Active control of heat induced deformation in a laser deposition process

This paper presents results of ongoing research that addresses possible geometric inaccuracies and structural deficiencies resulting from nonuniform heating and cooling of parts fabricated or repaired using laser powder deposition. An active-control method is investigated, in which piezoelectric (and/or mechanical) actuators provided on the substrate are used sequentially to deform and un-deform a substrate through deposition with the goal of minimizing the residual deformations/stresses in the part. Different actuation configurations are considered, and results based on linear theory are discussed. Initial experimental work is also described. Results to date indicate that the approach could be used to advantage in certain types of builds for active control/reduction of residual deformations/stresses in laser deposited parts.