The resistivity evolution with temperature of 7050 aluminium alloy by different casting methods

The resistivity-temperature curve of 7050 aluminium alloy prepared by different casting methods (DC and LFEC) has been measured with D.C. four-probe method. By analysing the curve, it was found that a change occurred to the slope at 250℃ when the samples were heated, and the resistivity of LFEC sample changed with temperature more quickly than that of DC. Both the solidus and liquidus temperatures of LFEC samples were higher than those of DC samples during the process of temperature rise from room temperature to 900℃. However, the resistivity of DC samples increased remarkably when the temperature was kept at 900℃ and before it was decreased to 600℃. With the help of microstructure observation, the characteristics and phenomenon of the resistivity evolution with temperature were studied.