Mathematical Model for Metal Transfer Study in Additive Manufacturing with Electron Beam Oscillation

A computer model has been developed to investigate the processes of heat and mass transfer under the influence of concentrated energy sources on materials with specified thermophysical characteristics, including temperature-dependent ones. The model is based on the application of the volume of fluid (VOF) method and finite-difference approximation of the Navier–Stokes differential equations formulated for a viscous incompressible medium. The “predictor-corrector” method has been used for the coordinated determination of the pressure field which corresponds to the continuity condition and the velocity field. The modeling technique of the free liquid surface and boundary conditions has been described. The method of calculating surface tension forces and vapor recoil pressure has been presented. The algorithm structure is given, the individual modules of which are currently implemented in the Microsoft Visual Studio environment. The model can be applied for studying the metal transfer during the deposition processes, including the processes with electron beam spatial oscillation. The model was validated by comparing the results of computational experiments and images obtained by a high-speed camera

Simulation of heat transfer and metal flow in wire-based electro beam additive manufacturing

The urgency of mathematical model development for wire-based electron-beam additive manufacturing process analysis is shown. The procedure of solving heat equation for metal in the solid phase and the Navier-Stokes equations in the liquid phase, based on the use of the finite-difference method and the predictor-corrector procedure is described. An algorithm for numerical approximation of free melt surface motion, using the concept of the volume of fluid (VOF), is described as well. A numerical algorithm for surface tension force calculating is proposed. The model described above was realized as a program in the Microsoft Visual Studio environment. Series of computational experiments were carried out to calculate metal flow during deposition with the use of 316L steel wire. The results of experiments are compared with experimental data

High-heat flux tests of fusion materials with stationary plasma in the PLM device

The PLM plasma device was constructed for high heat flux tests of fusion plasma-facing materials and in-vessel components of a fusion reactor. The ITER-grade tungsten samples were irradiated with steady-state plasma in PLM. The combined tests of ITER-grade tungsten samples with an e-beam load of 40MW/m(2) and stationary steady-state plasma load of similar to 1 MW/m(2) led to erosion, cracking, and nanostructured "fuzz" structure growth on the material surface. The capillary porous system of liquid tin was tested with steady-state plasma in PLM during similar to 200 min demonstrating sustainability under high heat plasma load. Lithium materials deposited in the T-10 tokamak during experiments with lithium capillary-porous system have been irradiated with stationary steady-state plasma in PLM to test the evolution of the deposits under long-term plasma load