Effect of 0.5 mass% Cu Addition on Ductility and Magnetic Properties of Fe-6. 5Si Alloy

The effect of adding 0.5 mass% Cu on ductility and magnetic properties of Fe-6. 5Si (mass%) alloy was investigated. The alloys with and without 0.5 mass% Cu addition were warm rolled into thin sheets of thickness no more than 0.3 mm at temperature below 600 °C. It was found that the alloy with 0.5 mass% Cu addition was more easily warm rolled than Cu-free alloy. Tensile tests were carried out to further investigate this phenomenon, which confirmed that the ductility of the alloy with 0.5 mass% Cu addition was significantly higher than that of Cu-free alloy at 550 °C. Based on the results of transmission electron microscopy analysis, the ductility increase of the alloy with 0.5 mass% Cu addition was attributed to the effect of Cu on the promotion of dynamic recovery and suppression of long-range order in the alloy during warm rolling process. It was also observed that the iron loss was lower and inductance was higher for the alloy with 0.5 mass% Cu addition. Thus, it can be concluded that adding a suitably small amount of Cu would not only increase the ductility of Fe-6. 5Si alloy at warm rolling temperatures but also improve its magnetic properties.