British materials researchers have gained detailed insights into the mechanisms of melt solidification in 3D printing. Their simulations reveal how impurities are distributed in the molten metal bath and how microcracks can form as a result.
As Dr. Chinnapat Panwisawas from Queen Mary University of London explains, rapid temperature changes during layer-by-layer melting often lead to material stresses and undesirable effects such as pore formation. His team has now been able to clarify the complex processes involved in the solidification of molten metal using computer-aided modeling.
A certain effect called “solute trapping” plays a key role. Impurities accumulate in some areas of the solidification front, which leads to local structural changes. This can promote cracks and other defects that reduce the strength of printed components.
According to the researchers, undesirable effects of solute trapping can be avoided through targeted process adaptation. For example, accelerated solidification could reduce the tendency to crack. The results should help to develop more resistant metal alloys and optimized parameters for additive manufacturing.
The study entitled “Solute trapping and non-equilibrium microstructure during rapid solidification of additive manufacturing” was published in Nature Communications.