Wire Arc Additive Manufacturing (WAAM) is an advanced manufacturing technique, especially known for its ability to produce large and complex-sized components with a high deposition rate.

With the advancement in WAAM, in-situ micro powder alloying during a deposition in order to modify each layer is of significant interest. This research highlights the increase in particulate matter emissions, emphasizing ultrafine particles (< 100 nm) from the micro-powder burning. Elevated temperature can also be the key factor for the increase in particulate matter emissions.

Two single bead multi-layered wall of medium carbon steel (ER70S6) were deposited in two conditions, namely as-deposited steel wall and interlayer micro powder added deposited steel wall. Hence, this work focuses on studying the metallurgical as well as mechanical characteristics of the steel produced through powder-added wire arc additive manufacturing using various techniques such as optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and Vickers microhardness testing.

It was observed that the microhardness of the manufactured steel increased due to the formation of specific microstructures such as ferritic-bainite and retained austenite as well as due to precipitation strengthening.

During deposition, the emissions arising from in-situ micro powder (titanium) alloyed deposition were also measured. Scanning mobility particle sizer (SMPS) was used to measure the size distribution of the sub-micron particles emitted from the processes. The findings suggest that the use of Ti powder for WAAM leads to a rise in emissions of ultrafine and fine particulate matter.

This article is shared by Adarsh Prakash, Rubal Dhiman, Anirudha Ambekar, Thaseem Thajudeen and Sachin D. Kore