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This paper emphasis has researched the effect of particles scattering, surrounding thickness, heat treatment temperature and etc on microstructure, mechanics properties and macrostructure under different electric field of Ni/TiO2, Ni/TiO2/PAn Particles ER fluid, It is found that particles scattering, surrounding thickness, heat treatment temperature have major effect on shear stress and chain of particles.

In order to obtain the directional microstructure of different supersaturation and growing velocity, three simulations is calculated with different initial temperature. When the initial temperature is 1576K, and the supersaturation and growing velocity are smaller. The average space length of columnar crystals is bigger, and microsegregation is smaller. when the initial temperature is 1574K, the supersaturation and growing velocity increase. The average space length of columnar crystals decreases, and microsegregation increase; when the initial temperature falls to 1566K, the supersaturation and growing velocity reach 1.176 and 3.238 cm per second. The microsegregation decreases rapidly. The average space length of columnar crystals is the smallest. The solute curve of columnar crystal is like a “U” figure. When the growing velocity is bigger than VA, the phenomenon of solute trapping takes place.

In this study W was found to have strong effects on solidification structure of the binary alloy. Based 0.5 W0、W0 and 1.5W0 base W0, three conditions with free energy base W equal to 0.5 W0, W0 and 1.5W0 respectively were computed. The results showed that the variation of energy base contributed a lot to the development of side branches of equiaxed dendrite structures, the lower W, the more developed side branches, the higher W, the more restrained side branches. Furthermore, the effects of boundary layer thickness δ on solidification structures were also studied. It is found that when the layer thickness δ is as small as Δx/0.94, computational errors occurred at the base of the dendrite and when the layer thickness δ is as big as Δx/0.54, some irreal phenomena, such as coarsened dendrite trunks and maladjusted side branches, could be caused. Further study on space step Δx showed that bigger space steps made higher computational errors. It is given that the relationships among phase-field perturbation, space step and solidification structure.