Real Time Non-Destructive Evaluation during 3D Manufacturing of Metal Parts

Additive manufacturing, such as laser sintering or melting of additive layers can produce parts rapidly at small volume and in a factory setting.To make the parts nuclear quality, a real-time non-destructive evaluation (NDE) technique is required to detect defects while they are being manufactured.The proposed NDE technique is a feasibility study of an optical sensor unit that is incorporated in a direct laser sintering machine to capture defects in real-time.The sensor data can be used to identify defects as they occur such that immediate corrective action can be taken.It also provides parameters that enable the prediction if the part is of nuclear quality.The proposed work is a multi-parameter sensing approach, incorporating multiple optical sensing and imaging techniques.The apparatus will be incorporated in a 3D metal printing machine.The final outputs of the sensors will be combined to produce a defect map in real-time as the part is being printed.Defects such as voids improper melting, bulging of the metal, and out-of-spec prints will be revealed.During Phase I, the feasibility of using multi- parameter NDE approach has been successfully demonstrated using a combination of theory and experiments.Samples with representative defects that occur during additive manufacturing of metal parts were prepared and tested, demonstrating the ability and effectiveness of the proposed approach.During Phase II, a prototype NDE unit will be fabricated.Samples will be tested and defect data will be obtained.Defect parameters will be extracted from the data and compared to actual defect values, and accurate prediction of defect parameters will be demonstrated.When this NDE technology is commercialized, the sensor unit will be incorporated in 3D printing machines without requiring design changes to the machine.The unit will detect printing defects in real-time.The sensor data will be utilized to pre-qualify parts for nuclear quality, and therefore minimize or eliminate the need for post fabrication testing.The economic benefits include reduction of cost of post-process testing, and significant reduction of loss of labor and material due to faulty parts.DOE and other branches of the government will benefit by streamlining the nuclear parts manufacturing.The reduced cost of manufacturing will help transition to modern nuclear energy, which will benefit the public by providing safe and cost effective energy solution.Other applications include NDE for manufacturing parts for the aerospace industry.