Boralyn (Al/B4C) composite material is produced chiey of boron carbide and aluminum. Boron Carbide is an important material for the nuclear industry due to high neutron absorption cross-section. This composite is used as shielding materials to absorb neutrons in the nuclear reactors and control road materials. In this study we investigated Al/B4C composites against gamma radiation. For that purpose, 5 wt.%, 10 wt.%, 15 wt.% and 20 wt.% reinforcement content were investigated. Cs-137 gamma radioisotope source which has 662 keV gamma energy photons were used. For each material, linear and mass attenuation coecients were calculated. Theoretical mass attenuation coecients were calculated from XCOM computer code. The theoretical results were compared with experimental results. The results were showed that increasing the amount of Boron Carbide compound content of boralyn composite material decrease the linear and mass attenuation coecient of materials

Hexagonal boron nitride (h-BN) based ceramics have been fabricated by hot-pressing in a nitrogen atmosphere at 1900°C for 60 min. under a pressure of 50 MPa with B2O3 as sintering additive. The phase composition was confirmed by XRD. The microstructural properties of h-BN powders and hot-pressed surfaces were evaluated by SEM-EDS analysis. The formation of the secondary phase was also investigated with particular interest on grain boundaries. The sintered densities were also determined by Archimedes’ method. The maximum relative density was obtained to be about 92 %. The effect of the existence of boron oxide on the boron nitride grain growth behaviour was discussed on the basis of microstructural features.

With the addition of Al and/or Cu into the NdFeB based magnet, the soft free iron phase was not observed in the cast alloys while it exists in the microstructure of the undoped NdFeB ingots. For the undoped sample, free iron disappeared after hot deformation process. Grain orientation is not good and there are deviations in the growth direction of the lamellar grains which are not perpendicular to the pressing direction. On the other hand, there is a striking change that the intergranular chemistry of Al added ingot separated into Nd-rich phase and a ternary FeNdAl composition most probably formed at the pressing temperature of 750• C. The highest remanent magnetization of 7.47 kG obtained for this sample, it might be due to the hard magnetic properties of this ternary composition. For the AlCu added sample, the high Hc and Br values of 7.71 kOe and 7.33 kG, respectively, can be attributed to the homogeneous distribution of the intergranular composition and good orientation of the magnetic grains by hot deformation process.

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Rice husk is a potentially useful source material for the production of silicon nitride, silicon carbide or a mixture of both. Pyrolysis of rice husk yields an intimate and homogeneous mixture of carbon and silica which is highly desirable for a good carbonitrothermic or carbothermic reduction process. The formation of S13N4 occurs on heating the pyrolysed rice husk to 1400°C under nitrogen flow and SiC forms in the presence of excess carbon at temperatures above 1450°C. SEM and XRD results show that the morphology of the nitride product is influenced by the reaction temperature and the presence of additives.

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In this study, boron carbide thin films were deposited on AISI M2 grade high-speed steel substrates by plasma-enhanced DC magnetron sputtering of an 'in-house' produced boron carbide target material. Tribological properties of the coatings have been evaluated by a 'pin-on-disc' tribometer. Wear tracks on boron carbide thin films were investigated by scanning electron microscopy-energy dispersive spectroscopy, electron probe microanalysis and secondary ion mass spectrometry (SIMS) elemental ion imaging. The results of analyses provided information about the reliability of the SIMS ion imaging compared to the other investigation techniques on nano-layers and nano-sized thin films.