Production and characterization of insitu boride reinforced composites based on intermetallic compounds

Combustion synthesis is a synthesis that is prominent in the production of various material groups due to its ease, cheapness and rapid realization. Self-Propagating High Temperature Synthesis, known as Spontaneous Combustion Synthesis, is a frequently preferred method due to its exothermic nature and self-ignition. In this context, this production method is used to obtain advanced technological materials. Intermetallic compounds that operate at higher temperatures and show optimum properties are preferred in the defense, aviation and space industries. Iron aluminide (Fe3Al), nickel aluminide (Ni3Al) and titanium aluminide (Ti3Al) are just a few of the preferred intermetallic compounds. It is desired to eliminate the disadvantages of these compounds by adding advanced technological ceramics such as TiB2 and to expand their areas of use. Within the scope of the thesis, the production of aluminide (Fe₃Al, Ni₃Al, Ti₃Al) matrix and TiB₂ ceramic reinforced metal matrix composites (MMC) by SHS (Self-Progressive High Temperature Synthesis) method was investigated. Fe, Ni, Ti, Al and amorphous B powders were mixed and shaped at initial pressing pressures of 635 MPa and 847 MPa. Microstructure examinations were carried out using optical microscope (OM) and scanning electron microscope (SEM/EDS), phase formations and crystal structures were characterized in detail by X-ray diffractometer (XRD). Hardness measurements were carried out with Vickers microhardness test and mechanical properties of different composites were compared. In addition, oxidation behaviors were evaluated by isothermal oxidation tests performed at 500°C, 900°C and 1000°C. Fe₃Al-TiB₂ and Ni₃Al-TiB₂ composites reached 618 HV and 957 HV hardness values, respectively.