中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 24 No. 9 September 2014 |
(1. School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
2. School of Materials Science and Engineering, University of Shanghai for Science and Technology,
Shanghai 200093, China)
Abstract:In order to investigate nanomechanical properties of nanostructured Ti metallic material, pure Ti films were prepared by magnetron sputtering at the bias voltage of 0-140 V. The microstructure of Ti films was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It is interesting to find that the microstructure of pure Ti films was characterized by the composite structure of amorphous-like matrix embodied with nanocrystallines, and the crystallization was improved with the increase of bias voltage. The hardness of Ti films measured by nanoindentation tests shows a linear relationship with grain sizes in the scale of 6-15 nm. However, the pure Ti films exhibit a soft tendency characterized by a smaller slope of Hall-Petch relationship. In addition, the effect of bias voltage on the growth orientation of Ti films was discussed.
Key words: Ti film; magnetron sputtering; bias voltage; nanocrystalline; Hall-Petch relationship