coarsening and extent of the Heat Affected Zone (HAZ). The grain structure turn into finer and equiaxed in all cases and there was an optimum frequency range over which the significant grain refinement was observed. Microsegregation of alloying elements were computed with the aid of Energy Dispersive X-ray Spectroscopy (EDS). Vickers Hardness Tester was used to measure the hardness of the weld samples at ambient conditions.

Aluminium metal matrix composite are broadly used in various field like aerospace, marine and automobile application. The application of composites necessitates joining process and its difficult due to different materials. To address the considering difficulties the present study is, Cr2O3 was reinforced in Al 6061 matrix in 2 % to 6 % in the incremental step of 2 %. The stir casting method was used to fabricate the composites with 300 rpm stirring speed and the stirring time duration was 3 min throughout the fabrication process. The H13 tool is used for prepared friction stir welded (FSW) joints and tool having 6.7 mm pin diameter and 6 mm pin height. The fabrication process is conducted by 500 rpm and 700 rpm tool rotational speed with 50 mm/min and 60 mm/min welding speed receptively. The atmospheric environmental condition was preferred to perform friction stir welding.

Inconel 617 is found in industrial sectors, including chemical, petrochemical, and nuclear. This work mainly concentrates on the analysis and the input-parameters optimization that minimizes the surface roughness, tool wear, and force in turning Inconel 617. Then, the chip and inserts are morphologically characterized using optical images. The residual plots showed that the accomplished investigational data are reliable and suitable for further study. Abrasion is accountable for tool wear mechanisms, and a rise in cutting speed affects the tool wear profile. Chip burr adhering to the flank surface is responsible for the surface roughness increase. Optimum cutting parameters are determined as 0.3mm depth of cut, 0.1mm/rev feed rate, and 220m/min cutting speed. Feed rate is the most influential parameter for process variables through Criteria Importance through Inter Criteria and weighted aggregated sum product assessment methodology.

The present paper mainly focuses on the analysis and multi-factor optimization of cutting process parameters in turning Hastelloy C-276 using an integrated approach of Weighted Aggregated Sum Product Assessment (WASPAS) and criteria importance through inter-criteria correlation (CRITIC). To achieve this objective, a design of experiment (DoE) is employed for the three control parameters: cutting speed, feed rate, and cutting depth. The insert used for turning is a coated carbide insert (PVD: Ti-Al-N). Different responses are recorded: force, tool wear, and surface roughness in machining attributes, chip structure, chip thickness, chip thickness ration, shear angle, and friction coefficient in chip-tool interface indices. Uncertainty probabilistic study depends on Monte Carlo (MC) method applied.

The developed model analysis is built in matrix runs to optimise the friction stir welding parameters of rotational speed, welding speed, shoulder diameter and tilt angle in this research. The aim of any design is to maximise the welded properties, either to surpass the base metal properties. The model that is created is the product of a number of regression methods that have been tested for adequacy. In this model we have taken three levels of varying parameters shoulder diameters, rotational speed, welding speed. Mathematical model is developed for the effect of three process parameter at three levels using response surface methodology (RSM).

The current research work scrutinized the influence of plasma arc in the metallurgical and mechanical behavior of Nimonic 80A weldment. Defect free weld bead of 6 mm thickness was achieved in a single pass through plasma arc welding. The microstructure of weldment is decorated with cellular dendritic structure at the center and at the weld interface region columnar dendritic structure was observed. Metallurgical analysis showed the Cr and Ti secondary precipitates in the interdendritic region of the WZ. The existence of M23C6 and Cr2Ti were observed through the X-ray diffraction analysis. Both tensile test and microhardness test were conducted to study the mechanical properties of weldment. The result concluded that both the strength and ductility inferior than base metal and the hardness of the weld bead is similar to that of BMl.

This work inspects the metallurgical and tensile demeanor of pulsed current gas tungsten arc welded ERNiCrCoMo-1 filler wire on alloy 80A weldment. Defect free weldment was achieved in a four pass through PCGTA welding. The center of the weld microstructure is decorated with equiaxed dendritic structure and columnar dendritic structure. SEM analysis showed the existence of Mo, Fe and Ti secondary phase precipitation in the grain boundary region of the weld zone. Tensile testing was conducted to analysis the strength and ductility of weldment. The result showed that the tensile strength and ductility were lower than that of base metal (BM).