One of the most common causes of distortion and cracking in metal additive manufacturing is sudden changes in wall thickness. When thin sections abruptly transition into thick areas, heat is absorbed and dissipated unevenly during printing. This creates internal stresses that can warp or even fracture a part, especially during cooling or post-processing.
These problems aren’t always visible until it’s too late. The part may look perfect on the outside but harbor internal tension that leads to deformation during support removal, machining, or heat treatment. That’s why thermal design isn’t just about geometry, it’s about consistency in how mass absorbs and releases energy.
The solution lies in smooth transitions. Using chamfers, radii, or gradual tapers between thin and thick regions spreads the thermal load more evenly, minimizing hotspots and shrink differentials. Fillets, in particular, soften stress concentrations and help the part “flow” better thermally, reducing the likelihood of residual stress buildup.
Simulation tools can also predict where these stress zones may appear and help designers adjust before printing. In some cases, lattice infills or strategic hollowing can replace thick sections entirely, further equalizing thermal mass without compromising strength.
In the end, success isn’t just about printing what you designed, it’s about designing what will print well. Prioritizing thermal flow in your geometry is a foundational step toward repeatable, distortion-free parts.