SBIR-STTR Award

This project proposes the use of non-imaging optical measurement to discern the weld pool oscillations occurring during electron beam deposition, and thereby to infer the weld pool size. By knowing this weld pool size, it is possible to control the e-beam deposition process by suitably regulating heat input, wire feed rate, etc to ensure a consistent depth of penetration. This approach has the advantage of being simple, based on only one sensor, and capable of rapid real-time response. Phase I will investigate the ability of the proposed sensing approach to see weld pool oscillations during e-beam deposition and to distinguish between the signatures of nominal and off-nominal conditions. Phase II will then develop a control scheme based on these in-process measurements. The project team has considerable experience monitoring and controlling arc welding processes using similar approaches and will work with both end udders as well as e-beam machine experts to successfully implement the approach proposed herein.

Benefit:
successful execution of this work will result in a commercially viable system for monitoring and control of electron beam depositon processes, which will benefot a wide range of commercial and defense aerospace applicatoins initially, as well as other discrete parts manufacture.

Keywords:
Monitoring And Control, In-Process Quality Assurance, Welding, Electron Beam, Materials Deposition, Weld Pool Oscillations, Aerospace Manufacturing

Electron Beam Direct Manufacturing (EBDM) has the potential to significantly reduce cost and lead times for such DoD systems as the F-35, if closed loop process control can be implemented. This effort outlines a pragmatic yet effective means of achieving this closed loop control, one that will expand the realm of applications for EBDM significantly. The approach described herein uses commercial off the shelf (COTS) sensors, but has significant process knowledge and process intelligence embedded into a stand-alone process monitoring and control device. No real-time sensors reside in the chamber, thereby greatly reducing the complexity of the interfacing tasks. This current effort will prove the efficacy of this sensing and control approach, but will also demonstrate the technique on a prototypical part mockup that has some common geometric features with actual F-35 parts. Although initially targeted to benefit the F-35, the closed loop system we have proposed herein has very broad applications to virtually any critical component fabrication including aerospace, conventional munitions, and naval applications.

Benefit:
This project will result in dramatic improvements in aircraft and aeroengine prototyping, rapid product development, and even LRIP – low rate initial production. Also the associated lead times for flight hardware will drop from over one year to less than three months for new designs. The logistical implications for both OEM and spare parts are tremendously favourable. It is anticipated that such tremendous cost, lead time and productivity benefits will also accrue to other titanium parts for other defence applications as well as commercial aviation, or to any application that utilizes large, high quality titanium parts. Also, the same methodology could be adapted to steel, monel and aluminium bronze parts, thereby similarly revolutionizing the supply chain for critical naval spares.

Keywords:
Electron Beam Direct Manufacturing -Ebdm, Titanium, F-35, Aerospace Hardware, Closed Loop Process Control