Production of composite based on Ti-Al-B by reduction combustion synthesis technique

Materials used in the defense industry and aerospace industry is generally defined as the Advanced Technology Materials, there are composite TiB2-Al2O3 among these materials. Combustion synthesis is a simple, economical and rapid method fort he producing of some ceramics, composites, intermetalic and functionally graded materials. Combustion synthesis process is syntehesising technology for inorganic materials using the exothermic reaction heat between reactant powders and becomes self-sustaining to yield the final product. By utilizing the process, it is expected that the near net shape compound can be obtained from the elemental powder. The cost of by production reduction combustion synthesis technique based on the conventional combustion synthesis by combining with the thermite is reduced.The aim of this study is to produce TiB2-Al2O3 composite by reduction combustion synthesis method. TiO2, B2O3, Al2O3, and Al as starting materials were used to produce TiB2-Al2O3 composite by Aluminothermic reduction. The production of the in-situ composite was carried out in a electrical resistance furnace in open air under 150 MPa uniaxial pressure at 1050 oC, 1100 oC and 1200 oC for 2 and 4 hour using mixture powder. Oxidation properties of the sample which were produced under 150 MPa uniaxial pressure at 1200 oC for 4 hour were invastigated at 600, 800 and 1000 oC for 4, 16, 32 and 64 hour.Optical microscopy, scanning electron microscopy and X-ray diffraction analysis were used to characterize the produced and oxidized samples. The XRD analysis shown that the produced samples consist of TiB2 and Al2O3 phases. The relative density of the produced samples (called doped (10 Al2O3 %) and undoped materials) measured by sensitive balance 0.001 g using the Archimedes? principle and the relative density of the samples were determined as %93.1 and %94.2 respectively. The microhardness of the samples was approximately 1832.25± 496 HV0.1. The oxidation studies at 800 oC shown that the materials doped 10 Al2O3 % are more stable against oxidation than others. The distribution of alloying elements within the samples was determined by energy-dispersive X-ray spectroscopy.