Correlation between microstructure and residual stress in the additively manufactured products using advanced experimental characterizations

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The concept of additive manufacturing (AM) in metallic materials such as steels, titanium alloys, and**biocompatible metals has gained enough attention to fabricate parts from easy to complex shape and geometry**more interestingly as semi-final or final products. The huge benefit from AM processes is to print the complete**shape of product in one step in contrary to conventional manufacturing processes where several steps are**required. The process has been developed over a few decades and it has become possible to produce 100%**dense bulk materials. In some industries such as marine industry and biomedical industry, certified products are**being fabricated. However, the mechanical properties may not meet the expectations in service due to complex**microstructure formed during AM processes. Due to repeated multiple thermal cycles induced by the**liquidation and solidification cycles applied to fabricate additive manufactured (AMed) products, different**level of recovery, local plastic deformation and structural discontinuities can be found in parts. As-fabricated**products own higher ultimate strength compared to their conventional versions but they show lower ductility**together with highly textured grains. This causes premature failure during mechanical evaluation. Therefore,**deep mechanical and metallurgical investigations are required to improve the part microstructures by**identifying the micro-mechanisms responsible for early failure and the solutions to improve mechanical**properties. The main objective of this project is described in the above explained context and aims to develop**an empirical model predicting the relationship between microstructural heterogeneities, residual strains**accumulated in the microstructure and resulted mechanical properties.