Antifungal Effect of Leaf Extract of Some Medicinal Plants Against \u3cem\u3eFusarium Oxysporum\u3c/em\u3e Causing Wilt Disease of \u3cem\u3eSolanum melogena\u3c/em\u3e L.

The antifungal effect of crude medicinal plant extracts of 20 plants species was determined by in vitro study using water, ethanol and acetone as a solvent following poisoned food technique. It was found that all the plant extracts at 50% concentration were effective in reducing the mycelial growth of Fusarium oxysporum f. sp. Melongenae Mauto and Ishigami. Among the 20 plant extracts, in different solvents, higher inhibition was noticed in 4 plants extracts namely Adhatoda vasica, Jatropha curcas, Sapindus emarginatus and Vitex negundo. These plants were selected further for different concentrations of 10%, 20% 30% and 40%. Among them Adhatoda vasica at 40% alone recorded 100% inhibition and remaining three plants produced almost similar inhibitory effect. At the low concentration of 10% Vitex negundo had more inhibitory effect (82%), while Jatropha curcas extracts showed very low inhibition (25%). There were not many differences in the inhibition between the extract of Adhatoda vasica and Sapindus emarginatus. In vivo pot culture experiment employing water extract of six plant species showed an increase in the root and shoot length and fresh and dry weight of root and shoot with the consequent reduction in the disease symptoms of the egg plant

Effect of double-side welding on the microstructural characteristics and mechanical performance of dissimilar AA6061-AA5052 aluminium alloys

In this study, cold metal transfer (CMT) based double-side welding process was employed to weld AA5052-H32 and AA6061-T6 plates having a thickness of 6 mm. The microstructure and mechanical integrity of the weldment was examined systematically. Symmetric and defect free joint with full penetration was achieved. The multiple heating and cooling cycles during CMT welding did not affect the weldment while the microstructure comprised of columnar and equiaxed dendrites and the heat affected zone (HAZ) width was < 50 µm at all interfaces. Precipitates such as Al3Mg2, Mg2Si, and α-Al(FeMn)Si were observed in the fusion zone. Intergranular Al-Si eutectic structure along with few microliquefaction cracks were noticed in the α-Al matrix. The maximum tensile properties for double-side welded joint were 214 MPa and 12.30 % with a joint efficiency of 70.68 %. Tensile specimens underwent ductile fracture in the weaker AA5052-H32 side with confined plastic deformation. © 2022 Elsevier B.V

Microstructure and Mechanical Properties of Dissimilar Aluminum Alloys AA5052-H32 and AA2219-T31 Welded Using Cold Metal Transfer Process

Lightweight structures fabricated from dissimilar aluminum alloys in aerospace and marine industries involve a lot of welding. Aluminum alloys AA5052-H32 and AA2219-T31 were successfully welded with the low heat input welding technology, the cold metal transfer (CMT) process. Microstructures indicated the existence of finer equiaxed dendrites and strengthening precipitates in the weld metal (WM). The microliquefaction cracks were discontinuous and propagated along the grain boundaries and with the grains of α-Al matrix in the WM. The tensile properties of the dissimilar welded joint attained a joint efficiency of 70.1 % and fracture ended in ductile nature with dimples and microvoids. The heat affected zone was narrow and noticed a drop in the hardness at both the interfaces caused by a softening phenomenon, ending up with coarse precipitates having lower hardness. Copyright © 2021 by ASTM International

Microstructural Features and Mechanical Integrity of Wire Arc Additive Manufactured SS321/Inconel 625 Functionally Gradient Material

The additively fabricated functionally gradient structures can be a potential replacement for conventionally manufactured structures via fusion welding techniques. A SS321/Inconel 625 functionally gradient material was processed by wire arc additive manufacturing (WAAM) process. The WAAM-formed SS321 comprises of equiaxed and columnar structures, while the Inconel 625 consists of dendritic structures. It can be concluded that a very narrow interface was formed between the additively manufactured SS321/Inconel 625 FGM without forming cracks or fissures. Energy-dispersive x-ray spectroscopy (EDS) element maps show a smooth transition of elements at the interface without much segregation while EDS point scan confirmed the presence of laves phase. The electron backscatter diffraction results at the interface region revealed continuous crystallographic growth with large elongated grains in the [removed] orientation. Tensile properties were better for SS321 and comparable for Inconel 625 than the wrought alloys, while the interface FGM sample failed on the SS321 side. The micro-hardness steadily changed from 226-195 HV and 272-236 HV in SS321 and Inconel 625, respectively. The WAAM process demonstrates that successful FGM components can be fabricated with multi-material and controlled properties. © 2021, ASM International

Wire arc additive manufacturing of functionally graded material with SS 316L and IN625: Microstructural and mechanical perspectives

In the present study, functionally graded material (FGM) of Austenitic Stainless Steel-SS 316L and Nickel-based superalloy-Inconel 625 (IN625) was manufactured via Gas Metal Arc Welding (GMAW) based Wire Arc Additive Manufacturing (WAAM). WAAM processed FGM was well-formed without any defects and solidification cracking was not observed at the bi-metallic interface (IF) region. Microstructural features show a sharp transition at the IF with a discontinued dendritic structure. Energy-dispersive X-ray spectroscopy (EDS) examination confirmed the fine dissolution of elements at the IF and no major difference in the composition was observed. Electron Backscatter Diffraction (EBSD) maps confirmed that the grains are dominantly columnar while the IF revealed the smooth crystallographic growth along with large elongated dendrites in thedirection. The microstructure was mainly austenitic in the SS 316L layers with a lower fraction of ferrite while precipitates were noticed in the IN625 layers within the austenitic matrix. Yield strength (YS) and tensile strength (UTS) of SS 316L and IN625 were comparable with wrought ones. All the IF samples at 90° failed in the SS 316L region because of the lower UTS in comparison to IN625 and the mode of fracture was ductile. Microhardness measurements depicted the gradual change of hardness along the building direction. The present work highlights the potential of WAAM to fabricate FGM with required properties and is a viable manufacturing alternative to the traditional manufacturing techniques for producingFGM's. © 2022 CIR