Real-time Control for Improving Materials Processing Capabilities:
Examples from e-beam deposition of precision optical coatings & plasma spray of TBC & fuel cells.
MIT SEMINAR SERIES IN MANUFACTURING AND
PRODUCTIVITY
Place: Room 33-116 Time: 12:00 P.M. Tuesday, October 03, 2006
Professor Michael Gevelber
Boston University, Department of Manufacturing Engineering
Materials processing problems are increasingly more difficult as we seek to achieve greater control over material microstructure while also improving production performance. Our research is focused on applying a controls based approach to develop enhanced materials processing capabilities. The results of our real-time control for e-beam deposition and plasma spray will be discussed.
Optical coatings are an enabling technology for many important applications in telecommunications, defense, and high energy lasers. Although electron beam vacuum deposition has long been used to manufacture these coatings, more stringent coating requirements require a greater level of thickness and composition control with optimized production performance (rate, yield, and variability). We present our research results that lead to developing enhanced e-beam coating capabilities demonstrated on commercial scale systems.
Plasma spray is an importing coating technology due to its ability to economically engineer ceramic coating structure for important energy applications. We have developed a feedback control system for plasma spray that reduces variations and provides a greater ability to engineer coating structure for advanced thermal barrier coatings (TBC) and fuel cells. The limitations and performance capabilities of both feed-forward and real-time control are evaluated. Important system characteristics needed to develop such controllers are discussed including dominant non-linearities, input-output cross-coupling, particle state distributions, and sensor issues.
