脉冲偏压对电弧离子镀Ti/TiN纳米多层薄膜显微硬度的影响

采用脉冲偏压电弧离子镀方法在高速钢基体上沉积Ti／TiN纳米多层薄膜，采用正交实验法设计脉冲偏压电参数，考察脉冲偏压对Ti／TiN纳米多层薄膜显微硬度的影响．结果表明，在所有偏压参数（脉冲偏压幅值、占空比和频率）和几何参数（调制周期和周期比）中，脉冲偏压幅值是影响显微硬度的最主要因素；当沉积工艺中脉冲偏压幅值为900V、占空比为50％及频率为30kHZ时，薄膜硬度可高达34．1GPa，此时多层膜调制周期为84nm，TiN和Ti单元层厚度分别为71和13nm；由于薄膜中的单层厚度较厚，纳米尺寸的强化效应并未充分体现于薄膜硬度的贡献中，硬度的提高主要与脉冲偏压工艺，尤其是脉冲偏压幅值对薄膜组织的改善有关．

EFFECT OF PULSED BIAS ON MICROHARDNESS OF Ti/TiN MULTILAYER FILMS DEPOSITED BY ARC ION PLATING

Ti/TiN nano-multilayer films were deposited on high-speed-steel (HSS) substrates using arc ion plating, and orthogonal experiments were used to analyze the effects of the electrical parameters of pulsed bias on microhardness of Ti/TiN multilayer films. The results show that in all the pulsed bias related parameters (pulsed bias magnitude, duty ratio and frequency) and the geometry parameters (modulation period and period ratio), pulsed bias magnitude is the major factor affecting microhardness of the multilayer films. The maximum microhardness of 34.1 GPa was obtained with pulsed bias magnitude 900 V, duty ratio 50% and frequency 30 kHz, and the responding modulation period is 84 nm, the single layer thicknesses of TiN and Ti are 71 and 13 nm, respectively. Due to the large single layer thickness, the nano-scale strengthening effect is not obviously manifested. The increase of the microhardness correlates mainly with refinement of microstructure resulted from the pulsed bias parameters especially the pulsed bias magnitude.