| 摘要: |
| AlCrN 薄膜因其具有优异的力学性能广泛应用于金属切削领域，Mo 和 C 的掺杂对提高 AlCrN 薄膜的硬度和耐磨性有理论上的可行性，然而 Mo 和 C 元素的共同作用对 AlCrN 薄膜的组织结构、力学性能及摩擦学性能的影响仍须进一步探索。使用中频反应磁控溅射和热丝弧离子镀复合薄膜设备在硬质合金和 Si(100)表面制备 AlCr(MoC)N 薄膜。使用 SEM、XRD 和 EDS 分析薄膜的微观形貌、物相组成和元素含量，采用纳米压痕测试仪、摩擦磨损试验仪和 3D 轮廓仪表征薄膜的硬度、耐磨损性并观察薄膜的磨痕形貌。结果表明：随着 MoC 镶嵌靶(Mo 和 C 等面积)电流的增加，Mo 和 C 元素含量上升，当 MoC 靶电流为 2.5 A 时，薄膜中 Mo 和 C 的含量分别升至约 14.6 at.%和 9.1 at.%。与 AlCrN 薄膜相比，AlCrMoCN 薄膜中出现 β-Mo2N 和 γ-Mo2N 相，c-CrN 相的生长从高表面能(111)面转变为低表面能(200)面。随着 Mo 和 C 元素含量的增加，薄膜硬度先增加后减小，靶电流为 1 A 时薄膜硬度达到最大值 35±0.5 GPa，在 MoC 靶电流为 2.5 A 时，薄膜出现可由 SEM 观察到的纳米多层结构，此时 AlCrMoCN 薄膜硬度下降至约 23±1 GPa。随着 Mo 和 C 元素含量的增加，薄膜的残余压应力由 4.8±1 GPa 减小至 2.2±0.1 GPa。与无 Mo 和 C 薄膜相比，Mo 和 C 的掺杂有利于降低 AlCrN 薄膜的摩擦因数，Mo 和 C 含量增高，薄膜的摩擦因数大小呈现相近的趋势。AlCrMoCN 薄膜在与 Si3N4对偶球对磨时获得相较于 Al2O3对偶球更低的磨损率。对比分析 AlCrN 薄膜在不同 Mo 和 C 含量下的力学性能及摩擦学性能，揭示 Mo 和 C 的作用机理，可对其实际应用场景提供指导。 |
| 关键词: AlCr(MoC)N 薄膜 微观结构 硬度 残余应力 摩擦磨损性能 |
| DOI：10.11933/j.issn.1007?9289.20220411004 |
| 分类号:TG178;TH117 |
| 基金项目:国家自然科学基金(52165021，51805102)和贵州省科学技术基金(黔科合基础[2020]1Y228)资助项目 |
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| Effect of Mo and C Contents on the Crystal Structure and Properties of AlCrN Films |
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SHI Jie1, CHEN Yun2, LIU Hao1, KANG Jianjun1, LI Xiaoyang1, ZHANG Li1, XIAN Guang3, DU Hao1,4
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1.School of Mechanical Engineering, Guizhou University, Guiyang 550025 , China;2.Chengdu Tool Research Institute Co., Ltd., Chengdu 610500 , China;3.School of Mechanical Engineering, Sichuan University, Chengdu 610065 , China;4.Key Laboratory of Advanced Manufacturing Tchnology of Ministry of Education, Guizhou University, Guiyang 550025 , China
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| Abstract: |
| AlCrN is widely used as cutting tool coating because of its excellent mechanical properties. The doping of Mo and C is theoretically feasible to improve the hardness and wear resistance of AlCrN film, however, the effect of the combined effect of Mo and C elements on the structure, mechanical properties and tribological properties of AlCrN thin film still needs to be further explored. AlCr(MoC)N films are grown on cemented carbides and Si(100) surfaces by using a hybrid PVD apparatus (medium frequency magnetron sputtering and ion plating evaporation). SEM and XRD and EDS are applied to analyze the crystal structure, phase, and elemental composition of the films. The hardness, tribological behavior, and wear track morphology are evaluated by nanoindentation tester, tribotester, and 3D profilometer, respectively. The results indicate that as the current of the MoC mosaic target (with equal area for Mo and C) increases, Mo and C content increases. As MoC target current reaches 2.5 A, Mo and C contents increase to around 14.6 at.% and 9.1 at.%, respectively. AlCrMoCN films are composed of β-Mo2N and γ-Mo2N phases, and the growth of the c-CrN phase changes from a high surface energy (111) plane to low surface energy (200) plane with the increasing content of Mo and C. With the increase of Mo and C content, the film hardness increases and then decreases, and the highest hardness of 35±0.5 GPa is achieved by the film grown at the MoC target current of 1 A. As the MoC target current reaches 2.5 A, a multilayer structure is observed in SEM images, during which the hardness of AlCrMoCN film decreases to around 23±1 GPa. In addition, the compressive stress of the films decreases from 4.8±1 GPa to 2.2±0.1 GPa with the MoC target current increasing from 0 A to 2.5 A. The doping of Mo and C favors the reduction of the friction coefficient of AlCrN films compared to Mo and C free films, with increasing Mo and C content showing a similar trend in the magnitude of the friction coefficient of the films. Lower wear rates for AlCrMoCN films are obtained when the Si3N4 counterpart is used as compared to Al2O3. A comparative analysis of the mechanical and tribological properties of AlCrN films at different Mo and C contents reveals the mechanism of Mo and C effects and provides guides to practical application scenarios. |
| Key words: AlCr(MoC)N films microstructure hardness residual stress friction and wear properties |
