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通过SMAT技术实现了工业纯钛表面纳米化,并利用X射线衍射(XRD)、扫描电镜和高分辨率透射电子显微镜(HRTEM)分析技术对表面纳米结构层进行了表征,对比研究了工业纯钛和经SMAT处理表面纳米化工业纯钛的拉伸性能,讨论了表面纳米化对工业纯钛拉伸性能的影响。结果表明:经SMAT处理后,由于表面纳米晶的形成和变形层中高密度的孪晶与位错共同的作用,工业纯钛的屈服强度、抗拉强度提高而伸长率降低。试样经SMAT处理后,沿处理面到中心晶粒尺寸不同,使得SMAT试样拉伸断裂后处理面与中心的断裂类型不同,表面纳米晶层和亚晶层的断裂主要是滑移分离断裂,而基体粗晶部分断裂为微孔聚集型断裂。
The surface of nanostructured titanium was nano-sized by SMAT technology. The surface nanostructured layers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) And the tensile properties of nanosized pure titanium treated by SMAT were discussed. The effects of surface nanocrystallization on the tensile properties of industrial pure titanium were discussed. The results show that after SMAT treatment, the yield strength, tensile strength and elongation of industrial pure titanium decrease due to the formation of surface nanocrystal and the high density of twins and dislocations in the deformed layer. After SMAT treatment, the size of grain along the treated surface to the center is different, so that the fracture type of the treated surface and the center of the SMAT specimen after tensile fracture is different. The fracture of the surface nanocrystalline layer and the sub-crystalline layer is mainly the slip separation fracture , While the coarse part of the matrix fracture is micro-pore aggregation type fracture.