Online geometry quality assessment during directed energy deposition metal additive manufacturing using laser line scanner

Abstract

(3) there is a lack of real-time geometry monitoring and geometry estimation for depositions with sharp features, such as corners and intersections. Therefore, this research provides approaches to achieve online geometry quality assessment during the DED process using laser line scanner, including real-time geometry monitoring and real-time geometry estimation. In addition, this research put emphasis on geometry with sharp features which are often problematic and not well studied in previous literatures. The proposed online geometry assessment techniques could effectively facilitate DED to achieve zero-defect manufacturing and assist its adoption in various fields including the construction industry.

(2) real-time geometry estimation that can establish explicit relationship between process parameters and geometry attributes is not well studied, which impedes the development of geometry quality control

Metallic materials are widely adopted in the construction industry. While traditional manufacturing techniques such as hot-rolling, cold-forming and extrusion often leads to prismatic structural components, adopting metal additive manufacturing (AM) technologies, such as Directed Energy Deposition (DED), will allow greater flexibility in the geometry of construction components. However, geometry inconsistency in DED is one of the main problems that hinders its application in construction industry. Lack of timely geometry assessment during DED process results in dimensional errors and defects of final products. Therefore, this research proposes to develop and integrate advanced process monitoring techniques into a DED system with a goal of online geometry quality assessment in support of quality assurance and process certification. To achieve geometry quality control, geometry quality assessment including geometry monitoring and geometry estimation are needed. According to existing literature review about geometry quality assessment during DED process, the research gaps are identified: (1) there is a lack of online real-time geometry monitoring technique to inspect each deposited track profile, which requires the integration of 3D geometry monitoring system with DED system