NDI System for Quantification of Subsurface Residual Stress in the Laboratory
Navy SBIR FY2015.2

Sol No.: Navy SBIR FY2015.2
Topic No.: N152-091
Topic Title: NDI System for Quantification of Subsurface Residual Stress in the Laboratory
Proposal No.: N152-091-0195
Firm: Radiation Monitoring Devices, Inc.
44 Hunt Street
Watertown, Massachusetts 2472
Contact: Stuart Miller
Phone: (617) 668-6928
Web Site: http://www.rmdinc.com
Abstract: The goal of the proposed research is to develop a non-destructive method for subsurface residual stress measurement in turbo-machinery components. Neutron diffraction techniques have a proven ability to determine residual stresses at significant depths, however implementation of these techniques has been limited to specialized facilities such as the High Flux Isotope Reactor (HFIR) neutron at Oak Ridge National Lab. Advances in laboratory based neutron generators have now created the possibility to implement some of these techniques in laboratory and/or production environments. We plan to exploit the improved capabilities of these generators to realize a practical method that will enable determination of residual stresses throughout large components or bulk materials. The proposed non-destructive evaluation method will combine advantages of conventional in-situ neutron diffraction with energy selective neutron imaging to reveal microstructural information related to the lattice spacing such as phase, texture, and strain. The Phase I program will demonstrate feasibility of our novel method whereas the Phase II program will logically extend Phase I research to implement a practical system. To successfully develop this challenging but highly rewarding technology, we have formed a strong consortium that includes a world renowned expert in experimental measurements of residual stress using neutron and x-ray techniques and an OEM for turbo-machinery, which will effectively address current needs of the Navy.
Benefits: The evaluation technique we propose is a viable method for subsurface residual stress measurements in turbo-machinery components in a laboratory environment. The development of this technology not only will address immediate needs of the Department of Defense, but also will have substantial impact on non-destructive testing in general. In addition, the novel detection system to be developed under this program will have immediate benefits in applications where dynamic imaging is critical, including biomedical engineering, medical imaging, basic research, and such neutron diffraction applications materials engineering and drug developments. Non-destructive techniques are widely used in industry and as such the proposed development will have a significant application potential. Residual stress measurement systems are specifically needed in numerous industrial and research applications where X-rays are inadequate in terms of penetrating power. The neutron based techniques outlined here are applicable to automotive industry, aerospace industry, in characterizing structural integrity of buildings/bridges etc. Also, neutrons are increasingly used as a probe in medical diagnostics and imaging, where the detector systems developed under this program will play a significant role.