STUDIES ON TEXTURE AND MICROSTRUCTURE OF CRYOROLLED AND ANNEALED Cu-5Al, Cu-5Zn ALLOYS

摘要

In the present work, we report the crystallographic texture, microstructure and elastic modulus in Cu-5 wt. % Al and Cu-5 wt. % Zn alloys after cryorolling (true strain of e ~ 2) and annealing. Texture was studied using X-ray diffraction and electron back scatter diffraction in the scanning electron microscope. Cu-Al and Cu-Zn alloys were found to develop a strong texture after cryorolling and the texture weakens considerably following annealing in the range of 250-300°C. In-situ Young's modulus (E) measurements (using resonance technique) at temperatures from 25-300°C revealed that E is lowest in both the alloys (108-112 GPa) in the as-rolled condition and recovers to the isotropic value (128 GPa) after heating to 250-300°C. This could be correlated to the rolling and annealing textures in both the alloys. After annealing at 250°C for 15 min, a recrystallized ultra fine grained microstructure with an average grain size in the range of 0.5-1 μm with very fine twins was obtained in both the alloys. The grain boundary character distribution revealed significant fraction of CSL boundaries in both the alloys.