  Quality control in additive manufacturing can be achieved through variation
control of the quantity of interest (QoI). We choose in this work the
microstructural microsegregation to be our QoI. Microsegregation results from
the spatial redistribution of a solute element across the solid-liquid
interface that forms during solidification of an alloy melt pool during the
laser powder bed fusion process. Since the process as well as the alloy
parameters contribute to the statistical variation in microstructural features,
uncertainty analysis of the QoI is essential. High-throughput phase-field
simulations estimate the solid-liquid interfaces that grow for the melt pool
solidification conditions that were estimated from finite element simulations.
Microsegregation was determined from the simulated interfaces for different
process and alloy parameters. Correlation, regression, and surrogate model
analyses were used to quantify the contribution of different sources of
uncertainty to the QoI variability. We found negligible contributions of
thermal gradient and Gibbs-Thomson coefficient and considerable contributions
of solidification velocity, liquid diffusivity, and segregation coefficient on
the QoI. Cumulative distribution functions and probability density functions
were used to analyze the distribution of the QoI during solidification. Our
approach, for the first time, identifies the uncertainty sources and frequency
densities of the QoI in the solidification regime relevant to additive
manufacturing.
