A close look at temperature profiles during laser powder bed fusion using operando X-ray diffraction and finite element simulations

Model independent pre-processing of X-ray powder diffraction profiles

Precise knowledge of X-ray diffraction profile shape is crucial in the investigation of the properties of matter in crystals powder. Line-broadening analysis is a preprocessing step in most of the full powder pattern fitting softwares. Final result of line-broadening analysis strongly depends on preliminary three steps: Noise filtering, removal of background signal and peak fitting. In this wor...

Calculated Powder X-ray Diffraction Line Profiles via Absorption

We have calculated powder X-ray diffraction (PXRD) line profiles based on the absorption of X-rays in passing through materials. The results showed that the line profile function depends on the absorption coefficient of the sample. The observed aluminum PXRD patterns are in excellent agreement with the calculated line profile functions derived from absorption. This work also demonstrated that b...

X-Ray Powder Diffraction Metrics

To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true differe...

High-Temperature X-Ray Powder Diffraction of Secondary Gypsum

Using Design of Experiments in Finite Element Modeling to Identify Critical Variables for Laser Powder Bed Fusion

Input of accurate material and simulation parameters is critical for accurate predictions in Laser Powder Bed Fusion (L-PBF) Finite Element Analysis (FEA). It is challenging and resource consuming to run experiments that measure and control all possible material properties and process parameters. In this research, we developed a 3-dimensional thermal L-PBF FEA model for a single track laser sca...