测试位置对纳米压痕法测Nb/Cu复合材料线材硬度的影响

Cu/Nb composite wires in different diameters were obtained through plastic deformation. Load-displacement curves were tested during nano-indentation test on different regions of the Cu/Nb composite wires. The characteristic of the indents was observed by scanning electron microscopy (SEM) and scanning probe microscopy (SPM). The influence of test region on the hardness of the composite wires was investigated. The results show that the ratio of the final displacement after complete unloading to the displacement at peak load (hf/hmax) was smaller than 0.8, very little pile-up and smooth surface around the indents were found in the nano-composite region of Nb core, Cu-0 and Cu-1 layers. The hardness of this region reflected the hardness of Cu/Nb composite accurately. Moreover, the hardness of the composite increased with the diameter of Cu-Nb wire decreasing.

通过塑性变形获得不同直径的Nb/Cu复合材料线材, 采用纳米硬度计测得其不同区域的载荷-位移曲线, 用SEM和SPM观察压痕的形貌, 研究了测试位置对复合材料硬度测试结果的影响。结果表明: 卸载后的压痕深度与zui大压痕深度的比值(hf/hmax)不大于0.8时, 位于铌丝、Cu-0层和Cu-1层纳米复合区域的压痕周围只存在极少量堆积, 压痕表面比较平整, 其硬度可以准确地反映Nb/Cu复合材料的硬度; 另外, 随着复合材料直径的减小, 材料硬度呈现明显的上升趋势。