The primary purpose of this LDRD project was to characterize the laser deposition process and determine the feasibility of fabricating complex near-net shapes directly from a CAD solid model. Process characterization provided direction in developing a system to fabricate complex shapes directly from a CAD solid model. Our goal for this LDRD was to develop a system that is robust and provides a significant advancement to existing technologies (e.g., polymeric-based rapid prototyping, laser welding). Development of the process will allow design engineers to produce functional models of their designs directly from CAD files. The turnaround time for complex geometrical shaped parts will be hours instead of days and days instead of months. With reduced turnaround time, more time can be spent on the product-design phase to ensure that the best component design is achieved. Maturation of this technology will revolutionize the way the world produces structural components.

In direct laser metal deposition technologies, such as the Laser (LENS) process, it is important to understand and control the Engineered Net Shaping thermal behavior during fabrication. With this control, components can be reliably fabricated with desired structural material properties. This talk will describe the use of contact and imaging techniques to monitor the thermal signature during LENS processing. Recent results show a direct correlation between thermal history and material properties, where the residual stress magnitude decreases as the laser power, and therefore thermal signature, increases. Development of an understanding of solidification behavior, residual stress, and microstructural evolution with respect to thermal behavior will be discussed.