In-Process and Final Non-destructive Inspection Methods of Additive Manufactured (AM) Simulated Aerospace Critical Parts

ABSTRACT: This project focuses on improving Americas manufacturing capability. The proposed innovation is an in-process structural integrity inspection system applicable to additive manufacturing (AM) systems. The basis for this system is the detection, tracking, and physics-based interpretation of the surface temperaturetime- space profile of each laser sintered zone. The temperature detection instrumentation proposed is a combination of a moderate cost long wave thermography camera, together with a shortwave infrared interferometer applied through a process known as Optical Coherence Tomography (OCT). In each case, the optical instrument will be coupled with physical optics (including lenses) that allow focus and enlargement of the laser heat affected zone. Software will curve-fit the temperature field of each layer, and its change over time, comparing this to analytical predictions for a CAD-modelled component being manufactured. Deviation statistics will be calculated, and compared to deviation amount and characteristics that signify insufficient bonding integrity or other defects (e.g. improper constituency of a particular grain of material). Components that are faulty will be rejected before additional production time is wasted. More importantly, the proposed system will allow the AM manufacturing facility to determine the point in the process where the problem has occurred, allowing on-going process improvement.; BENEFIT: The proposed innovation is expected to significantly advance the state-of-the-art in additive manufacturing inspection systems, while creating the standard for in-process inspection and quantification of structural integrity associated error in aerospace critical components. The anticipated direct benefit of this project is to transform and further develop military depot prototyping, sustainment and production centers. OBIES will provide direct position-related anomaly detection coupled with structural integrity quantification via the OCT technology employed. By defining acceptable error in the production process of aerospace critical components, the foreseen benefit would be to maximize production efforts while minimizing wasted time and material. Furthermore, many other U.S. government agencies would greatly benefit from the industrial production advances that MSIs process would present. Commercial application directly parallels with the proposed innovations advancement of additive manufacturing processes. Virtually any commercial production process either currently using additive manufacturing or that would benefit by employing additive manufacturing technology would capitalize on reduced production costs and times.