Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced co mposites have increased and opened up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However, the main d isadvantages of natural fibers in co mposites are the poor co mpatibility between fiber and matrix and the relative high mo isture sorption. Therefore, chemical treat ments are considered in modify ing the fiber surface properties. In this study, Sisal fibers were modified using alkali and benzoyl pero xide solution of different concentration for different time intervals. Morphological changes, thermal stability and crystallinity of fibers were investigated using scanning electron microscope (SEM), TGA and XRD technique. Thermal stability of sisal fibers were decreased on mercerization. Whereas, sisal fibers treated with benzoyl pero xide the enhanced thermal stability. In case of XRD studies, sisal fibers show enhanced crystallin ity.

No abstract

No abstract

Oxidation studies of Co-Cr-Cu-Fe-Ni-Si X=(0,0.3,0.6,0.9) high entropy alloys (HEA) at 600, 700 and 800°C for 30 h are performed in the present work. Isothermal oxidation confirmed that the oxidation resistance of Co-Cr-Cu-Fe-Ni-Si X=(0,0.3,0.6,0.9 ) high entropy alloy increases with Silicon (Si) content up to 0.6%, beyond that it decreases. Oxidation rate kinetics study of all the alloys at the three designated test temperature represented the typical cubic curve. X-ray diffraction (XRD) analysis revealed the evolution of Cu oxide (CuO) along with existing phases in all the HEA samples. Microstructural observation after oxidation test exhibited an increase in oxide formation with the oxidation temperature. To comprehend the kinetics of oxidation more clearly, Arrhenius plots were drawn for all the HEA samples and activation energies are calculated.

No abstract