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In this work the effect of stacking sequence of Carbon (C)/Glass (G) fibers and halloysites addition (1, 3 and 5 wt.%) on the mechanical and thermal properties of the hybrid composites were explored. The composite laminates were prepared by using Vacuum Assisted Resin Infusion Technique (VARIT). The outcomes disclosed that the hybrid composites having sequence of C2G3C2 (2-Carbon/3-Glass/2-Carbon layers) showed better overall properties. Moreover, the addition of halloysites enhanced the mechanical and thermal properties of the C2G3C2 hybrid composites. In particular, the hybrid composites added with 3 wt.% of halloysites showed higher overall properties among the other hybrid composites investigated. Finally, the morphological analysis was performed on the fractured surface of mechanical tested composites to study the failure mechanisms occurred. Based on the obtained results it can be concluded that the C2G3C2 hybrid composites added with 3 wt.% of halloysite could be a suitable alternative light weight material for automobile, aerospace and building structures.

The objective of the present work is to investigate the mechanical properties of the dual phase (DP) steels produced by the intermediate quenching (IQ) technique. To produce the ferrite-martensite microstructure in the dual phase (DP) steel, low carbon micro alloyed steel is intercritically heat treated followed by short intercritical annealing and intermediate quenching using various intercritical temperatures. By varying the intercritical temperature (740, 760, 780, 800, 820 °C) different volume fraction of the ferrite and martensite phases of DP steel samples are produced. These series of dual phase (DP) steel samples were further analyzed through scanning electron and optical microscopy. The experimental investigations have been carried out to find the mechanical properties as per the ASTM testing standards. From the outcomes it is observed that DP780 steel have excellent tensile strength, better hardness and toughness which may be due to the fine distribution and equal volume fraction of ferrite and martensite phases. The enhancement in the mechanical properties of dual phase steel was the effect of intermediate quenching technique. Equal volume fraction of ferrite and martensite phases obtained, at temperature of 780 °C, converted low carbon micro alloyed steel into dual phase steel and also improves its mechanical properties.

Hybrid composites with multiple reinforcements of high strength are very popular for many engineering applications, especially for impact resistance. In the present work, we report the development of the glasscarbon/epoxy hybrid composites using hand lay technique and investigate its low velocity impact response. Low velocity impact tests were performed on the hybrid composites of two different thicknesses 2 mm and 4 mm to study the impact resistance of hybrid composites with respect to impact energy and impact velocity. In addition to this, defect was embedded in the hybrid composite and its effect on the impact response was studied and compared with the hybird composites without having any defect. The study revealed that the presence of defect in hybrid composite has significant effect on the energy absorbed when compared to that of composite without defect.

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