Experimental and numerical studies for evaluation of surface integrity in post-processing of additively manufactured nickel-based alloy by machining process

As a new technology, Additive Manufacturing (AM) provides an excellent opportunity to produce parts with complex geometry that would not be possible with traditional manufacturing methods. Against several advantages of AM technology, surface quality of an AM-built part might not be suitable for many applications. To solve this issue, one must use post-processing by machining process to obtain a suitable surface quality and dimensional accuracy of parts produced by AM. Regarding the machining processes, the desirable surface integrity of the machined components is one of the dominant requirements of the industries because it significantly affects the performance and service life of the final products. Inconel 718 alloy, as a difficult-to-cut material, has excellent properties. Not only few experimental studies are found in literature on machining of AM Inconel 718 alloy, but also, they have mostly limited to Conventional Machining (CM) processes. In addition, very few studies are found in literature on machining simulation of this new material due to absence of reliable material model for modeling the chip formation. To address this gap and aiming to push the fundamental science behind this problem, the main goal of the present project is to comprehensively evaluate the surface integrity condition after machining of AM Inconel 718. Firstly, the correlation between main AM parameters and machining characteristics are investigated. Then, a comparative experimental study will be conducted on CM, Cryogenic Cooling Machining (CCM) and Laser-Assisted Machining (LAM) to obtain desirable surface integrity after machining of AM Inconel 718 alloy. After that, fundamental advances for machining simulation of AM Inconel 718 will be presented. Based on this, identification of the new and reliable material model for machining simulation, innovative methods for predicting the surface integrity including microstructure changes and residual stress will be addressed at this project.