Effect of Cr addition on the hot deformation behavior and microstructure evolution of Cu-0.8Fe-0.2Mg alloy

Abstract

The Cu-0.8Fe-0.2Mg and Cu-0.8Fe-0.2Mg-0.2Cr alloys were investigated using hot compression experiments at 600–950 °C and 0.003–10 s−1 strain rates. The effects of Cr addition on the microstructure and recrystallized behavior of the Cu-0.8Fe-0.2Mg alloy were characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Experimental results indicated that Cr significantly increased the flow stress of the Cu-0.8Fe-0.2Mg alloy. The established constitutive equations revealed that the activation energy of the Cu-0.8Fe-0.2Mg-0.2Cr alloy was 16.84 % higher than that of the Cu-0.8Fe-0.2Mg alloy. Microstructure analysis demonstrated that the addition of Cr decreased the percentage of high-angle grain boundaries (HAGBs), which inhibited the dynamic recrystallization (DRX) of the Cu-0.8Fe-0.2Mg-0.2Cr alloy. At 800 °C and 0.01 s−1, the texture content of Cu-0.8Fe-0.2Mg alloy was primarily composed of Cube, Brass, and S textures. After chromium was added, the texture became predominantly Brass. TEM results revealed that deformation at 800 °C and 0.01 s−1 led to α-Fe precipitate in the Cu-0.8Fe-0.2Mg alloy, which transformed into the α-(Fe, Cr) with Cr addition. This study provides insights into the high-temperature deformation and microstructure evolution of Cu–Fe–Mg alloys.

Keywords

• Copper alloys
• Hot deformation
• Dynamic recrystallization
• Microstructure evolution