Production of Al6061 matrix sic ain and oltu stone reinforced hybrid composites with powder metallurgy and investigation of their physical and thermal properties

In this thesis study, environmentally friendly and cost-effective hybrid composites with Al6061 matrix, SiC, AlN and powders obtained from easily available Oltu Stone waste were produced by the powder metallurgy method, using powders obtained from Oltu Stone waste as reinforcement elements. Approximately 90% of the waste is generated in Oltu stone until it is extracted from the mine and turned into the final product. Considering both the environmental effects and the cost of disposing of the waste in question, its usability as a reinforcement material in the production of metal matrix composites for reuse has been the focus of this thesis study. In addition, the compatibility of waste Oltu Stone powder with SiC and AlN, which are traditional reinforcement elements, was investigated. Oltu Stones, which were obtained as waste from workshops operating in the field of stone processing in Oltu district of Erzurum province, were pulverized in the ball mill and sieved in the shaking device together with SiC and AlN powders obtained from the market. The powders that passed through the 75µm sieve and did not pass through the 63µm sieve were collected and used as reinforcement elements. The powders of the samples were prepared by weighing them on a precision balance in accordance with the experimental design, and mechanically mixing them for 10 minutes and at a constant speed of 250 rpm. The powders placed in press molds designed and manufactured in 2 different sizes and shapes were pressed in a hydraulic press at 450MPa pressure for 1 minute. Then, composites were produced by sintering at 660ºC for 360 minutes. The microstructures of the produced composites were imaged with a scanning electron microscope and the presence of reinforcements and their homogeneous distribution were determined. The hardness of the composites was determined using the Micro Vickers hardness measurement method, the wear amount was determined using the Pin-On disk method and the thermal conductivity was determined using the Laser Flash technique. It was determined that as the Oltu stone powder increased in the composite, the hardness and thermal conductivity of the composite increased, while the amount of wear decreased.