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The present research investigates the corrosion behavior of aluminum metal matrix composites (AMMCs) in NaCl solution. The test was designed and performed based on Taguchi’s L8 orthogonal array. The stir casting technique fabricates the AMMCs, and silicon carbide (SiC) is individually reinforced in Al 6061 and Al 5052 matrix. The SiC particle are reinforced in a matrix with 5% and 10% separately in Al 6061 and Al 5052. The test variables used during corrosion studies were reinforced Al matrix, wt% of SiC, molar solution, and corrosion duration for stir-casted composite samples. The Al 6061 and Al 5052 composites were tested in 1M and 2M molar NaCl solutions for 15 and 30 days exposure duration. According to ASTM G31, the solution immersion tests were carried out. The corrosion surfaces are examined by optical microscope and field emission scanning electron microscopy (FESEM) equipment. Through microstructure, it is noted that the corrosion concentration is along the grain boundaries.

This study reports a simulation model to predict the coating thickness during the Electric Discharge Coating (EDC) process and validates it with experimental analysis. Solid lubricant coating was developed on the mild steel substrate using WS2, and Cu (50:50) based green compact electrodes. The simulation model developed by using COMSOL Multiphysics (5.5) software and the accumulated growth height from the heavy species transport calculated as coating thickness. Experiments with the same input parameters and coating thickness were measured, compared with simulation result and the results show with error fraction of 3% to 12%. Therefore, the present developed simulation model can be employed to predict the thickness of solid lubricant coating by EDC process with minimum error.

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.

Aluminum-based metal matrix composites are continuously changing to meet the industry’s specialized needs. In the aluminum alloy series, the AA5052 had a lightweight, high strength, good weldability, excellent corrosion resistance, and a good surface finish during the machining operation. The present work is to improve the mechanical characterization of AA5052 by adding 1 and 2 wt % of Aluminium Titanate (Al2TiO5) reinforcement particles through a stir casting process. The influences of Al2TiO5 reinforcement particle’s microstructural analysis were investigated. The tensile, impact and hardness of the AA5052/ Al2TiO5 composites were also determined by Universal Testing Machine (UTM), Charpy, and Vickers microhardness tester, respectively. The AA5052/ 2%- Al2TiO5 composite microstructure shows a uniform grain distribution. The increased wt 2 % of reinforced particles to AA5052 resulted in an improved microhardness (73.4 HV) and tensile strength (210.28 Mpa).

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.

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.

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.

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).

LED technology improved its efficacy through its innovative structures and development. General lighting and automobile industries are rapidly shifting from halogen lamps to LED lamps. LED is popular due to its high lumen output and efficiency which is considered a significant advantage. LED produces localized heat at its junction which directly affects its maximum lumen output range and even leads to failure. The conventional method for LED thermal management involves passive cooling using heat sinks and coolant fluid. The present work emphasizes active cooling of LED array considering various real- time parameters such as junction temperature, ambient and heat sink temperature. The LED experiences active cooling with the help of the feedback system loop controlling the junction temperature by varying the fan speed based on the heat sink temperature sensor output.

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.

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.

This study examines the influence of cryogenic treatment on the microstructure and on the physical properties of the rapid prototype SLS material. The wear properties of the rapid prototype SLS material both before and after cryogenic treatment are studied in three phases. Phase I deals with the sample preparation through the SLS technique; Phase II involves the preliminary tests like roughness test, hardness test, SEM and wear test. Phase III is the cryogenic treatment of the sample in the setup designed. The cryogenic coolant used is Nitrogen, having a boiling point of 77 K, and the whole treatment process takes about 2 to 3 days. Phase IV deals with the testing of the cryogenically treated samples in which similar tests to that in Phase I are carried out. These results are tabulated and graphs are plotted. Furthermore, the percentage change in the hardness and wear properties of the samples are found.

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.

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.