Application of a manufacturing model for the optimization of additive processing of Inconel alloy 690

Abstract

Abstract Directed light fabrication (DLF) is an additive processing method that fuses metal powders, delivered by inert gas into the focal zone of a high powered laser beam, to form a fully dense metal deposit. Computer aided design and manufacturing (CAD/CAM) was used to simulate and specify the metal deposition process for the formation of a three dimensional part using Inconel alloy 690. This study demonstrates the ability to directly fabricate a complex, near net shaped object using a DLF machine with an alloy that is difficult and costly to fabricate using conventional processing methods. The fabrication of a monolithic hexagonal shape with through holes is described with the associated CAD/CAM additive processing case study, metallographic examination, and part characterization. The deposition of a fully dense nickel base alloy component was performed and achieved a high degree of dimensional accuracy. A comparison between the DLF deposited shape and the original part definition illustrates that near-net-shape tolerance levels are attainable within a 0.1 mm envelope. The single step production of fully dense, near net shaped, three dimensional metal parts directly from a computer based manufacturing model is compared with conventional processing methods currently available. As a result, significant process flexibility — beyond that of conventional processing capabilities is recognized — with potentially lower production costs, higher quality components, and the realization of higher performance designs.