Additive manufacturing (AM), also known as 3D printing, is revolutionizing how various structural components are manufactured. Laser Powder Directed energy deposition (LP-DED), which is one type of metal AM processes, utilizes a concentrated laser source and metal powders to achieve layer-by-layer deposition of materials. Although significant progresses have been made for the development of DED processes and materials, little work has been done for in-situ nondestructive testing and quality control. In this study, a suit of in-situ nondestructive testing (NDT) and process control techniques are developed, including (1) real-time melt pool depth estimation and control using coaxial infrared camera, (2) real-time porosity inspection based on transient thermoreflectance measurement using femtosecond laser, (3) in-situ mechanical properties estimation based on noncontact ultrafast ultrasonic measurement, (4) real-time porosity reduction and microstructure improvement using a repetitive Nd:YAG pulse laser, and (5) track-wise geometry monitoring using laser line scanner. 

Metal additive manufacturing methods are increasingly the method of choice when relatively small batches of components with complicated geometries are needed. Although many metal additive manufacturing methods have been proposed, the most popular methods involve deposition and fusion of metal, using energy sources such as lasers, in thin layers to build the component. Extensive studies carried out to date have shown that the dynamics of the melt pool has a strong influence on the microstructure, and hence the quality of the component being built. Failure to control the process parameters within a very narrow window can result in flaws such as pores and keyholes. This presentation describes a new electromagnetic method that is being developed for controlling the dynamics of the melt pool during the deposition process to broaden the process control window. Simulation results obtained to date, using coupled multiphysics models, demonstrate the ability of this approach to control the dynamics of the melt pool. 

Satish S. Udpa serves as an Interim President Emeritus and University Distinguished Professor Emeritus at Michigan State University (MSU). Prior to this, he served in many academic and administrative capacities at MSU including Interim President, Executive Vice President for Administration, Dean of the College of Engineering, Chair of the Department of Electrical and Computer Engineering and University Distinguished Professor. He also served as the President of the Michigan State University Foundation. Dr. Udpa was the Whitney Professor of Electrical and Computer Engineering at Iowa State University and a faculty member at Colorado State University before joining Michigan State University in 2001.