Thermodynamically stable and ultra-thin “phase” at the interface, known as complexions, can significantly improve the mechanical properties of nanolayered composites. However, the effect of complexions features (e.g...Thermodynamically stable and ultra-thin “phase” at the interface, known as complexions, can significantly improve the mechanical properties of nanolayered composites. However, the effect of complexions features (e.g., crystalline orientation, crystalline structure and amorphous composition) on the plastic deformation remains inadequately investigated, and the correlation with the plastic transmission and mechanical response has not been fully established. Here, using atomistic simulations, we elucidate the different complexions-dominated plastic transmission and mechanical response. Complexions can alter the preferred slip system of dislocation nucleation, depending on the Schmid factor and interface structure. After nucleation, the dislocation density exhibits an inverse correlation with the stress magnitude, because the number of dislocations influences the initiation of plastic deformation and determines the stress release. For crystalline complexions with different structures and orientations, the ability of dislocation transmission is mainly dependent on the continuity of the slip system. The plastic transmission can easily proceed and exhibits relatively low flow stress when the slip system is well-aligned. In the case of amorphous complexions with different compositions, compositional variations impact the atomic percentage of shear transformation zones after loading, resulting in different magnitudes of plastic deformation. When smaller plastic deformation is produced, less stress can be released contributing to higher flow stress. These findings reveal the role of the complexions on plasticity behavior and provide valuable insights for the design of nanolayered composites.展开更多
The method combining the function transformation with the auxiliary equation is presented and the new infinite sequence complexion solutions of a class of nonlinear evolutionary equations are constructed. Step one, ac...The method combining the function transformation with the auxiliary equation is presented and the new infinite sequence complexion solutions of a class of nonlinear evolutionary equations are constructed. Step one, according to two function transformations, a class of nonlinear evolutionary equations is changed into two kinds of ordinary differential equations. Step two, using the first integral of the ordinary differential equations, two first order nonlinear ordinary differential equations are obtained. Step three, using function transformation, two first order nonlinear ordinary differential equations are changed to the ordinary differential equation that could be integrated. Step four, the new solutions, B?cklund transformation and the nonlinear superposition formula of solutions of the ordinary differential equation that could be integrated are applied to construct the new infinite sequence complexion solutions of a class of nonlinear evolutionary equations. These solutions are consisting of two-soliton solutions, two-period solutions and solutions composed of soliton solutions and period solutions.展开更多
When exposed to moderate to high temperatures,nanomaterials typically suffer from severe grain coarsening,which has long been a major concern that prevents their wider applications.Here,we proposed an effective strate...When exposed to moderate to high temperatures,nanomaterials typically suffer from severe grain coarsening,which has long been a major concern that prevents their wider applications.Here,we proposed an effective strategy to inhibit grain coarsening by constructing grain boundary(GB)complexions with multiple codoped dopants,which hindered coarsening from both energetic and kinetic perspectives.To demonstrate the feasibility of this strategy,multiple selected dopants were doped into a ZrO_(2)-SiO_(2)nanocrystalline glass ceramic(NCGC)to form GB complexions.The results showed that NCGC was predominantly composed of ZrO_(2)nanocrystallites(NCs)distributed in an amorphous SiO_(2)matrix.Ultrathin layers of GB complexions(~2.5 nm)were formed between adjacent ZrO_(2)NCs,and they were crystalline superstructures with co-segregated dopants.In addition,a small amount of quartz solid solution was formed,and it adhered to the periphery of ZrO_(2)NCs and bridged the adjacent NCs,acting as a“bridging phase”.The GB complexions and the“bridging phase”synergistically enhanced the coarsening resistance of ZrO_(2)NCs up to 1000°C.These findings are important for understanding GB complexions and are expected to provide new insights into the design of nanomaterials with excellent thermodynamic stability.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U23A20543,52071124)the Natural Science Foundation of the Hebei Province(No.E2021202135).
文摘Thermodynamically stable and ultra-thin “phase” at the interface, known as complexions, can significantly improve the mechanical properties of nanolayered composites. However, the effect of complexions features (e.g., crystalline orientation, crystalline structure and amorphous composition) on the plastic deformation remains inadequately investigated, and the correlation with the plastic transmission and mechanical response has not been fully established. Here, using atomistic simulations, we elucidate the different complexions-dominated plastic transmission and mechanical response. Complexions can alter the preferred slip system of dislocation nucleation, depending on the Schmid factor and interface structure. After nucleation, the dislocation density exhibits an inverse correlation with the stress magnitude, because the number of dislocations influences the initiation of plastic deformation and determines the stress release. For crystalline complexions with different structures and orientations, the ability of dislocation transmission is mainly dependent on the continuity of the slip system. The plastic transmission can easily proceed and exhibits relatively low flow stress when the slip system is well-aligned. In the case of amorphous complexions with different compositions, compositional variations impact the atomic percentage of shear transformation zones after loading, resulting in different magnitudes of plastic deformation. When smaller plastic deformation is produced, less stress can be released contributing to higher flow stress. These findings reveal the role of the complexions on plasticity behavior and provide valuable insights for the design of nanolayered composites.
文摘The method combining the function transformation with the auxiliary equation is presented and the new infinite sequence complexion solutions of a class of nonlinear evolutionary equations are constructed. Step one, according to two function transformations, a class of nonlinear evolutionary equations is changed into two kinds of ordinary differential equations. Step two, using the first integral of the ordinary differential equations, two first order nonlinear ordinary differential equations are obtained. Step three, using function transformation, two first order nonlinear ordinary differential equations are changed to the ordinary differential equation that could be integrated. Step four, the new solutions, B?cklund transformation and the nonlinear superposition formula of solutions of the ordinary differential equation that could be integrated are applied to construct the new infinite sequence complexion solutions of a class of nonlinear evolutionary equations. These solutions are consisting of two-soliton solutions, two-period solutions and solutions composed of soliton solutions and period solutions.
基金the financial support of the National Natural Science Foundation of China(No.52102084)the Natural Science Foundation of Hunan Province(No.2022JJ30718)Kathryn Grandfield acknowledges funding from the Natural Sciences and Engineering Research Council of Canada(NSERC)discovery grant and research chair programs.
文摘When exposed to moderate to high temperatures,nanomaterials typically suffer from severe grain coarsening,which has long been a major concern that prevents their wider applications.Here,we proposed an effective strategy to inhibit grain coarsening by constructing grain boundary(GB)complexions with multiple codoped dopants,which hindered coarsening from both energetic and kinetic perspectives.To demonstrate the feasibility of this strategy,multiple selected dopants were doped into a ZrO_(2)-SiO_(2)nanocrystalline glass ceramic(NCGC)to form GB complexions.The results showed that NCGC was predominantly composed of ZrO_(2)nanocrystallites(NCs)distributed in an amorphous SiO_(2)matrix.Ultrathin layers of GB complexions(~2.5 nm)were formed between adjacent ZrO_(2)NCs,and they were crystalline superstructures with co-segregated dopants.In addition,a small amount of quartz solid solution was formed,and it adhered to the periphery of ZrO_(2)NCs and bridged the adjacent NCs,acting as a“bridging phase”.The GB complexions and the“bridging phase”synergistically enhanced the coarsening resistance of ZrO_(2)NCs up to 1000°C.These findings are important for understanding GB complexions and are expected to provide new insights into the design of nanomaterials with excellent thermodynamic stability.
