In Situ, Nondestructive Inspection During Additive Manufacturing of Metallic Parts

The research objective of this proposal is to demonstrate feasibility to collect and interpret in situ 3-D surface data for the laser sintered top surface for each layer in a powder bed process. The 3-D data collection will be performed with no interference with the operational efficiency and build time for the powder bed process. The 3-D data will be utilized to compute the distributions of surface roughness and top layer thickness. Physics-based models will be utilized to compute the nominal values for layer thickness, rewetting depth and build distortion. The measured 3-D data will be interpreted in real time in order to flag the potential regions for build anomalies that include build porosity, lack of fusion and build distortion. Statistical hypothesis testing will be utilized in order to assess the probability of false alarm. Deposition trials will be designed for alloy Ti-6Al-4V with the goal to collect and process the 3-D surface data and to verify the flagged locations for build anomalies using CT scan data.