Simulation of HDIs behaviors in the plasma arc cold hearth melting process

A 3D finite element model was established using the software ANSYS to simulate the inclusions trajectories and residence time in refining TiAl alloys during PAM process. The results show that tungsten, molybdenum and niobium inclusions can be removed by the mushy region entrapment, and all of these particles which diameter is larger than 40μm are captured in the pool bottom. The residence time of inclusion depends on the particle density and size. The bigger the inclusion density or the lager the inclusion diameter, the shorter the residence will be. Moreover, the inclusions trajectories and residence time are influenced by the hydrodynamics of the melt. The buoyancy force and the drag force provided by melt drive the inclusion particles moving in the pool.