Effect of one pass ECAP on Microstructure and Properties of Commercial Purity Zirconium

Abstract:

Commercial purity zirconium (CP-Zr) was processed by Equal channel angular pressing(ECAP) at room temperature using a die with an internal angle Φ of 90°and an outer curvature angle Ψ of 20°. Advanced characterization and measurement techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and so on, were used to analyse microstructural evolution of CP-Zr during one pass ECAP at room temperature. The results showed that the grain of CP-Zr processed by one pass ECAP was refined distinctly. The yield strength and ultimate tensile strength were increased to 397 MPa and 536 MPa (rate of increase up to ~43% and ~53%), respectively. The microhardness value was increased to 1550 MPa. The elongation to failure maintained well. The microstructures of processed CP-Zr observed by TEM proved the existence of elongated bands, dislocations and dislocation cells. The results of XRD indicated that the basal texture and pyramidal texture were transformed to prismatic texture.