VARIATION OF OPTIMAL GAS-SUPPLY CONDITION ALONG WITH DEPOSITION HEIGHT IN DIRECTED ENERGY DEPOSITION

Directed energy deposition (DED), which is one of additive manufacturing applicable to metals, laminates the material on a baseplate by melting and solidifying with a high-power heat source. In terms of powder-based DED, the material waste tends to be large because powder flow is difficult to converge on the melt pool precisely. This study evaluates the variation in powder distribution when the deposition height is changed in order to obtain the optimal gas-flow rate and powder-nozzle shape. The powder flow is estimated with a computational fluid dynamics simulation based on Euler-Lagrange approach. The simulation results indicate that the proposed nozzles can achieve the high powder convergence stably even if the total amount of gas supply is reduced.