Investigation of tribological behavior of traditional and waste reinforced Al6061 metal matrix composites

In this study Al6061 alloy as matrix material, SiC and Al2O3 ceramics which are frequently used in automotive industry as traditional reinforcements and blast furnace slag as waste reinforcement material. Blast furnace slag is a side product that is turned on during iron production in blast furnaces in iron and steel plants. Iron ore, limestone and coke are used as raw materials in demi production. These processed materials, which have reached the high temperature of 1600˚C in the high-temperature furnace, decompose. At the bottom of the pig iron furnace, where the density is higher than that of the high-temperature-ending melts, the less dense slag is collected at the top of the furnace. Molten slag and pig iron are separately evacuated. The collected slags were converted into powder by ball mill and after separation according to their powder sizes, those with a size of 22-59μm powder were used as reinforcement elements in metal matrix composite production. SiC and Al2O3 ceramics with a powder size of 22-59μm were also supplied from the market. Dual and triple hybrid composites were produced with single composites by using traditional and waste reinforcement materials. onolithic composites and hybrid composites were produced using the two-stage mixing casting method, which is liquid state production methods. In this method, the Al6061 alloy is first heated to 700ºC, then the alloy temperature is lowered to 600ºC and the alloy, which is semi-solid at this temperature, is preheated to 250ºC and added by hand. The alloy is then superheated and the temperature of the alloy is increased to 800 ° C and at this temperature 250deg / min. The alloy was mechanically mixed for 10 minutes at speed. Nitrogen gas was used as the inert gas during the mixing process and the oxygen in the environment was removed. Composites were then produced by casting metal molds with a length of 300 mm and a diameter of 14 mm. The microstructures of the produced composites were investigated by scanning electron microscopy. The porosity values obtained from EDS analyzes were calculated with Archimedes principle and the hardnesses were determined by Brinell hardness measurement method. For the fatigue strengths of the composites produced, the number of cycles was measured up to the breaking of the specimens at 9 different stress values using the rotary curved fatigue device. The microstructures of the produced composites were investigated by scanning electron microscopy. The porosity values obtained from EDS analyzes were calculated with Archimedes principle and the hardnesses were determined by Brinell hardness measurement method. For the fatigue strengths of the composites produced, the number of cycles was measured up to the breaking of the specimens at 9 different stress values using the rotary curved fatigue device. The porosity amounts and Brinell hardness values were determined by producing 3 pieces from each sample. In this way, the reliability of the measurements is increased. In the porosity measurements, porosity was higher in SiC and Al2O3 than in SiC and Al2O3 reinforcements in blast furnace sloupe reinforced single composite materials. It has been observed that as the weight ratio of the reinforcing material added to the matrix increases, the porosity value increases with it. It has been determined that the hardness of the composites increases with the increase of the weight ratio of the composites added in the hardness tests and the blast furnace slag powder is almost as effective as SiC and Al2O3 in increasing the hardness of the composites. The blast furnace slag we use as reinforcement element in the production of double and triple hybrid composites with monocomponent has increased the fatigue strength of Al6061 up to 11% by weight of reinforcement.