Investigation into Hypo-eutectic, Eutectic, and Hyper-eutectic Compositions of Al-xCu Alloys Produced by the Powder Metallurgy Method

In this study, characteristic changes of Al-xCu alloys produced by the powder metallurgy method in critical transformation regions of binary Al-Cu phase diagram were investigated. In this framework, Al-xCu alloys with a content of 5-15-25-33-45 wt.% Cu, which would enable the formation of hypo-eutectic, eutectic, and hyper-eutectic regions, were prepared. The prepared powders were converted into a green compact form by compressing at a 600 MPa pressure ratio. The obtained green samples were placed in the sintering die and sintered in accordance with the critical transformation temperatures determined in the binary phase diagram. Once the sintering process was completed, the samples in the hot die were compressed at a pressure ratio of 5 MPa and cooled with air. As a result of the microstructural examinations on the produced samples, it was observed that partial liquefaction occurred in the Cu particles due to the increase in the Cu content of the alloy and the amount of CuAl2 intermetallic compound increased accordingly. In this context, as the Cu content of Al-xCu alloys increased, the microhardness and wear resistance values increased; however, the ductility, compressive strength and electrical conductivity values decreased.