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The primary objective of this study is to investigate the microstructural, mechanical, and wear behaviour of AZ31/TiC surface composites fabricated through friction stir processing (FSP). TiC particles are reinforced onto the surface of AZ31 magnesium alloy to enhance its mechanical properties for demanding industrial applications. The FSP technique is employed to achieve a uniform dispersion of TiC particles and grain refinement in the surface composite. Microstructural characterization, mechanical testing (hardness and tensile strength), and wear behaviour evaluation under different operating conditions are performed. Response surface methodology (RSM) is utilized to optimize the wear rate by considering the effects of process parameters. The results reveal a significant improvement in hardness (41.3%) and tensile strength (39.1%) of the FSP-TiC composite compared to the base alloy, attributed to the refined grain structure (6–10 μm) and uniform distribution of TiC particles. The proposed regression model accurately predicts the wear rate, with a confirmation test validating an error percentage within ± 4%. Worn surface analysis elucidates the wear mechanisms, such as shallow grooves, delamination, and oxide layer formation, influenced by the applied load, sliding distance, and sliding velocity. The enhanced mechanical properties and wear resistance are attributed to the synergistic effects of grain refinement, particle-accelerated nucleation, the barrier effect of TiC particles, and improved interfacial bonding achieved through FSP. The optimized FSP-TiC composites exhibit potential for applications in industries demanding high strength, hardness, and wear resistance. [ABSTRACT FROM AUTHOR]

The present study examined the effect of tool pin profile on the microstructure and mechanical properties of AA2219-T62/Incoloy 800 joints produced using FSW at a fixed rotational speed of 500 rpm. The developed weld joints were studied for microstructure using an optical microscope, electron backscattered diffraction, a scanning electron microscope, X-ray diffraction, and transmission electron microscope. The microstructural results revealed significant grain refinement in the weld zone, X-ray diffraction, and transmission electron microscope results revealed the presence of the Fe3Al phase. Weld joints produced with a tungsten carbide tool with a cylindrical (10°) taper have a maximum hardness of 130 HV and a tensile strength of 320 MPa. Weld joints produced with other tool profiles resulted in lower tensile strength owing to the presence of defects similar to voids, surface tunnels, excessive flash, and end hole defects formed at the interface of AA2219-T62/Incoloy 800 joints. [ABSTRACT FROM AUTHOR]

Wireless sensor networks occupy a prominent role in industrial as well as scientific applications. Lifetime enhancement and coverage are the major factors considered while designing the network. Various research models are evolved by considering the scheduling and routing process to solve the network lifetime issues. However, coverage and connectivity is another important factor that affects the lifetime of the remaining nodes. When a large number of sensors are deployed randomly, scheduling is preferred to enhance the network lifetime, but it leads to coverage issues. Other than scheduling, node damage, battery exhaustion, software and hardware failures might lead to coverage issues. Preserving the network connectivity while maximizing the network coverage is a crucial task in wireless sensor networks. To preserve the network connectivity and improve the wireless sensor networks coverage this research work presents a hybrid deep learning approach using a deep neural network and reinforcement learning algorithm. The Proposed model is experimentally verified and compared with conventional deep neural network and reinforcement learning algorithms to demonstrate the better balancing characteristics between network coverage and lifetime. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "A study on microstructural, mechanical properties, and optimization of wear behavior of friction stir processed AZ31/TiC composites using response surface methodology" published in Scientific Reports. The correction addresses an error in Reference 20 of the original article, providing the correct information for the reference. The authors of the article are T. Satish Kumar, R. Raghu, G. Suganya Priyadharshini, Robert Čep, and Kanak Kalita. [Extracted from the article]

The present study aims to investigate the microstructure and mechanical properties of the A356 aluminum metal matrix composite reinforced with Y2O3 particles. The composite is synthesized by adding 1 and 2 vol.% of reinforcement via stir casting assisted by ultrasonic treatment (UT). Microstructural contemplates show improvement in the dispersion of nano Y2O3 particles and a decrease in the porosity level due to the ultrasound aided synthesis. The UT refines the size of the Y2O3 particles as well as helps to improve their dispersion. The secondary dendrite arm spacing of 2 vol.% Y2O3 reinforced samples with 5 min UT are found to be significantly reduced to 12 μm as compared to that of the as-cast A356 alloy. The addition of 2 vol.% of nanoY2O3 has significantly improved the hardness of the A356 alloy from 60 HV to 108 HV. A considerable increment in the YS and TS of the A356 alloy is observed with the increase in the amount of Y2O3 and found to further improve with UT. However, minimal reduction in ductility is observed with the addition of Y2O3 as well as ultrasonic treatment. [ABSTRACT FROM AUTHOR]

Geochemical and mineralogical studies were carried out on the sandstones of the Eocene Kopili Formation, Shillong Plateau to evaluate paleo-weathering, provenance and tectonic setting. The study area is located on the bank of the Lubha River along the Badarpur-Jowai road section. The Kopili Formation is represented by a sequence of alternation of shales and sandstones. The sandstone beds are usually thin, fine grained, ferruginous and mostly parallel laminated. The thickness of the sandstone beds increases towards the top with decreasing numbers of shale beds. Petrographically the sandstones are dominated by monocrystalline and polycrystalline quartz followed by feldspar, mica and rock fragments. The matrix content does not exceed 15% and hence the sandstones can be classified as arenite. The Kopili sandstones are classified as quartz arenite to sublitharenite, and arkose to sublitharenite based on their petrographic and geochemical parameters respectively. Arenitic composition and high SiO2/Al2O3 ratio indicate that the Kopili sandstones are highly mature. The weathering indices mostly indicate low to moderate (except 49D sample) degree of chemical weathering under arid to semi humid climatic conditions. The major and trace element-based diagrams and their ratios indicate that the Kopili sandstone received sediments from felsic dominated source with minor contribution from basic source rocks and are deposited in tectonically passive margin setting. [ABSTRACT FROM AUTHOR]

The effect of thermal treatment on microstructure and tribological behavior of Al-7Si/ZrSiO4 reinforced composites has been investigated. Composites with 5, 10 and 15 vol.% of ZrSiO4 particles were produced using stir casting process. Produced composite samples were then further subjected to T6 heat-treatment by subjecting the cast samples for solution treatment for 4 h at 540 °C followed quenching in water and artificial ageing at 170 °C for 5 h. Microstructure of the composite samples revealed uniform distribution of ZrSiO4 particles. Hardness of the T6 thermal treated samples was found to be superior to that of Al-7Si alloy and hardness of the composite samples increased with increase in wt.% of ZrSiO4 particles. Non heat treated alloy and composite reinforced with 15 wt% of ZrSiO4 possessed a maximum hardness of 68 BHN and 110 BHN respectively. Whereas T6 heat treated Al-7Si alloy and composite reinforced with 15 wt% of ZrSiO4 exhibited a maximum hardness of 84 BHN and 146 BHN respectively. T6 treated composites exhibited superior resistance to wear, when compared to the base alloy. As cast Al-7Si alloy exhibited maximum wear rate of 14.3 × 10−3 mm3/m, where as non heat treated 15 wt.% ZrSiO4 reinforced composites exhibited a wear rate of 7.6 × 10−3 mm3/m and wear rate was found to further reduce to 4.0 × 10−3 mm3/m by T6 treatment. SEM images of the wear tested samples showed the adhesive wear and abrasive wear as the dominant wear mechanisms. [ABSTRACT FROM AUTHOR]

Dry sliding wear behaviour of Al–4Mg alloy and Al–4Mg alloy/MgAl2O4 in situ composites was examined under normal loads of 10–30 N at sliding speeds of 1, 3, 5 and 7 m/s and sliding distance of 1500 m using a pin-on-disc apparatus. Al–4Mg alloy with different wt% (1, 2 and 3) of MgAl2O4 in situ composites was synthesized via ultrasonic cavitation by the addition of H3BO3 powders. Unreinforced alloy and composites were characterized to conclude the role of MgAl2O4 in modifying the wear behaviour of the composite. Worn-out samples and wear debris were examined by scanning electron microscopy and X-ray diffraction in order to obtain the major wear mechanisms of the developed composites. The addition of MgAl2O4 significantly reduces the wear rate of Al–4Mg alloy at higher loads. The operating wear mechanisms observed were delamination, oxidation, abrasion, adhesive, thermal softening and plastic deformation modes. [ABSTRACT FROM AUTHOR]

In the present study, effect of ZrC vol.% on mechanical properties of AA6061 metal matrix composites (MMCs) produced via stir casting technique was investigated. The vol.% of ZrC particles was varied as 5,10 and 15. The composites were characterized for its microstructure and mechanical properties and their relationships were obtained. The scanning electron microscope (SEM) images revealed uniform distribution and good bonding between the AA6061 alloy and the ZrC particles. The mechanical properties of the AA6061 alloy was found to significantly improve with the addition of ZrC particles from 5 to 15 vol.%, the hardness increased from 32 to 68 HV, yield strength increased from 50 to 86 MPa and the ultimate tensile strength increased from 118 to 165 MPa. However, the % of elongation of the composite samples decreased with 15 vol.% addition of ZrC particles. Sliding wear behaviour of the composites was investigated using a pin-on-disc wear tester at a load of 9.8 N and addition of ZrC particles was significantly found to reduce the wear rate of AA6061 alloy. [ABSTRACT FROM AUTHOR]

The Eocene coal deposits of west Daranggiri coalfield of Meghalaya is hosted in the Tura Formation. The coals are perhydrous in composition, rich in organic matters and poor in mineral content. The organic matters are dominantly represented by Type III kerogens contributed by terrestrial plants. Petrographic analysis confirms dominance of vitrinite with subordinate amounts of liptinite and inertinite. Maturity parameters like vitrinite reflectance, Rock-Eval Tmax, volatile matter content etc. indicate low thermal maturity of the coal within lignite to subbituminous rank. The coals are immature to act as petroleum source rock despite having high-quality organic matters. However, perhydrous nature of the organic matters and significant amount of liptinite macerals suggest that despite low thermal maturity, the coals might have some capacity to generate liquid hydrocarbon. High liptinite and perhydrous vitrinite contents of the coal may result in suppression of vitrinite reflectance, thus, underestimation of maturity. Presence of exsudatinite in the coal also points to generation of some liquid hydrocarbon. The coal deposits possess excellent potential for hydrogenation industry. The coals are characterized by very high rate of conversion from coal to oil and high oil yield. Indices of facies critical maceral association indicate the origin of the coal in wet swamps under mildly oxic to the anoxic environment with moist hydrodynamic condition. The high sulphur content of the coal, association of marine palynological assemblage and presence of limestone beds at the top of the Tura Formation point to nearshore environment of deposition. [ABSTRACT FROM AUTHOR]