Laser Welding Heat Control for Dissimilar AM Parts

The patent applies parameter changes by controlling cooling rates and thermal cycles during laser welding. By adjusting welding parameters (laser power, speed, focus position) and cooling parameters (coolant flow rate, temperature), the thermal history of the weld zone is modified to achieve more uniform grain structure while maintaining strong weld joints between dissimilar additively manufactured parts.

The patent implements local quality by applying selective cooling measures to different regions of the weld joint. The cooling device targets specific zones (such as the heat-affected zone or weld metal) with controlled cooling rates, creating locally optimized microstructures that improve overall mechanical properties while addressing the non-uniform grain structure problem.

The patent applies preliminary action by implementing pre-cooling measures before laser welding. The cooling device is activated prior to laser beam application to establish a controlled thermal baseline, preventing excessive temperature rise that would cause material deformation and equipment damage, while still achieving adequate welding penetration.

The patent converts the harmful ultra-high temperature into a beneficial controlled thermal process. By introducing active cooling during welding, the excessive heat that would normally cause deformation is transformed into a controlled thermal cycle that achieves penetration while maintaining dimensional accuracy and preventing equipment damage.