The grain refining of A206.0 aluminum copper alloys with different inoculants and improving the mechanical properties by applying T6 heat treatment

Aluminum, which is a soft metal in pure form, has a wide range of applications in the industry when it is alloyed with different alloying elements. Aluminum copper alloys are preferred in material design where high mechanical properties stand out. Aluminum alloys have been found to be used in many different sectors due to their properties such as low density, high specific strength, high corrosion resistance, easy forming and improving their mechanical properties. The use of aluminum alloys is increasing in many sectors, especially in automotive, transportation, aerospace, electronics, machinery and manufacturing. The aim of this study is to improve the mechanical properties of aluminum copper alloy by applying T6 heat treatment to the test specimens obtained by casting three different thinner master alloys such as AlSr10, Al-3Ti-1B, Al-5Ti-1B to Al-5% Cu cast aluminum alloy. Al - 5% Cu alloy after entering the grain thinners were cast into the gravity mold. For T6 heat treatment, 4 hours solution at 535oC, quenching at 25oC followed by artificial aging of 3, 6, 9, 12, 15 and 18 hours at 175oC were applied. Brinel hardness measurements, Charpy notch impact tests and tensile tests were performed on T6 heat treated samples. The microstructures of the samples were examined by optical microscope and grain size measurements of the microstructures of the alloys were determined by image analysis method. The internal structures of the alloys were examined by scanning electron microscopy (SEM) from the broken surfaces of the drawn rod samples by point, area and maping analysis. In addition, wear tests were applied to these Al-5 %Cu alloys at 3000 m sliding distance. In order to determine the corrosion resistance of these alloys, 590 hours of immersion corrosion tests were conducted. XRD analyzes were performed to determine the crystallographic characterization of the alloys. The highest tensile strength obtained; Al-5Ti-1B alloy aged at 175oC for 18 hours was obtained as 417 MPa. The highest Brinel hardness value was obtained as 112 HB in the sample which entered Al-5Ti-1B grain refiner and aged at 175oC for 18 hours. The results obtained in this study are also supported by the three-axis Matlab graphic drawings. AlSr10 grain refiners have not been as effective as titanium and boron. Al-5Ti-1B grain refiners were found to be more effective than Al-3Ti-1B in terms of grain size thinning effect of the material. Al-Si alloys have been made on this kind of work before, Al-%5Cu alloys have been focused on this issue since there is not enough work on the alloys. Al-%5Cu casting alloys are produced in the industry, but in practice there are many variable parameters and focus on optimum parameter values. In this study, Al-5Ti-1B grain refining master alloy, which is entered at a rate of 0.6% in grain refining, was found to be the most effective grain refiner. When Al-5Ti-1B grain refining master alloy was added to Al-5 %Cu alloy, the average grain size was obtained as 38 µm after 18 hours aging at 175oC.