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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.

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).

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.

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 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 increased use of electronic systems has become a severe concern for electromagnetic pollution, leading to the development of materials to reduce electromagnetic interference (EMI). The present study investigated the EMI-shielding effectiveness (EMI-SE) of flax fiber polymer composite (FFC) in the available free space method by varying the wt.% of Rice husk ash (RHA) and hematite. The flax fiber was coated with the dip coating technique, and the coated fibers were used for preparing FFC by hand layup. The EMI-SE was measured at 32-33.5 dB in the X-band frequency range (8-12 GHz). As the cost is low and can be mass-produced, results show that the developed FFC are suitable for electric vehicle applications specifically to shield Electronic control units (ECU), where the interference effect needs to be reduced.

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.

In the last decade, there was growing interest in the use of green composites because of their environment-friendly nature, improvement in mechanical & chemical properties, better processability, and low cost. In this work, short sisal fiber was reinforced in a polycaprolactone (PCL) matrix and four different degradable green composites were developed with different weight fractions. Experimental studies were conducted as per standard to find the mechanical properties of PCL based composites. The data obtained shows that there is a 22% increase in tensile strength, 18% increase in hardness and 100% increase in impact strength for the specimen with 10% sisal fiber compared to neat PCL specimen. The mechanical property reduces when the fiber content is increased to 15%. These PCL based composites shall find applications in the packaging industry and consumer goods that have less service temperature.

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.

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.