Thermal effect on clad dimension for laser deposited Inconel 718

Additive manufacturing of components made of nickel-based and high strength materials that endure extreme environments, such as Inconel 718, is gaining traction in aerospace and automotive industries. However, one of the remaining challenges of laser deposited alloys is the volume change of the clad during a build, leading to warping, compromised dimensional integrity of the final part, and an increase in surface roughness. In addition, there has been no work in the prediction and control for volume change of localized areas within a laser deposited component. The dimensional integrity of a completed laser deposited structure is dependent on the uniformity of each individual clad track, with high variability in thermal history and clad height. The approach in this paper is the use of an in-situ infrared camera to capture the thermal history and determine the unique solidification rate of each localized point of each clad. Clad height measurements various points of the dads relative to the tool path were used to establish a relationship between process parameters, solidification rate and the volume change of the clad that verify analytical thermal models in the literature. Expanding these relationships to more complex build geometries, different laser deposited materials and a wider variety of processing conditions will allow for a better understanding, and therefore control, of the laser deposition process for more ubiquity of additive manufacturing in industry. (C) 2017 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.