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.

Key words:Commercial;purity zirconium, ECAP, Microstrucure;and properties, Texture