Optimisation of process parameters for deposition of colmonoy using directed energy deposition process

Abstract

Directed energy deposition (DED) process is an additive manufacturing technology that involves feeding metal powder through a nozzle onto the substrate whilst simultaneously fusing it with a laser. This paper presents a study on process parameters optimization for achieving better hardness for deposition of Colmonoy 52 SA by DED process. Colmonoy 52 SA is a hard nickel-chromium-boron alloy containing chromium carbides which has better abrasion and corrosion resistance. It is fundamental to control the process parameters such as laser power, powder feed rate and laser scan speed to get the quality deposition. In this work, the process parameters were optimized to obtain microstructure without porosity and good interfacial bonding between the substrate and the deposition. Taguchi's L9 method was used for optimization experiments and the explored ranges of powder feed rate, laser power and laser scan speed were 3–5 g/min, 300–500 W and 400–800 mm/min respectively. The microstructure and microhardness of the built specimens were studied.