【摘要】 利用表面机械研磨处理(SMAT)技术在Zr片状拉伸样品表面施加剧烈变形,获得超细纳米晶粒组织的变形细化表层,其中Zr板厚度1mm ,两侧变形层厚度均为1 0 0 μm。拉伸实验结果表明,表层细化组织提高了屈服强度和抗拉强度,使加工硬化能力及伸长率下降。应变速率在1 0 - 4～1 0 - 3s- 1 范围时,拉伸强度随应变速率的提高而提高;应变速率增大至1 0 - 2 s- 1 量级时,抗拉强度下降。扫描电镜观察显示出韧性韧窝状断裂特征。更多还原

【Abstract】 By means of the surface mechanical attrition treatment (SAMT) technique, an ultrafine grain and nanocrystalline surface layer was prepared on two sides of tensile samples of zirconium. The mechanical properties were determined by tensile tests. It is observed that surface nanocrystallization leads to an increase in yield strength and ultimate tensile strength and to decrease in uniform elongation, compared with as-received ones. The tensile strength increases with increasing strain rates in the range of 10 -4～10 -3 s -1 whereas decreases when strain rate is higher than 10 -2 s -1.SEM observation reveals the dimple characteristics on the tensile fracture surface.更多还原