Production of al based cermet composite reinforced with boron carbide and caracterization

Boron carbide is the most rigid material after diamond and cubic boron nitride. In addition, good resistance against many chemical reactions and also the low density its important features. Boron carbide which content nearly 80% boron having effective to absorb neutrons and has economic use due to high melting point, good chemical and physical stability. With these features there are important areas like making cutting instruments, creating a special tip, and making armor material. . In addition, one of the most high specific strength ceramics have been obtained by using boron carbide and mechanical properties can be developed without enhancing the total weight.In this study, boron carbide has been synthesized using boron and carbon elements. Ceramic-metallic composite material produced and tested from this material. The study established two phases. At the first stage, carbon and boron elements, which 4 different ratio, are produced inert atmosphere with mechanochemical reaction. Products are sintered at 1550°C fort he formation of boron carbide crystals. Products are analysed with FT-IR and XRD respectively for examinating the peak intensities. According to these results B/C ratio are determined. Result of TGA-DTA analysis which occured 20 ml / min nitrogen-argon gas flow, stability of boron carbide at the high temparatures are observed. In addition, there is not observedany degradation at high temparatures. The second phase of experiments, 5 different rates of Al-B4C composites prepared by making a uniform ball mill, pressed into the plate 400 MPa pressure. After composites pressed at 600°C for 1 hour at atmospheric environment, their hardness measurements were made. Composite hardness are increased to %50 reinforced composite but hardness started to decrease more than %50 reinforced composite. After the decision of contribution, the effect of sintering time and sintering atmosphere on the composite hardness were examinated and density of the material were calculated. At the same time in the distribution of matrix particles were examined by SEM and EDS analysis.At the end of the study, the sample which was sintered during 120 min in argon atmosphere, B/C mole ratio is 4/1 and %50 reinforced composite are choosen optimum parameters. Its vickers hardness is 418 Hv and density is 2,48 g/cm3. SEM-EDS analysis shows a uniform distribution also approach nearly %95 to theoretical density shows that the study supplies important contribution to our country.