The melt pool size and associated effects on bead geometry in WAAM

Abstract

Additive manufacturing (AM) is defined as “a process of joining materials, usually layer upon layer, to make objects from 3D model data.” According to ASTM- “AM is the opposite of subtractive methodologies.” [1]. It is a rapidly growing technology that is showing great potential at lowering the production costs by reduction of material wastage and reduction of the time to manufacture. Additionally, it gives more freehand to the designers. [2]. Metal AM has a commonplace in various sectors i.e., aerospace industries, automotive industries, energy generation industries, and medical industries. It is expected that these industries will capture more than 80% of the additive manufacturing market by 2025 [3]. Additive manufacturing (WAAM) is one of the various variants of the DED technique, which is a modified process of welding processes such as gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), plasma arc welding (PAW) [4]. WAAM has more to promise than previous AM technologies since it advances due to a better effective metal deposition rate, lower energy consumption, improved energy efficiency, a wider range of accessible materials, and lower equipment costs due to no abrasion of machine and tool parts. [5]. In our studies, we have focused on implementing an innovative and efficient WAAM deposition method to fabricate stainless steel specimens using 2 wires to feed simultaneously (double-wire feed) [6] for deposition and Wire arc additive manufacturing process (DWF-WAAM) and try to make bead parameters more uniform by controlling the deposition parameter. Various characteristics exhibited by the DWF WAAM process will be studied and analysed i.e., the melt pool parameters and bead appearance along with bead parameter of the test components will be investigated. It was expected that the DWF-WAAM method can be applied for high efficiency and high deposition rate applications because the temperature and power distribution of arc between electrode and melt pool is bell shaped and the wire that is fed covers a very less area of arc zone. So, a substantial amount of energy goes to the melt pool which can be utilized for second wire deposition [6]. Along with it, we have tried to make the bead parameters more uniform using some modifications in the deposition parameters.