Sharif Digital Repository

The recrystallization behavior of a commercial nickel-cobalt base superalloy, AEREX 350, is investigated by means of hardness test, X-ray diffraction, and microscopy. It is found that the alloy resists recrystallization up to a high temperature of 1025 °C. Recrystallized grains are readily formed at grain boundaries below this temperature; however, the growth of these new grains is inhibited by Widmanstätten η particles having coherent facets with the nickel matrix (γ). The passage of the recrystallization front results in coherency loss and consequently dissolution of the η platelets. Recrystallization proceeds with a discontinuous precipitation of the η phase behind the moving boundary  

The main purpose of this paper is modeling and simulation of in-situ releasing of smart nano-sized core-shell particles at the water-oil interface during polymer flooding. During the polymer flooding process, when these nano-particles reach the water-oil interface, migrate to the oil phase and the hydrophobic layer of them dissolves in this phase. After dissolution of this protective nano-sized layer, the hydrophilic core containing a water-soluble ultra high molecular weight polymer diffuses back into the water phase and with dissolving in this phase, dramatically increases viscosity of flooding water in the neighborhood of the water-oil interface. In this study, two different... 

In this paper, a new computational technique is presented for the modeling of moving boundaries in large plastic deformations based on an enriched arbitrary Lagrangian-Eulerian finite element method. An Arbitrary Lagrangian-Eulerian (ALE) technique is employed to capture the advantages of both Lagrangian and Eulerian methods and alleviate the drawbacks of mesh distortion in Lagrangian formulation. An enriched finite element method is implemented based on the extended FEM technique to capture the arbitrary interfaces independent of element boundaries. The process is accomplished by performing a splitting operator to separate the material (Lagrangian) phase from the convective (Eulerian)...