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Abstract- Unique properties of boron carbide (B4C) such as high hardness, low density, and comprehensive area for Neutron attraction, have turned this material into a very suitable candidate for many industrial applications such as nuclear facilities and light armored plates. According to inappropriate sinter ability of boron carbide, phenolic resin was utilized as sintered help for this ceramic. Different free additive samples of B4C with 5wt% phenolic resin were prepared and sintered at 2200°C. Then their physical and mechanical properties were investigated. Results show that the relative density of samples including 5wt% phenolic resin is equal to %95 and for samples without additive is equal to %82 of theoretical density. Furthermore, it can be seen an improvement in mechanical properties in comparison of free additives samples; so that the flexural strength from 264 to 318MPa, the modulus of elasticity from 445 to 465GPa, Vickers hardness from 3020 to 3150GPa and fracture toughness from 2.6 to 4.2MPa.m1/2 will be improved.

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In this article the effect of hot rolling process on properties and microstructure of Al-B4C composite is investigated. To produce the composite samples, 3 vol.% B4C particles with 300 nm average grain size added to melted Al-356 alloy. Rolling process was done at 350 °C on vortex samples that is made after 15 minutes mixing at 850 °C. Porosimetry, hardness and tensile strength tests were carried out to investigate the physical and mechanical properties of composite samples. Microstructures of the samples were also investigated by using scanning electron microscopy. The results indicate lowering the amount of porosity, increasing hardness and increasing tensile strength of rolling composites. The amount of porosity before rolling process was 2.05% that is decreased to 0.35% after rolling process. Tensile strength and hardness of composites before and after rolling process achieved 178 MPa and 293 MPa and 62 HBN and 101 HBN respectively. Also hot rolling process caused to more ductile fracture of composites that is produced by vortex. Tensile strength and hardness of composites before and after rolling process achieved 178 MPa and 293 MPa and 62 HBN and 101 HBN respectively. Also hot rolling process caused to more ductile fracture of composites that is produced by vortex.