MWM-Array Inspection of HVOF Coated Landing Gear Components

ABSTRACT: This proposed Phase II SBIR will further demonstrate Nondestructive Inspection (NDI) of coated high strength steel (HSS) landing gear for high priority defects such as grinding burns or other heat damage, cracks, and possibly overloads and other defects. We will continue to advance JENTEK's Meandering Winding Magnetometer Array (MWM-Array) technology - including sensors, multivariate inverse methods and portable instruments. This is a critical need to support the USAF's transition from electrolytic hard chromium coatings (EHC) to the more environmentally benign tungsten carbide-cobalt (WC-Co) and tungsten carbide-cobalt-chromium (WC-Co-Cr) coatings. The goal is to avoid the costly removal of these coatings, producing substantial savings and improving fleet availability. During Phase I, JENTEK worked with the USAF and Delta TechOps to define NDI requirements and we clearly demonstrated feasibility of detecting subsurface cracks and grinding burns in HSS through foils representative of chromium plated on landing gear. Clear indications of the defects of interest were produced; specifically for real cracks under coatings and for EDM notches and grinding burns under representative foils. In the proposed Phase II, we will fabricate and access more representative samples to both develop enhanced capability and demonstrate NDI performance suitable for transition into depot/field use. BENEFIT: If the proposed Phase II is successful, the USAF will have a reliable means for detecting cracks, grinding burns, overloads and other defects in HSS landing gear without removing HVOF and/or other coatings. The capability to inspect through such coatings will result in substantial savings and may improve availability of aircraft for the USAF by avoiding the costly and time-consuming process of coating removal. The developed inspection capability will facilitate the transition from EHC to HVOF WC-Co and WC-Co-Cr coatings, a transition that is also occurring in the commercial aviation community. Thus, we anticipate a substantial commercial demand for this SBIR developed capability.