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

增材制造（AM）在金属材料（如钢，钛合金和 ** 生物相容性金属）中的概念已经得到了足够的关注，可以制造从简单到复杂形状和几何形状的零件 ** 更有趣的是作为半成品或最终产品。AM工艺的巨大好处是在一个步骤中打印出产品的完整形状，而传统的制造工艺需要几个步骤。该工艺已经发展了几十年，已经可以生产100%** 致密的散装材料。在某些行业，如海洋工业和生物医学工业，认证产品正在制造。然而，由于AM工艺过程中形成的复杂 ** 微观结构，机械性能可能无法满足使用要求。由于应用于制造增材制造（AM ed）产品的液化和固化循环引起的重复的多个热循环，可以在部件中发现不同的恢复水平、局部塑性变形和结构不连续性。与传统产品相比，预制产品具有更高的极限强度，但它们显示出更低的延展性 ** 以及高度织构化的晶粒。这会导致机械评估期间过早失效。因此，需要进行深入的机械和冶金研究，以通过确定导致早期失效的微观机制和改善机械性能的解决方案来改善零件的微观结构。该项目的主要目标在上述背景下进行了描述，旨在开发 ** 一种经验模型，预测微观结构不均匀性、微观结构中积累的残余应变 ** 和由此产生的机械性能之间的关系。

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.