SBIR-STTR Award

IBRs represent a great advance for military aero-engine performance. However increased performance has its price: high manufacturing costs and difficulty with in-service repair. Linear friction welding (LFW) and/or high speed machining have reduced manufacturing costs, but service repairs are still significant cost and technical challenges. Current technologies under development include LFW, laser processing, and electron beam processing. These methods can produce metallurgically acceptable welds but are very costly, complex, and not generally compatible with cellular operations. This proposal involves gas metal arc welding - GMAW -with two important innovations: modern adaptively controlled power supplies and a novel in-process quality assurance (IPQA) method that stabilizes the GMAW welding of titanium enabling superior weld properties, minimal spatter/porosity, and control of fusion zone geometry. This advanced GMAW for Titanium is currently being implemented by us for US Army static structural applications, and therefore initial risk reduction work is already in progress. Furthermore, we have successfully applied this method to high rate GMAW processes in aluminum alloys virtually eliminating porosity and spatter. The successful development of this technology for Ti-IBR weld repair would decrease weld repair costs by an order of magnitude, thereby realizing a truly cost-effective IBR repair allowing wider use of this technology.

Keywords:
Gmaw, Gas Metal Arc Welding, Ibrs, Integrally Bladed Rotors, Weld Repair, In-Process Quality Assurance, Titanium Welding, Advanced Process Monitoring

Integrally Bladed Rotors – IBRs – are an important part of current and future military aeroengines. The use of IBR allows lower weight rotors with decreased drag and improved compressor efficiency. Repair of these parts however is currently problematic. The overarching objective of the Phase II work is to build upon the successful proof of principle conducted in Phase I and to build, test and validate a prototype for Titanium Gas Metal Arc Welding (GMAW) for IBR weld repair. This project will build upon the successful Phase I work by first developing welding parameters for smaller diameter wire enabling even finer weld geometry and hence repairs on smaller areas. Then, a novel monitoring and control methodology known as In – Process quality Assurance – IPQA – will be implemented to sense and control vital aspects of the welding process not possible with current approaches. Lastly, this advanced monitoring and control will be integrated with commercial power supplies to provide a prototype solution that can be transitioned to production in Phase III. Demonstration weld repairs will be made on prototypic mockup parts and metallurgical and mechanical properties will be evaluated to ensure suitability of this procedure for IBRs.

Keywords:
Titanium, Welding Of Titanium, Gas Metal Arc Welding, Gmaw-P, Ibr Weld Repair, Weld Repair Of Flight Hardware, In-Process Quality Assurance, Adaptive