工业纯锆ECAP单道次变形组织与性能研究

Effect of One Pass ECAP on Microstructure and Properties of Commercial Purity Zirconium

室温下采用常规等径弯曲通道变形(ECAP)模具(通道夹角90°,内圆角20°)成功实现工业纯锆ECAP单道次变形。通过金相显微镜、透射电子显微镜(TEM)、X射线衍射(XRD)及单向拉伸实验等测试方法,研究ECAP变形后工业纯锆的组织与性能。研究结果表明:工业纯锆经过通道夹角为90°模具单道次ECAP变形后,晶粒显著破碎,屈服强度和抗拉强度分别提高到397和536 MPa,增幅分别为~43%和~53%;其硬度值也由原始样的1050 MPa提高到了约1550 MPa;材料仍保持有较好的延伸率,延伸率为21.2%。TEM结果显示工业纯锆单道次ECAP变形后试样有大量的板条、位错及位错胞存在。XRD结果表明经ECAP变形后,工业纯锆原始的基面织构和锥面织构转变成了柱面织构。

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°. The CP-Zr during one pass ECAP at room temperature was characterized by OM, TEM, SEM, XRD and tensile tests. The results show that the grain of CP-Zr processed by one pass ECAP is refined distinctly. The yield strength and ultimate tensile strength increase to 397 and 536 MPa（rate increase up to -43% and -53%）, respectively. The microhardness value increases from 1050 MPa to 1550 MPa. The CP-Zr maintains good elongation, which is 21.2%. The TEM observation of the processed CP-Zr proves the existence of elongated bands, dislocations and dislocation cells. The results of XRD indicate that the basal texture and pyramidal texture are transformed to prismatic texture.