engleski

Properties of continuously casted Cu-Al alloy

In this work are shown properties of continuously casted Cu – 9.1Al alloy before and after heat treatment. The continuously cast cylindrical bar with 8 mm diameter was produced using the device for the vertical continuous casting which is connected with the vacuum induction furnace. Heat treatment was consisted of annealing at 900 °C/30 minutes and water quenching. Microstructural analysis was performed by optical microscopy (OM), scanning electron microscopy (SEM) equipped by device for energy dispersive spectroscopy (EDS) and using differential scanning calorimeter (DSC). Also, hardness and mechanical properties were measured. EDS analysis confirmed that as-cast state of Cu – 9.1Al alloy is successfully done and alloy with homogeneous composition was produced. Optical and scanning electron microscopy showed existence of dual-phase α+β microstructure, which keeps after heat treatment but with certain sporadic changes of α - phase shape. DSC analysis on all samples presented one endothermic change of the heat flow during the heating, which probably represents α→β transformation and one exothermic change of the heat flow during the cooling which probably represents β→α transformation. The effect of heat treatment on the hardness and yield strength values is insignificant, while the tensile strength decreases with annealing.

Cu-Al alloy ; heat treatment ; microstructure ; mechanical properties ; hardness

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