Enhanced room-temperature tensile ductility of columnar-grained polycrystalline Cu-12 wt.%Al alloy through texture control by Ohno continuous casting process

摘要

The Ohno continuous casting (OCC) process is a practical way to control the solidification texture of Cu-12 wt. %AI alloy with a perfect <001>ss fiber texture along the solidification direction. Compared with the conventional randomly oriented polycrystalline Cu-12 wt.%Al alloy, the reorientation of ss_1 martensite and stress-induced phase transformation occurred at the same time within every columnar grain sharing the same [001]ss orientation during tensile test, which would reduce the elastical and phase-transformational incompatibility and enhance the intergranular accommodation. As a consequence, a high tensile ductility up to 28% with transgranular fracture can be obtained for OCC columnar-grained Cu-12 wt.%AI alloy instead of intergranular fracture due to the incompatible stress at the grain boundary for randomly oriented polycrystalline Cu-12 wt.%Al alloy.