Abstract—

The evolution of structure of a multicore in situ Cu-18Nb composite under high-pressure torsion (HPT) by one, three, and five anvil revolutions was investigated by scanning and transmission electron microscopy, and microhardness measurements. Thermal stability of the HPT deformed structure was studied after annealings in the 300–800°C temperature range. The combined use of repeated cold drawing and HPT made it possible to refine the structure and thereby to obtain equiaxed grains with a size of 10–30 nm, which sharply increased the microhardness (to 4800 MPa). Under the subsequent annealing the nanocrystalline structure is retained and; the microhardness remains considerably higher than that of the composite not subjected to HPT. Thus, the combination of repeated cold drawing with further high-pressure torsion provided substantial strengthening and higher thermal stability of the composite in comparison with niobium and copper nanostructured by severe plastic deformation.

中文翻译：

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高压扭转及后续退火作用下Cu-Nb复合材料的结构演变

摘要-

通过扫描，透射电子显微镜和显微硬度测量，研究了多芯原位Cu-18Nb复合材料在高压，三砧和五砧旋转下的演变。在300–800°C温度范围内进行退火后，对HPT变形结构的热稳定性进行了研究。反复冷拔和HPT的结合使用，使结构细化成为可能，从而获得尺寸为10–30 nm的等轴晶粒，这极大地提高了显微硬度（至4800 MPa）。在随后的退火下，保留了纳米晶体结构，并且；显微硬度仍远高于未进行HPT的复合材料。因此，