Numerical analysis of fused-coating metal additive manufacturing

Abstract

Limited build volumes, slow deposition rates, high feedstock costs and high machine costs significantly limit the current metal additive manufacturing market to researchers and large industrial users. In this paper, a new metal additive manufacturing (AM) process, referred to as the ‘‘metal fused-coating additive manufacturing (MFCAM),’’ was developed for high-efficiency deposition of metal parts. The new process is the combination of the metal fused-coating process and laser surface-melting process. A numerical investigation of the transient transport phenomena occurring during the fused-coating process was performed. The prevailing physical mechanisms of the fused-coating process, including the bulk liquid metal, capillarity effects at the liquid-solid interface, heat transfer, the solidification morphology of the coated layers, are identified and quantified numerically. The numerical models are validated with recent experimental results. The comparison between the numerical simulations and the experimental findings shows a good agreement. The interdependency of substrate moving speed, the height of gap between fused-coating head and substrate, the melt flow rate, and solidification morphology of the coated layers is examined in order to describe the forming process. This understanding is essential to implement effective process control in metal fused-coating additive manufacturing.