You are here

Non Destructive Evaluation (NDE) of Production Additive Manufactured Parts

Description:

TECHNOLOGY AREA(S): Materials, Materials, Air Platform, Air Platform, Space Platforms, Space Platforms

OBJECTIVE: Develop an innovative process for rapidly evaluating the suitability of 3D printed production metal parts through non-destructive means.

DESCRIPTION: This topic seeks to determine the statistical correlation between defects in 3D printed metal parts which result in a reduction in strength, toughness or fatigue life, and non-destructive performance parameters such as deflections from sub-yield forces, acoustic or electrical resonance or other easily testable metrics.Innovative methods are sought to correlate nondestructive tests with tests-to-failure for an assortment of representative part designs to determine if deviations from the predicted response to nondestructive inputs can be used to detect defects which would cause the failure of a part in service.Additively manufactured prints of metal parts contain voids and intra-granular impurities which are difficult to detect in the finished part.Computerized Tomography (CT) scans are currently used to detect internal voids but require expensive equipment, substantial time, and experienced operators to run.It is also difficult to properly evaluate CT scans of complex parts with irregular overlapping structures.To facilitate certification of 3D printed flight hardware, innovative NDE tests which are fast and work well on irregular complex shapes are sought.

PHASE I: Identify one or more NDE technique(s) which have a high likelihood of detecting internal voids and defects, resulting in lower than expected failure resistance or fatigue life.Print multiple test bars using a common aerospace material, some with known defects and some without, and demonstrate that some combination of NDE techniques are capable of detecting the flawed parts. Test the printed samples to failure.Document results including the NDE methodology, correlation between the NDE results and the ultimate strength, and describe plans for Phase II.

PHASE II: Demonstrate the ability to detect internal flaws in multiple complex parts using cheap, fast NDE techniques.Print a large number of complex parts with assorted internal flaws and demonstrate the correlation between NDE results and the ultimate strength at failure with high statistical confidence.Document the minimum detectable flaw sizes and densities and their impact on ultimate strength and how this is affected by part shape and complexity.Demonstrate the ability of the NDE to validate the quality of a 3D print of prototype flight hardware with the same confidence as CT scans.

PHASE III: Develop necessary NDE performance specifications for 3D printed part(s) of a government flight hardware system.Demonstrate the screening of production quantities of the 3D printed parts using the developed methodology with sufficient confidence to permit flight certification of accepted parts.Transition the methodology to applications in aviation, maritime, and ground vehicles.

KEYWORDS: NDE, 3D printing, certification, production, Additive Manufacturing

References:

1. Consortium for Additive Manufacturing Materials Roadmap http://www.cimp-3d.org/documents/camm_roadmap.pdf2. Nondestructive Testing of Additive Manufactured MetalParts Used in Aerospace Applications https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180001858.pdf

US Flag An Official Website of the United States Government