Finish Machining of Additive Manufactured Metals

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Additive manufacturing (AM) creates geometries by depositing/spreading material layer-by-layer wherever desired and was historically used as a convenient method to make prototypes for demonstration or pre-use assessment. Significant progress in technology and equipment has resulted in an awareness of the capabilities of AM for producing highly customized parts for service applications. Hence, there has recently been a surge in the number of research projects exploring the capabilities and potential applications of AM. This trend also encouraged the manufacturing industry to explore metals, rather than easy to deposit materials such as plastics. However, one of the major roadblocks toward the wide application of AM metallic parts goes back to their inherent layer-by-layer nature where each layer is deposited and solidified over the previous layer. Other issues with AM parts are poor surface quality and lack of dimensional accuracy, which are critical factors for many applications. Therefore, post processing the AM parts is an inevitable step toward preparing them for their service life. Post processing AM parts to attain the desired tolerances is mainly achieved using finish machining. Successful machining highly depends on the characteristics of material to be machined. Machining also alters the surface and subsurface characteristics, which needs thorough investigation. The proposed NSERC DG program specifically focuses on three interconnected areas: Studying the effect of AM on the mechanical behavior of AM metals Developing a constitutive equation and a force model for machining AM metals to predict the cutting forces based on the mechanical properties of AM metals Investigating the attainable surface integrity after finish machining of AM metals Process of choice will be metal powder bed fusion (laser beam), as a widely used AM technique. Materials of focus will be titanium alloys and superalloys (nickel-based) that are widely used in aerospace industry and are more likely candidates for AM, due to their difficult-to-cut nature. The proposed research will enable the manufacturing industry to have a better understanding of the expected material behavior during the post-process finish machining of metallic parts after AM. It will also enable training of students in key areas pertaining to both machining and additive manufacturing. The exclusive targets of this research make the proposed program particularly unique and specialized due to the fact that, to the best of my knowledge, there has not yet been extensive research pertaining to the post-process finish machining of AM metallic parts. This research will certainly lead to future progress, particularly, concerning the quality, integrity, and overall performance of the AM metals that undergo post-process finish machining. The manufacturing sector serves as one of the main driving forces for Canada's economy; hence, the proposed research holds great promise for the Canadian economy.