Predictive modeling of solidification during laser additive manufacturing of nickel superalloys: Recent developments, future directions

TL;DR

This paper reviews recent advances in predictive modeling of solidification during laser additive manufacturing of nickel superalloys, highlighting the importance of multiscale simulation for understanding microstructure evolution and material properties.

Contribution

It summarizes recent developments and future directions in multiscale modeling of solidification processes in laser AM of nickel superalloys.

Findings

Multiscale modeling enhances understanding of microstructure formation.

Solidification controls grain size, shape, and segregation.

Modeling aids in optimizing AM process parameters.

Abstract

Additive manufacturing (AM) processes produce parts with improved physical, chemical, and mechanical properties compared to conventional manufacturing processes. In AM processes, intricate part geometries are produced from multicomponent alloy powder, in a layer-by-layer fashion with multipass laser melting, solidification, and solid-state phase transformations, in a shorter manufacturing time, with minimal surface finishing, and at a reasonable cost. However, there is an increasing need for post-processing of the manufactured parts via, for example, stress relieving heat treatment and hot isostatic pressing to achieve homogeneous microstructure and properties at all times. Solidification in an AM process controls the size, shape, and distribution of the grains, the growth morphology, the elemental segregation and precipitation, the subsequent solid-state phase changes, and ultimately the material properties. The critical issues in this process are linked with multiphysics (such as fluid flow and diffusion of heat and mass) and multiscale (lengths, times and temperature ranges) challenges that arise due to localized rapid heating and cooling during AM processing. The alloy chemistry-process-microstructure-property-performance correlation in this process will be increasingly better understood through multiscale modeling and simulation.