分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Li, XW [Li, Xiaowei][ 1 ]
Guo, P [Guo, Peng][ 1 ]
Sun, LL [Sun, Lili][ 1 ]
Wang, AY [Wang, Aiying][ 1 ]
Ke, PL [Ke, Peiling][ 1 ]
摘要： Amorphous carbon films (a-C) codoped by two metal elements exhibit the desirable combination of tribological and mechanical properties for widely potential applications, but are also prone to catastrophic failure due to the inevitable residual compressive stress. Thus far, the residual stress reduction mechanism remains unclear due to the insufficient understanding of the structure from the atomic and electronic scale. In this paper, using ab initio calculations, we first designed a novel Cu/Cr codoped a-C film and demonstrated that compared with pure and Cu/Cr monodoped cases, the residual stress in Cu/Cr codoped a-C films could be reduced by 93.6% remarkably. Atomic bond structure analysis revealed that the addition of Cu and Cr impurities in amorphous carbon structure resulted in the critical and significant relaxation of distorted C−C bond lengths. On the other hand, electronic structure calculation indicated a weak bonding interaction between the Cr and C atoms, while the antibonding interaction was observed for the Cu−C bonds, which would play a pivot site for the release of strain energy. Those interactions combined with the structural evolution could account for the drastic residual stress reduction caused by Cu/Cr codoping. Our results provide the theoretical guidance and desirable strategy to design and fabricate a new nanocomposite a-C films with combined properties for renewed applications.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Li, XW [Li, Xiaowei][ 1 ]
Xu, SP [Xu, Shipeng][ 1,2 ]
Ke, PL [Ke, Peiling][ 1 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： Molecular dynamics simulation was performed to investigate the effect of thickness on the properties and struc- ture of ultrathin tetrahedral amorphous carbon films (ta-C). The present simulation showed that both the density and residual compressive stress decreased with increasing the thickness of ultrathin ta-C films, which was in agreement with the experimental results. The gradient of properties with the thickness was dependent on the incident kinetic energy of deposited atoms; when the incident kinetic energy was 10 eV/atom, the slower gradient was observed. Further structural analysis indicated that the critical relaxation of highly distorted bond angles was responsible for the reduction of residual compressive stress in the films deposited at 10 eV/atom, while the joint relaxation of both the distorted bond angles and C\C bond length led to the fast release of residual compressive stress in the films deposited at 70 eV/atom.
提交时间： 2017-05-02
Wang, ZY [Wang, Zhenyu][ 1,2 ]
Zhang, D [Zhang, Dong][ 1 ]
Ke, PL [Ke, Peiling][ 1 ]
Liu, XC [Liu, Xincai][ 2 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： TiN coatings were deposited using a hybrid home-made high power impulse magnetron sputtering [HIPIMS] technique at room temperature. The effects of substrate negative bias voltage on the deposition rate, composition, crystal structure, surface morphology,
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Feng, ZJ [Feng, Zongjian][ 1 ]
Ke, PL [Ke, Peiling][ 1 ]
Huang, Q [Huang, Qing][ 2 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： The scale behavior of Ti2AlC coating at 750 °C in air and pure water vapor was investigated. A four-layered scale, a thick TiO2 and Al2O3 mix oxide outer layer, followed by a thin α-(Al, Cr)2O3 sublayer, a thick Fe2O3 and TiO2 mix oxide mid-layer and a thin Al2O3-rich oxide inner layer in sequence, developed on the Ti2AlC coatings in air. Whereas internal oxidation occurred, no distinct oxide scale formed on the Ti2AlC coating in the case of the oxidation in pure water vapor. The Ti2AlC coating improved the oxidation resistance of 316LSS in air, especially in wet air.
提交时间： 2017-05-02
Guo, P [Guo, Peng][ 1 ]
Sun, LL [Sun, Lili][ 1 ]
Li, XW [Li, Xiaowei][ 1 ]
Xu, S [Xu, Sheng][ 2 ]
Ke, PL [Ke, Peiling][ 1 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： Cu-containing diamond-like carbon [Cu-DLC] films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration [0.1-39.7 at.%] in the film was controlled by varying the sputtering current. The microstructure and composi
提交时间： 2017-05-02
Wang, ZY [Wang, Zhenyu][ 1 ]
Li, XW [Li, Xiaowei][ 1 ]
Zhou, J [Zhou, Jie][ 2 ]
Liu, P [Liu, Pei][ 1 ]
Huang, Q [Huang, Qing][ 2 ]
Ke, PL [Ke, Peiling][ 1 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： V2AlC belongs to a family of ternary nano-laminate alloys known as the MAX phases, which exhibit a unique combination of metallic and ceramic properties. In this work V-Al-C coatings with deposited [V, Al][2]C nano-crystallines and amorphous phase were ma
提交时间： 2017-05-02
Li, XW [Li, Xiaowei][ 1 ]
Sun, LL [Sun, Lili][ 1 ]
Guo, P [Guo, Peng][ 1 ]
Ke, PL [Ke, Peiling][ 1 ]
Wang, AY [Wang, Aiying][ 1 ]
摘要： Here, we selected Ti, Cr, and Was the representative metal elements to composite with Al atom in order to generate co-doped amorphous carbon [a-C] films using ab initio calculations. Results show that compared with the pure and mono-doped cases, the Ti/Al
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