| Abstract Scope |
Presently, almost all the alloys used by metallic additive manufacturing (AM) were developed for conventional fabrication. Most of them, especially wrought alloys, are not manufacturable by AM. During AM process, residual stresses due to solidification shrinkage and thermal gradient build up layer by layer, and finally leads to failure (cracking). One way to fundamentally improve the manufacturability of those legacy alloys is grain refinement. In this work, we will use phase-field method to study the grain refinement for AM. The competition between nucleation and growth with the presence of multiple nucleant particles will be simulated. The mechanism of grain refinement under the rapid solidification and the limiting factors, such as nucleant particle size, solute diffusion, and thermal properties of matrix, will be discussed. |