脉冲持续时间对Ti纳米晶薄膜结构及性能的影响

Effect of pulse duration on the structure and properties of Ti nano-crystalline films

摘要:

采用大功率脉冲离子镀技术,通过调控单脉冲持续时间的方式,对所制备的纯金属细晶粒Ti薄膜的微观结构以及相关力学性能进行了对比研究。结果表明：在较小平均电流条件下,通过调控脉单冲持续时间T_on(占空比)可以获得较大峰值电流,并对薄膜的微观结构产生显著影响。薄膜的表面生长形貌表现为随着单脉冲持续时间的延长,颗粒间逐渐出现明显的孔隙,圆球状团聚生长的尺寸明显增大。截面生长形貌表现为随着脉冲持续时间的延长,发生由柱状形貌向树枝状形貌过渡,并产生大量的孔隙与缺陷,薄膜致密度明显下降。力学性能表现为随着脉冲持续时间的延长,薄膜的硬度与模量都呈现出先增大后大幅降低的变化趋势,且当单脉冲持续时间为4ms左右时,薄膜的硬度与模量存在最大值。

Abstract:

The microstructure and mechanical properties of nano-crystalline Ti films were studied with different pulse duration,which were deposited by the High Power Pulsed ion plating. The results shows that when the average current kept in low value, the larger peak current can be obtained by adjusting the pulse duration (duty ratio), which has a significant effect on the microstructure of the thin film. The surface morphologies showed gradually appeared apparent porosity of the particles and the growth dimensions of the spherical agglomeration significantly increases with the single pulses duration prolonged. The cross section of the growth showed that the morphology transition from the columnar to the dendritic with the extension of the duration of the pulse, while a large number of pores and defects occurred and the density of the films decreased obviously. The hardness and modulus of the films are showing increased first and the substantially reduced trend with the prolonged of the pulse duration. The value of the hardness and modulus exist the maximum when the single pulse duration reached about 4ms.