N_2分压对ZrN/WN纳米多层膜缺陷性质与力学性能的影响

Effect of N_2 partial pressure on the defect properties and mechanical behaviors of nanoscale ZrN/WN multilayers

利用射频磁控溅射系统在不同N2分压的条件下,制备了一系列ZrN/WN纳米多层膜.借助慢正电子湮没技术分析了样品的缺陷性质,采用纳米压痕仪研究了多层膜的力学性能.结果发现:N2分压为0.4Pa的多层膜具有最小的空位型缺陷浓度,其中心层和膜基结合层的平均S参数分别为0.4402和0.4641,而较低或较高的N2分压都可能导致空位型缺陷浓度的增加.随着空位型缺陷浓度的减小,多层膜的硬度和临界载荷增大.对于空位型缺陷浓度最小的多层膜,其硬度和临界载荷达到最大值,分别为34.8GPa和100mN,说明较低的缺陷浓度有利于提高多层膜的力学性能.

ZrN/WN nanoscale multilayer coatings were synthesized with different N2 partial pressure by radio frequency magnetron sputtering. The vacancy-defect properties were measured by slow positron annihilation, and mechanical behaviors were studied using nanoindentation. The results indicate that the multilayer coating with N2 partial pressure of 0.4 Pa has the lowest concentration of vacancy-defects, and the average S-parameters of the central and the combination layers are 0.4402 and 0.4641, respectively. Lower or higher N2 partial pressure results in an increase in vacancy-defect concentration. With vacancydefect concentration decreasing, the hardness and critical load of muhilayer coatings increase. The multilayer coating with lowest concentration of vacancy-defects also exhibits maximum hardness and critical load （34.8 GPa and 100 mN）. The decrease of vacancy-defect concentration is helpful to improve the mechanical properties of multilayer coatings.