Additive manufacturing (also called 3D printing) is now capable of producing/building complex-shaped metal components strong enough for structural applications. However, standard qualification methods for traditional manufacturing are not suitable for additive manufactured parts because the mechanical behavior of these parts is fundamentally different from those made by traditional means. Hence, the goal of this research is to develop a highly reliable, low-cost, and efficient qualification method for additive manufactured components based on a combined approach of validated computer simulations and non-destructive evaluation techniques. This qualification method will potentially lead to much wider adoption of additive manufacturing and will impact applications requiring complex, high value, time-sensitive, and customized products and prototypes such as automobile and aerospace parts (i.e., complex designs), broken part replacement (i.e. time-sensitive), and medical implants (i.e., highly customized). The skills and knowledge the students gain in this project will prepare them for active roles in securing the the United States' leadership in manufacturing engineering for future generations.
To achieve its goal, this project has the following objectives: 1) Characterize key microstructure features and mechanical properties across multiple length scales; 2) Develop a probabilistic constitutive model to capture sub-micron mechanical behavior; 3) Develop a macroscopic model based on microstructure data from various non-destructive evaluation techniques; and 4) Test the qualification method on a complex part. This research tackles a challenging problem in the reliable qualification of additive manufactured structural components whose local microstructure and mechanical behavior may vary widely among different builds of the same component. The utilization of X-ray micro computed tomography guarantees that any microscale flaws in the materials being scanned can be detected so that direct simulation of their mechanical behavior in the design component is possible. Through the multiscale investigation, a constitutive model will be developed to capture the mechanical effects of flaws, grain size, and residual stress. The integration of various nondestructive evaluation techniques with physics-based modeling will thus enable a rapid, reliable, and low-cost qualification method for additive manufactured components.
