Additive Manufacturing of Metals: Equipment, Instrumentation and In-Situ Process Monitoring: Novel Instrumentation
Program Organizers: Ulf Ackelid, Freemelt AB; Ola Harrysson, North Carolina State University; Joy Gockel, Colorado School Of Mines; Sneha Prabha Narra, Carnegie Mellon University
Wednesday 3:00 PM
October 20, 2021
Room: A121
Location: Greater Columbus Convention Center
Session Chair: Joy Gockel, Colorado School of Mines
3:00 PM Invited
Ultrasonics for Monitoring Melt Pool Dynamics and Solidification: Christopher Kube1; Jared Gillespie1; Tao Sun2; Cang Zhao3; Niranjan Parab4; Anthony Rollett5; 1The Pennsylvania State University; 2University of Virginia; 3Tsinghua University; 4Intel Corporation; 5Carnegie Mellon University
In metallic additive manufacturing (AM), melt pools and subsequent solidification strongly influence the final part quality. Thus, understanding melt pool dynamics relative to process parameters pushes manufacturing toward higher quality and better performing parts than currently possible. Modeling and in situ monitoring of melt pools are vital research activities for improved understanding. This presentation reports progress on the development of an ultrasonic technique for melt pool monitoring. As ultrasound can propagate within solids, the technique displays promise in providing in situ volumetric information, which can compliment currently used techniques for observing the melt pool from above. In situ simultaneous ultrasound/high-speed X-ray imaging on conduction and keyhole mode melt pools in Al6061 will be reported and discussed. The X-ray comparison provides important ground truth for ultrasound signal interpretation and aids in the planned transition of the ultrasonic technique into AM processes.
3:40 PM
Functionally Graded Material Development by Leveraging Ultrasonic Grain Refinement in Additive Manufactured Nickel 718: Nathaniel McNees1; Satish Rajaram2; Mark Warchol2; Brian Wisner1; 1Ohio University; 2Texas Research Institute-Austin
Metal Additive Manufacturing processes are increasingly attractive because of their ability to produce complex geometry and unique material properties. Often additive manufacturing relies on trial and error to achieve the optimum build parameters which can still result in significant property variation within a single build plate let alone across multiple builds. Improved build consistency and reduced grain structure is demonstrated by leveraging Ultrasonic irradiation during the build of Selectively Laser Melted (SLM) Nickel 718. Improved micro-structure and properties are shown using scanning electron microscopy and mechanical testing methods. Moreover, by varying the ultrasonic energy and the typical print parameters including laser power and scan speed, the potential for generating complex functionally graded materials is demonstrated.