Prediction of Primary Dendrite Arm Spacing in Pulsed Laser Surface Melted Single Crystal Superalloy

Abstract

Primary dendritic arm spacing (PDAS) is an important microstructure feature of the nickel-base single crystal superalloys. In this paper, a numerical model predicting the PDAS evolution with additive manufacturing parameters using pulsed laser is established, which combines the theoretical PDAS models with the temperature field calculation model during pulsed laser process. Based on this model, processing maps that related process parameters to the evolution of PDAS are generated. To obtain more accurate prediction model, the parameters of different solidification conditions, $\overline{{G^{ - 0.5} V^{ - 0.25} }}$ and $\overline{{G}^{-0.5}{V}^{-0.25}}$, are selected to calculate PDAS. The simulation results show that the PDAS increases as the arise of P and t. The processing-PDAS map can accurately predict the evolution of PDAS with pulsed laser process parameters, which is well in accordance with the experimental results. Additionally, the PDAS values calculated by the $\overline{{G}^{-0.5}{V}^{-0.25}}$ are more in line with the experimental results than those calculated by the ${\bar{G}}^{-0.5}{\bar{V}}^{-0.25}$.