A gradually heated bed warps less than a rapidly heated bed. Or any metal really. Including the gantry.
Heres a good AI explanation, but its been common knowledge in the 3d printing world for a long time…until now.
Uneven Heating and Thermal Stresses:
When aluminum is heated rapidly, the outer surfaces heat up faster than the interior. This creates a temperature difference, causing the outer layers to expand more than the inner layers. This uneven expansion generates thermal stresses within the material.
“Locking” Thermal Strains:
These thermal stresses can become “locked” in the material during the cooling process, especially if the cooling is also rapid. These locked-in stresses can be slowly released during subsequent processing or use, leading to delayed warping or deformation.
Slow Heating for Even Distribution:
Slow heating allows the heat to penetrate the material more gradually, ensuring a more uniform temperature distribution. This reduces the temperature differences and minimizes the buildup of thermal stresses.