Metal Cored Wire on Mechanical Properties and Microstructural Characteristics of Wire Arc Direct Energy Deposited Component

Objectives: Fabrication of a cylinder-shaped High-Strength Low Alloyed steel wall component through wire (metal cored) arc additive manufacturing and assess the homogeneity and integrity of the built component. Method: Mechanical testing and microstructural characterizations such as optical microscopy, scanning electron microscopy and electron backscattered diffraction techniques were performed at distinct regions (namely, bottom and top). Findings: The conducted tensile test at the bottom area recorded a tensile strength of 864 MPa, which is 5.9 % higher than the top region but with a lower total elongation. The microhardness study revealed that the average hardness at the bottom region was 266 HV0.5, while the top region was 241 HV0.5. The microstructural analysis conducted in both areas indicates that the bottom region exhibits better hardness and strength due to the presence of a high value of geometrically necessary dislocations, High-Angle Grain Boundaries and increased grains with reduced size. However, the built component proves to have better homogeneity with marginal deviations in the properties estimated. Novelty: Solid wire was used as a predominant filler material for the Wire-Arc Additive Manufacturing (WAAM) process, which requires high heat input to melt the material. Hence, to reduce the heat input, metal-cored wire was used instead of solid wire for the Gas Metal Arc -WAAM process. Keywords: Gas metal arc welding, Metal cored wire, Mechanical properties, Direct energy deposition, Wire-arc additive manufacturing