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This work aims to convert the bio-waste material into a fruitful product. This prepared product can be a solution for environmentally hazardous materials like polymer bags and plastic food wrappers. The prepared material is composed of bio-waste pomegranate peel powder and environmentally friendly polyvinyl alcohol. To extend its functionality in food wrappers, the silver nitrate solution is incorporated. The prepared samples were undergone various performance studies. The prepared films show high thermal with standing capacity and tensile properties and especially show better results in biodegradability as well as antibacterial activity. Among the fabricated films, the 5 mM AgNO3-fabricated film shows that the thermal stability up to 331 °C also possesses higher tensile strength of 25.7 MPa. These results make the possibilities of the fabricated PP/PVA/5 mM AgNPs film as an alternative for conventionally used plastic-based food wrappers.

The work aims to probe the chances of utilizing the waste of pomegranate peel powder as a filler material alongside the polymer matrix. PVA is used as a polymer matrix in this study and the improvisation of its properties are the main objective by utilizing the pomegranate peel powder. By solution casting method, PVA/PP biocomposite films were prepared with varying weight % (0%, 5%, 10%, 15%, and 20%) of pomegranate peel powder and are examined with FTIR, XRD, morphological studies, thermal analysis, tensile property, antibacterial test, and degradation test. The biodegradable films’ tensile strength was discovered to be 18.5 MPa, a 35% increase over films devoid of essential oil. The use of essential oil improved the thermal stability as well; the beginning degradation temperature increased by 40% to 210°C. Additionally, antimicrobial tests showed a 92% decrease in bacterial growth, demonstrating the essential oil’s effectiveness as an antibacterial agent. In order to evaluate the barrier qualities of the films, water vapor permeability was tested. It was discovered that the water vapor transfer rate was 2.3 g/m2/day, demonstrating remarkable resistance to moisture permeability. The aforementioned tests indicate that the use of pomegranate peel powder and PVA in biocomposite films results in improved biodegradation, as well as antibacterial activity, and that can be utilized in various eco-friendly applications. In the same way, they show improved tensile as well as thermal properties which suggest the utilization as packaging materials.

Purpose: The acousto-ultrasonic approach is used for propagating stress waves through different configurations of CORTEN steel specimens. The propagated waves are recorded and analysed by piezoelectric sensors. The purpose of the study is to study the characteristics of the CORTEN steel by analysing the propagated waves. Design/methodology/approach: To investigate the attenuation in acoustic wave propagation due to the corrosion formation in CORTEN steel specimens and to train a neural network model to classify the attenuated acoustic waves automatically. Findings: Due to the corrosion formation in CORTEN steel specimens, attenuation is observed in amplitude, energy, counts and duration of the propagated waves. When the waves are analysed in their time-frequency characteristics, attenuation is observed in their frequency and spectral energy. Originality/value: The corrosion formation in CORTEN steel can automatically be analysed by using the acousto-ultrasonic approach and the trained deep learning neural network.

The effects of using recycled AlSi10Mg aluminium alloy powders on the mechanical properties and the corrosion-resistance behaviour of the components manufactured via selective laser melting (SLM) were analysed. The microstructural results show that the utilisation of recycled powder causes coarsening of interdendritic Si-network, especially along the melt pool boundaries of the SLM specimens. The corrosion resistance of the samples was evaluated by means of neutral salt spray (NSS) tests for 1000 h and mass loss measurements. The corrosion behaviour, in terms of surface roughness, density and porosity, however, remains almost the same between the samples produced by virgin and recycled powder. In addition to this, a passive NDE tool has been used to investigate and study the impact of powders on the corrosion performance of the alloy: Acoustic Emission (AE) technique. SEM observations allowed to highlight the morphological differences in the surface of the test specimens induced by the exposure condition. Thus, it was possible to correlate the AE results to corrosion mechanisms activated on the surfaces of the test specimen. A good correlation between the corrosion-resistance behaviour and the AE test results were obtained. Finally, the mechanical properties before and at the end of the accelerated corrosion were evaluated according to the yield strength, tensile strength, and elongation at breakage. The results showed comparable mechanical properties for the samples produced using both virgin and recycled powders. Besides, no notable influence of the exposure to corrosive environment on the mechanical performance was observed.

Fiber metal laminates (FMLs) provide lucrative solutions for lightweight commercial aircrafts. They are a class of hybrid composites made from interlaced layers of thin metals and fiber-reinforced adhesives. The present investigation deals with the effects of hybridization and stacking sequence of aluminum sheets (A), jute (J) and Kevlar (K) fibers on the flexural, impact, hardness and tensile properties. Three distinct configurations A/K/A/K/A/K/A (I), A/J/A/K/A/J/A (II) and A/K/J/A/J/K/A (III) of FMLs have been chosen and designed for evaluation of their mechanical attributes. Comparative analysis shows that configuration A/K/J/A/J/K/A (III) offers superior results for flexural, impact, shore D hardness and tensile properties due to hybridization and appropriate stacking sequence with their maximum values as 495 N, 10.4 J, 85.4 and 325.6 MPa, respectively. Outer Kevlar layers supported by the subsequent jute fiber layers enable the configuration A/ K/J/A/J/K/A (III) to resist better when subjected to high mechanical load. Moreover, the microstructural analysis revealed that the jute fibers make a stronger bond with aluminum and Kevlar fibers which prevents FMLs from delamination and early failure.

In this research work, four groups of selective laser melted specimens were built from AlSi10Mg-0403 powder. Each group represents the direction with respect to the bed in which the specimens are built (X, Y, Zand 45° orientation). The mechanical properties of the specimens are characterized in terms of yield strength, ultimate tensile strength, Young’s modulus and elongation at break. In addition to that, the acoustic emission (AE) during the testing was monitored using wide-band high-accuracy piezoelectric sensors. The AE results were related to the mechanical characteristics of the specimens in terms of the acoustic parameter-based data, the peak amplitude, cumulative energy and count rate. The mechanical results show that the specimens built along the zdirection have relatively lower strength and it can be attributed to the borderline porosity formed during the SLM process. The acoustic results can identify the critical points of failure under loading. The AE technique proves to be a powerful tool in characterizing the mechanical property and can unveil the concealed information which cannot be identified directly from the mechanical results.