The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is in influencing the whole metal manufacturing and materials processing industries by providing the capability of "Certify as You Build". The in-situ measurement/prediction of composition, phase transformation and manufacturing defect using the proposed spectroscopic sensor may also allow for the fabrication of near net shape and property (NNSP) components with heterogeneous structures and complex geometries for additive manufacturing industry. The project's vision is to achieve "zero-scrap" materials processing and metal manufacturing operations, enabling dramatically reduced post-processing to identify composition, microstructure and manufacturing qualities. The project would provide sensing and process control to reduce waste and save time during welding and additive manufacturing processes. These savings would directly convert to dollars for the manufacturer, so there is strong motivation for adoption. Thus the proposed smart optical monitoring sensor will significantly contribute to the much needed transformation of the U.S. manufacturing industries.<br/><br/><br/>The key innovation is to use optical emission spectroscopy of plasma to dramatically improve welding and additive manufacturing processes. The innovation actually goes far beyond sensing to categorize defects and predict composition and phase transformations. Its success relies heavily on signal processing and understanding the physical mechanisms of the manufacturing processes being monitored. The sensor and associated algorithms will lead to much more efficient manufacturing because of improved feedback control afforded by the process information provided. The key challenges lie in demonstrating on the shop floor 1) in-situ monitoring and control of phase transformation and composition by systematic diagnosis of the laser induced plasma, and 2) ability to detect and categorize manufacturing defects through understanding the effects of different defects on plasma and designing effective algorithms to interpret plasma signals. Phase II activities are directed towards meeting those challenges and establish the sensor?s reliability for its earliest possible commercialization. The project will contribute to the competitive advantage for American metal manufacturing industry with "Certify as You Build" capability with its spectroscopic sensor called, minimize material wastage and lost labor time, and increase long-term product quality.