In order to improve the mechanical properties of twinning-induced plasticity steel, the grain morphology was tailored by different solidification technologies combined with deformation and heat treatment processing ro...In order to improve the mechanical properties of twinning-induced plasticity steel, the grain morphology was tailored by different solidification technologies combined with deformation and heat treatment processing routes. Three typical grain morphologies, i.e., equiaxed, columnar as well as equiaxed/columnar grains were formed, and their mechan- ical behaviors were comparatively studied. Among the three materials, the equiaxed grain material exhibited the highest strength but the lowest plasticity. Depending on the grain size, the smaller the grain size, the higher the strength, but the lower the elongation. The columnar grain material pos- sessed the most excellent plasticity but the weakest strength. These properties presented a non-monotonic dependence on the dendrite spacing, and the moderate spacing resulted in the optimum combination of strength and plasticity. The equiaxed/columnar grain coexisted material showed inter- esting properties, i.e., the strength and plasticity were just between those of single grain-shaped materials. The three materials also presented different strain hardening behaviors particularly in the uniform deformation stage. The equiaxed grain material showed a constant strain hardening rate, while the columnar grain and equiaxed/columnar grain materials showed a progressively increasing rate with increasing the true strain.展开更多
Zn enriched coatings with distinct microstructures and properties were fabricated on Mg foams by a modified thermal evaporation technique using a tubular resistance furnace. As the temperature and kinetic energy of Zn...Zn enriched coatings with distinct microstructures and properties were fabricated on Mg foams by a modified thermal evaporation technique using a tubular resistance furnace. As the temperature and kinetic energy of Zn vapor varied along the tubular system, a spatial variation of preparation conditions was created and the obtained coatings were found to follow two growth mechanisms: a thermal diffusion pattern in high-temperature zone and the a relatively low-temperature deposition model. AZn-based deposition coating with dense texture and nearly uniform structure was acquired while Mg foam was placed 20 cm far from the evaporation source, where the Zn vapor deposition model dominated the coating growth.Mechanical properties and bio-corrosion behaviors of the samples were investigated. Results showed that the Zn coatings brought dramatic improvements in compression strength, but exhibited differently in biodegradation performance. It was confirmed that the diffusion layer accelerated corrosion of Mg foam due to the galvanic effect, while the Zn-based deposition coating displayed excellent anti-corrosion performance, showing great potential as bone implant materials. This technique provides a novel and convenient approach to tailor the biodegradability of Mg foams for biomedical applications.展开更多
Three-dimensional(3D) ZnO nanorods with good adsorption property was successfully fabricated via a facile hydrothermal method, and characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Ener...Three-dimensional(3D) ZnO nanorods with good adsorption property was successfully fabricated via a facile hydrothermal method, and characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Energy Dispersive X-ray spectrometer(EDX) and a UV-vis spectrophotometer. It was found that the ZnO nanorods with a diameter of 0.5 μm and the length of 10 μm were firmly grown on the struts of the open-cell aluminum foams, and the 3D hierarchical structured adsorbent Zn O nanorods/Al foam(r-ZnO/AF) exhibits a higher adsorption capacity for Brilliant Blue R(BBR) in aqueous solutions, more stable sorption regenerable behavior and solid–liquid separability in contrast to the corresponding n-ZnO powder sample. The kinetics of the adsorption process was also discussed.展开更多
Designing and developing the highly efficient photocatalysts is full of significance to achieve spontaneous photolysis water.In this work,using the first-principles calculations,we have performed a systematic theoreti...Designing and developing the highly efficient photocatalysts is full of significance to achieve spontaneous photolysis water.In this work,using the first-principles calculations,we have performed a systematic theoretical study of water splitting photocatalytic activity of the InS e/g-CN heterojunction.It is concluded that the In Se/g-CN heterojunction is a typical type-II semiconductor,whose electrons and holes can be effectively separated.And the potential of the conduction band minimum(CBM)and valence band maximum(VBM)satisfy the requirements for photolysis water.Moreover,the changes of Gibbs free energy(ΔG)of the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER)are calculated to investigate thermodynamic sustainability of photolysis water.The results show that when pH=7,the potential driving force provided by the InSe/g-CN heterojunction can ensure the spontaneous progress of HER and OER.In addition,it is found that the solar conversion efficiency(η;)of the In Se/g-CN heterojunction is up to 13.7%,which indicates it has broad commercial application prospects.Hence,the In Se/g-CN heterojunction is expected to be an excellent candidate for photolysis water.展开更多
基金the key direction project of Chinese Academy of Sciences on the high speed rail and the National Natural Science Foundation of China (Grant 51371167)
文摘In order to improve the mechanical properties of twinning-induced plasticity steel, the grain morphology was tailored by different solidification technologies combined with deformation and heat treatment processing routes. Three typical grain morphologies, i.e., equiaxed, columnar as well as equiaxed/columnar grains were formed, and their mechan- ical behaviors were comparatively studied. Among the three materials, the equiaxed grain material exhibited the highest strength but the lowest plasticity. Depending on the grain size, the smaller the grain size, the higher the strength, but the lower the elongation. The columnar grain material pos- sessed the most excellent plasticity but the weakest strength. These properties presented a non-monotonic dependence on the dendrite spacing, and the moderate spacing resulted in the optimum combination of strength and plasticity. The equiaxed/columnar grain coexisted material showed inter- esting properties, i.e., the strength and plasticity were just between those of single grain-shaped materials. The three materials also presented different strain hardening behaviors particularly in the uniform deformation stage. The equiaxed grain material showed a constant strain hardening rate, while the columnar grain and equiaxed/columnar grain materials showed a progressively increasing rate with increasing the true strain.
基金supported by the National High-Tech R&D Program of China ("863 Program", No. 2015AA034405)the National Natural Science Foundation of China (No. 51301168)
文摘Zn enriched coatings with distinct microstructures and properties were fabricated on Mg foams by a modified thermal evaporation technique using a tubular resistance furnace. As the temperature and kinetic energy of Zn vapor varied along the tubular system, a spatial variation of preparation conditions was created and the obtained coatings were found to follow two growth mechanisms: a thermal diffusion pattern in high-temperature zone and the a relatively low-temperature deposition model. AZn-based deposition coating with dense texture and nearly uniform structure was acquired while Mg foam was placed 20 cm far from the evaporation source, where the Zn vapor deposition model dominated the coating growth.Mechanical properties and bio-corrosion behaviors of the samples were investigated. Results showed that the Zn coatings brought dramatic improvements in compression strength, but exhibited differently in biodegradation performance. It was confirmed that the diffusion layer accelerated corrosion of Mg foam due to the galvanic effect, while the Zn-based deposition coating displayed excellent anti-corrosion performance, showing great potential as bone implant materials. This technique provides a novel and convenient approach to tailor the biodegradability of Mg foams for biomedical applications.
基金supported by the National Natural Science Foundation of China(Nos.51371167 and 51301168)the Natural Science Foundation of Anhui Province(No.1508085ME99)Key Science and Technology Program of Anhui Province of China(No.1604a0902173)
文摘Three-dimensional(3D) ZnO nanorods with good adsorption property was successfully fabricated via a facile hydrothermal method, and characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Energy Dispersive X-ray spectrometer(EDX) and a UV-vis spectrophotometer. It was found that the ZnO nanorods with a diameter of 0.5 μm and the length of 10 μm were firmly grown on the struts of the open-cell aluminum foams, and the 3D hierarchical structured adsorbent Zn O nanorods/Al foam(r-ZnO/AF) exhibits a higher adsorption capacity for Brilliant Blue R(BBR) in aqueous solutions, more stable sorption regenerable behavior and solid–liquid separability in contrast to the corresponding n-ZnO powder sample. The kinetics of the adsorption process was also discussed.
基金supports by National Natural Science Foundation of China(NSFC,Nos.51471124,U1766216)National Key R&D Program of China(No.2018YFB0905600)+1 种基金Natural Science Foundation of Shaanxi province,China(Nos.2019JM-189,2020JM218)supported by HPC Platform,Xi’an Jiaotong University。
文摘Designing and developing the highly efficient photocatalysts is full of significance to achieve spontaneous photolysis water.In this work,using the first-principles calculations,we have performed a systematic theoretical study of water splitting photocatalytic activity of the InS e/g-CN heterojunction.It is concluded that the In Se/g-CN heterojunction is a typical type-II semiconductor,whose electrons and holes can be effectively separated.And the potential of the conduction band minimum(CBM)and valence band maximum(VBM)satisfy the requirements for photolysis water.Moreover,the changes of Gibbs free energy(ΔG)of the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER)are calculated to investigate thermodynamic sustainability of photolysis water.The results show that when pH=7,the potential driving force provided by the InSe/g-CN heterojunction can ensure the spontaneous progress of HER and OER.In addition,it is found that the solar conversion efficiency(η;)of the In Se/g-CN heterojunction is up to 13.7%,which indicates it has broad commercial application prospects.Hence,the In Se/g-CN heterojunction is expected to be an excellent candidate for photolysis water.