Feedforward Laser Power Specification for Uniform Cooling of Thin-Walled Parts Available to Purchase

This paper presents results from ongoing research on thermal-model based feedforward specification of laser power in a laser powder deposition process. The goal of this algorithm is to compute, before deposition of a layer, the laser power sequence and distribution that would produce a desired temperature distribution over that layer. This in turn will enable uniform cooling of the layer and avoid build up of residual stresses. In this paper, results based on a simplified thermal model and second-order spatial discretization are presented. Two types of discretization in the time domain are examined. The matrix-exponential-based discretization is expected to be more accurate at lower laser speeds. The desired laser power sequence and the resulting temperature histories for a prescribed laser speed are discussed within the context of a thin-walled part.