Three-Dimensional Mathematical Modeling and Numerical Simulation of Billet Shape in Spray Forming Using a Scanning Gas Atomizer

摘要

A three-dimensional shape model, tracing the coordinates of the moving surface of a growing billet spray formed by a scanning gas atomizer, has been developed in this study. New mesh generation and surface smoothing algorithms for the growing billet, as well as shading algorithms, are incorporated into the model for accurate prediction of the shape and dimensions of the billet during spray forming. Mass flux distribution profiles of the spray generated by the scanning atomizer under different spraying conditions have been revealed for the shape modeling. Geometrical evolution of the billet in spray forming has been investigated based on analysis of the scanning mechanism of the atomizer. The shape modeling has been validated by different numerical algorithms and experimental investigations. Finally, the influence of processing conditions on the shape and dimensions of spray-formed deposits have been simulated and discussed. Near-net-shaped preforms with triangular or square cross section, other than the usual circular cross section, are expected to be produced under appropriate spray forming conditions.