Investigating the Surface and the Defect Structures of Laser Powder Bed Fusion Haynes 282 with Complex Geometry

With the invention of laser powder bed fusion additive manufacturing, the manufacturing industry has been revolutionized. Novel structures that were impossible to make in the past are now fabricable, allowing for creative design. Numerous research has been conducted to improve the microstructure, properties, and performance of additively manufactured metals, such as Haynes 282, to serve in high temperature applications. However, limited information is available for fabricating Haynes 282 with complex geometries with low defect content. The missing information is in how to fabricate Haynes 282 in different machines, with different sizes, with a better surface finish. Here, we discuss methods to predict the process parameters that produce Haynes 282 in a new machine with minimum porosity, followed by methods to predict the shift in the optimal process parameters when printing thin walls. In addition, methods to predict and optimize surface roughness and build time will be discussed. This thesis hopes to provide insights into the effect of laser rastering and thermal flow during the process on the development of the process window for the alloy in various sizes with enhanced surface precision and productivity, so that the additive manufacturing method can be used to fabricate part-scale components such as heat exchangers.