Assessing the Effect of Infill Strategies on Hardness Properties of Cuboidal Parts Printed with Wire and Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) has gained prominence in its utilization in the manufacturing industry due to its ability to build large functional components at high deposition rates. Among the different metal additive manufacturing processes, WAAM has the potential for adoption in the industry due to the ease with which the system can be integrated into factory’s robotic welding cells. The ability to develop 3D components using welding has opened possibilities for redesigning and envisioning new product designs. However, there are still challenges related to ensuring process quality with WAAM. Path planning strategies have tremendous effects on structural integrity, mechanical and microstructural properties of the components. The current research aims to experimentally investigate the effect of different infill strategies on the hardness of cuboidal parts in WAAM. The experimental work uses high-strength low-alloy steel as the material of choice. These steels are found in many high-stress applications, such as automotive, load-bearing structures, and low-temperature applications that require a high strength-to-weight ratio. The study reported herein comprises of testing three different infill patterns and their impact on the final part performance (geometric, microscopic defects, and Vickers’ hardness). It was observed that all three strategies ensured a stable deposition process, yet with micro and macro defects. Lack of fusion defects and pores were identified in one of the infill strategies through microscopic evaluation. The hardness mapping showed uniform properties in separate planes for all printing strategies.