On the effects of additive manufacturing process parameters on the performance of Hastelloy-X: A neutron diffraction experiment and crystal plasticity finite element model
Abstract
Additive manufacturing (AM) is increasingly becoming one of the favourable manufacturing techniques in various industries, such as transportation and energy. The reason for the extensive use of AM lies in the ability to use a wide range of process parameters for manufacturing engineering parts with complex geometries that cannot be effectively manufactured using traditional methods such as casting or forging. Understanding the role of process parameters is crucial for developing predictive models, as well as for manufacturing engineering components with the desired properties.
This research aims to characterize the influence of AM process parameters on the deformation mechanisms of Hastelloy-X, a nickel superalloy used in gas turbine engines. In-situ neutron diffraction, electron backscatter diffraction (EBSD) and crystal plasticity finite element (CPFE) analysis are used for this purpose. The Hastelloy-X samples were printed using laser power bed fusion (LPBF) AM technique. Here, attention is given to the effects of laser power and scanning speed. First, a literature review is provided in Chapter 2, which is followed by Chapter 3 that contains a detailed description of sample preparation, experimental set-up, and data processing. The results are presented and discussed in Chapter 4. Lastly, conclusions and future works are presented in Chapter 5.
The experimental results show that the microstructure, texture, and the degree of anisotropy of the printed samples significantly change with changing AM parameters. By comparing the evolution of lattice strains predicted from CPFE to those from experiments, it is shown that {111}is the active deformation mechanism in all printed samples.