Papers by Author: M. Asle-Zaeem

Abstract: In this research, we present a method for the embedment of hydroxyapatite (HA) into superplastic Ti6Al4V where the elements of HA and Ti6Al4V diffuse into each other to form a high quality implanted layer. The implantation process into superplastic titanium alloy was divided to two steps; first, the superplastic forming of Ti6Al4V was carried out using high-temperature compression test machine. In the second step, HA was embedded into superplastic Ti6Al4V by using a special designed clamp with an initial compressive load at high temperatures. The EDX and Line Scanning analyses indicate that the resulted film is composed of elements of HA and titanium alloy and due to the diffusion of HA and Ti6Al4V elements into each other, a good embedment is achieved. The elemental diffusion of HA and Ti6Al4V increases by increasing the temperature of the implantation process therefore the thickness of the implanted layer and the hardness of the embedded surface increase with the temperature.

Abstract: Cahn-Hilliard type of phase field model coupled with elasticity is used to derive governing equations for the stress-mediated diffusion and phase transformation in thin films. To solve the resulting equations, a finite element (FE) model is presented. The partial differential equations governing diffusion and mechanical equilibrium are of different orders; Mixed-order finite elements, with C0 interpolation functions for displacement, and C1 interpolation functions for concentration are implemented. To validate this new numerical solver for such coupled problems, we test our implementation on thin film diffusion couples.