Organization: W. M. Keck Center for 3D Innovation, The University of Texas at El Paso, El Paso, TX

Project Date: June 2011 – January 2013

Background: An infrared (IR) imaging system was implemented in an Arcam A2 EBM system providing another level of control for the EBM process that could lead to rapid certification of flight-ready parts. The scope of the project was to incorporate IR thermal imaging in the fabrication process of EBM to provide layer-by-layer feedback and ensure quality products were produced in the Arcam A2 metal AM system. Layer-by-layer build surface temperature profiles were imaged and analyzed, providing information that was used to modify build parameters (i.e. beam current, beam speed, focus offset, heating times, etc.) for proceeding build layers.

Objective: To improve control and feedback of the additive manufacturing process electron beam melting (EBM) for better part quality and uniform production in manufacturing.

My Position: Graduate Researcher

My Role: As the lead researcher, this project was my graduate research work that constituted my master’s thesis. I was in charge of integrating the IR imaging system, programming it to acquire data at set process steps, establishing calibration procedures to acquire temperature data within an appropriate level of certainty, and performing closed-form solutions using fundamental heat transfer equations to acquire the target material’s emissivity.

Technical Fundamentals: Control Systems, Heat Transfer, Material Science, Mechanics of Materials

Skills: Automation, root-cause analysis, software programming, data acquisition and analysis, material testing, additive manufacturing, heat transfer analysis, computer-aided design (CAD), and statistical process control.

Technology Tools: LabVIEW, MATLAB, SolidWorks, Arcam A2 electron beam melting system, FLIR IR Camera, National Instruments data acquisition (DAQ) controller, pneumatic systems, thermocouples

ARCHITECTURE FOR IR FEEDBACK CONTROL IN ARCAM A2 SYSTEM
CAD RENDERING OF THE ARCAM A2 VACUUM CHAMBER WITH IR CAMERA
NI CRIO 9074 MODULAR CONTROLLER
BLOCK DIAGRAM – IMAGE ACQUISITION.VI (MODULE ‘A3’ DIGITAL OUTPUT/VOLTAGE SIGNAL - “TRUE” STATE) [1/4]
VACUUM CHAMBER WITH ADDITIONAL THERMOCOUPLES PUT IN PLACE FOR HEAT SHIELD TEMPERATURE MEASUREMENT
IR IMAGE OF CU PART WITH OBSERVED POROSITY OR UN-MELTED PARTICLES

Results / Outcome: A primary objective of this research was to develop a method for obtaining accurate solid metal surface temperatures in the particle bed. The development of a thermal-imaging feedback-control system integrated into the Arcam A2 system has provided the ability to measure temperatures of the surface bed – a state of the art capability that can prove to produce valuable results.