Investigation of the Effect of Aluminium Addition on the Additively Manufactured SS309L Alloy

Additive manufacturing (AM) is a highly advanced manufacturing technology that involves metal layers deposition in order to increase the efficiency of component production and costs reduction. Current study includes examining the effects of adding aluminium as an additional alloying element to austenitic stainless -steel SS 309L. Metal Inert Gas (MIG) welding apparatus was used as a heat source for the deposition of the steel in the Wire Arc Additive manufacturing method. Simultaneously during the building process, three different percentages (0, 2.5%, and 5%) of an external aluminium alloy 4043 (E4043) cold wire was introduced into the fusion zone. The focus of the study is to highlight the influence of adding E4043 on the microstructure and mechanical properties of additively manufactured SS309L. For the microstructural investigations, optical microscopy and scanning electron microscopy (SEM) were used, whereas a Vickers microhardness test was used to investigate the effect of these additions on the local mechanical properties. On the other hand, the mechanical behavior of the deposited parts was examined using tensile test. The results of the study demonstrated that the addition of the aluminum alloy is significantly affect the mechanical properties of the deposited portions. The quantity of the added aluminum is discovered to have an influence on the microstructure, hardness, and tensile strength. Moreover, the homogenizing thermal treatment improved the samples' microstructure and overall properties. The found results highlights the importance of considering double wire feeding in additive manufacturing processes to reach the desired microstructural and mechanical properties in the final products.