The results of a molecular dynamics(MD)simulation are presented for CaSiO3 melt under an electric field.The two-body interaction potential is adopted in the simulation,with parameters chosen so that the calculated sta...The results of a molecular dynamics(MD)simulation are presented for CaSiO3 melt under an electric field.The two-body interaction potential is adopted in the simulation,with parameters chosen so that the calculated static structure is consistent with results of high temperature x-ray experiments.It is found that the MD results for the heat capacity at constant volume,the self-diffusion coefficient and the electrical conductivity change greatly when the electric field is over 500 MV/m.Discussion is given on these results,together with the frequency-dependent electrical conductivity.展开更多
The main objective is to provide an evidence of spatial dependence of mechanical responses of a heterogeneous aluminum brazed joint re-solidified clad, and to confirm a sufficient sensitivity of a nano-indentation—lo...The main objective is to provide an evidence of spatial dependence of mechanical responses of a heterogeneous aluminum brazed joint re-solidified clad, and to confirm a sufficient sensitivity of a nano-indentation—load curve method for identifying the dependence. Topological features of a network of solidification microstructures(α phase and eutectic), formed during quench in a brazing process of aluminum alloy, influence significantly dynamic mechanical responses of resulting heterogeneous material. Nano/micro indentation depth vs load characteristics of differing phases suggest a spatially sensitive mechanical response of a re-solidified fillet in the joint zone. Hence, a spatial distribution, pattern formations and other morphological characteristics of microstructures have a direct impact on an ultimate joint integrity. Topology-induced variations of indentation—load curves was presented. A hypothesis involving microstructures’ spatial distribution vs mechanical response was formulated.展开更多
基金Supported by the National Natural Sciences Foundation of China under Grant Nos.59874016 and 59832080the Shanghai Research Center for Advanced Materials under Grant No.98JC14018Shanghai Sciences Foundation of Youth.
文摘The results of a molecular dynamics(MD)simulation are presented for CaSiO3 melt under an electric field.The two-body interaction potential is adopted in the simulation,with parameters chosen so that the calculated static structure is consistent with results of high temperature x-ray experiments.It is found that the MD results for the heat capacity at constant volume,the self-diffusion coefficient and the electrical conductivity change greatly when the electric field is over 500 MV/m.Discussion is given on these results,together with the frequency-dependent electrical conductivity.
文摘The main objective is to provide an evidence of spatial dependence of mechanical responses of a heterogeneous aluminum brazed joint re-solidified clad, and to confirm a sufficient sensitivity of a nano-indentation—load curve method for identifying the dependence. Topological features of a network of solidification microstructures(α phase and eutectic), formed during quench in a brazing process of aluminum alloy, influence significantly dynamic mechanical responses of resulting heterogeneous material. Nano/micro indentation depth vs load characteristics of differing phases suggest a spatially sensitive mechanical response of a re-solidified fillet in the joint zone. Hence, a spatial distribution, pattern formations and other morphological characteristics of microstructures have a direct impact on an ultimate joint integrity. Topology-induced variations of indentation—load curves was presented. A hypothesis involving microstructures’ spatial distribution vs mechanical response was formulated.
