Selective strategy of reactive hysteresis loop for coatings on alloy substrates with different moduli
Selective strategy of reactive hysteresis loop for coatings on alloy substrates with different moduli
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DOI：
10.1116/6.0003127
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发表时间：
2023-12
期刊：
影响因子：
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通讯作者：
Biao Si;Linfan Sun;Zhiwei Su;Kaice Zhang;Jing Guo;Minqi Hua;Yanwen Zhou
中科院分区：
文献类型：
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作者：
Biao Si;Linfan Sun;Zhiwei Su;Kaice Zhang;Jing Guo;Minqi Hua;Yanwen Zhou
氮化膜（例如氮化钛（TiN））的结构和性质取决于反应气体（N2）流速，其通常根据反应磁滞回线来选择。薄膜-基材的粘附力取决于薄膜和基材的性质。通过对Ti6 Al 4V钛合金（TC 4）和4Cr 5 MoSiV 1热作模具钢（H13）表面TiN薄膜的结构、性能和失效机理的分析，研究了滞后回线内反应气体流量的选择策略。测量了钛（Ti）靶电位的滞后回线随N2流量的变化，并采用不同溅射模式下的流量，利用等离子体增强磁控溅射法制备TiN薄膜。随着N2流量从5 cm 3/min、10 cm 3/min、15 cm 3/min增加到20 cm 3/min，薄膜形貌由疏松变为致密，相结构由TiN0.3（002）变为TiN（111）、（200）和（220），纳米硬度和弹性模量增加。施加洛氏法向载荷时，TiN/TC 4出现不对称的圆形裂纹，并且当N2流量增加到15-20 cm 3/min时，该裂纹变得显著;仅在20 cm 3/min的N2流速下在TiN/H13中观察到裂纹。施加法向和剪切划痕应力，TiN膜从TC 4上剥离，除了TiN，N2流速为10 cm 3/min，表明TiN和TC 4之间的粘附力弱。在TiN/H13的划痕形貌中没有观察到剥离碎片，表明TiN/H13膜与H13基底之间具有优异的附着力。在TiN0.3的划痕形貌中出现了圆形裂纹，表明膜内的结合力已被破坏。TiN和TC 4薄膜的弹性模量和硬度差异很大，导致TC 4薄膜的弹性和塑性变形比TiN薄膜早得多。数值模拟结果表明，TiN/TC 4在正常载荷下的界面拉应力较高，压痕边缘附近的界面应变大于TiN/H13。综合性能考虑，对于低硬度低模量基体上的氮化膜，应采用临界点附近的反应流速，如TiN/TC 4为15 cm 3/min;对于高硬度高模量基体上的氮化膜，在复合模式阶段，TiN/H13为20 cm 3/min。
The structure and properties of nitride films, such as titanium nitride (TiN), depend on the reactive gas (N2) flow rates, which are normally selected according to the reactive hysteresis loops. Film-substrate adhesion depends on the properties of the films and substrates. A selective strategy for the reactive gas flow rate within the hysteresis loop was investigated by characterizing the structure, properties, and failure mechanisms of TiN films on Ti6Al4 V titanium alloy (TC4) and 4Cr5MoSiV1 hot-work die steel (H13). The hysteresis loop of the titanium (Ti) target potential as a function of the N2 flow rate was measured, and flow rates in different sputtering modes were used to prepare TiN films using plasma-enhanced magnetron sputtering. As the N2 flow rate increased from 5 cm3/min, 10 cm3/min, 15 cm3/min to 20 cm3/min, from the metallic mode to the compound mode, the morphologies of the films changed from loose to dense, the phase structures changed from TiN0.3 (002) to TiN (111), (200), and (220), and the nano-hardness and elastic moduli increased. Applying a Rockwell normal load, asymmetric circular cracks appeared and became significant for TiN/TC4 as the N2 flow rate increased to 15–20 cm3/min; cracks were only observed in TiN/H13 at an N2 flow rate of 20 cm3/min. Applying normal and shear scratch stresses, the TiN films peeled off from the TC4, except for TiN, with an N2 flow rate of 10 cm3/min, indicating that the adhesion between TiN and TC4 was weak. No peel-off chips were observed in the scratch morphologies of TiN/H13, indicating excellent adhesion between the films and H13 substrate. Circular cracks appeared in the scratch morphology of TiN0.3, indicating that cohesion had broken within the film. The possible failure mechanism was the large difference in the elastic moduli and hardness of TiN and TC4, which led to TC4 elastic and plastic deformation much earlier than in TiN films. According to numerical simulation, the interfacial tensile stress of TiN/TC4 under a normal load was higher, and the interfacial strain near the indentation edges was larger than that of TiN/H13. Considering the comprehensive properties, a reactive flow rate near the critical point such as 15 cm3/min for TiN/TC4 should be used for the nitride film on a low-hardness and low-modulus substrate; in the compound mode stage, 20 cm3/min for TiN/H13 should be used for the nitride film on a high-hardness and high-modulus substrate.