Effect of the Heat Input on Wire-Arc Additive Manufacturing of Invar 36 Alloy: Microstructure and Mechanical Properties

Abstract

Invar, also known as FeNi36, is a material of great interest due to its unique properties, which makes it an excellent alternative for sectors such as tooling in aeronautics and aerospace. Its manufacture by means of wire arc additive manufacturing (WAAM) technology could extend its use. This paper aims to evaluate the comparison of two of the most widespread WAAM technologies: plasma arc welding (PAW) and gas metal arc welding (GMAW). This comparison is based on the analysis of wall geometry, metallography, and mechanical properties of the material produced by both technologies. The results show a slight increase in toughness and elongation before fracture and worse tensile strength data in the case of PAW, with average values of 485 MPa for ultimate tensile strength (UTS), 31% for elongation and 475 MPa, 40% in GMAW and PAW, respectively. All results gathered from the analysis show the possibility of successful manufacturing of Invar by means of WAAM technologies. The novelties presented in this paper allow us to establish relationships between the thermal input of the process itself and the mechanical and metallographic properties of the material produced.

The Use of Virtual Sensors for Bead Size Measurements in Wire-Arc Directed Energy Deposition

“…Of the arc-DED techniques, gas metal arc welding (GMAW) stands out for its elevated deposition rates, surpassing other wire-based technologies, such as plasma-based arc-DED and gas tungsten arc welding (GTAW) [6,7]. The utilization of Invar, an alloy, within this realm adds an intriguing dimension, leveraging its distinctive mechanical properties [8,9]. Comprising predominantly iron (64%) and nickel (36%) alloys, Invar finds purpose across diverse fields [10,11].…”

“…Amid the importance of final bead geometry analysis, the challenge of online process control remains pronounced [25]. Infrared pyrometry techniques for melt-pool measurement have found favor within integrated process monitoring systems [26][27][28], some even hinting at symmetries in the generated geometries [9], thus offering a realm of exploration for the research community.…”

Effect of Nitrogen‐Added Shielding Gas on Microstructure Evolution of Welded Joints by Gas Tungsten Arc Welding Process in Duplex Stainless Steel 2205

“…In fact, the inherent thermal gradients in joining technologies can greatly affect the ferrite-austenite ratio, which influences the mechanical behavior and corrosion resistance of the resulting joint. [26][27][28][29][30][31] Various joining techniques, such as arc welding, high-energy processes, or solid-state welding, have been employed to meet the requirements imposed on these materials. However, avoiding the ferritization of the weld zone (WZ) and the heat-affected zone (HAZ), without compromising the mechanical and anticorrosive properties due to the formation of second phases and/or precipitates, is a challenge in the manufacturing of DSS.…”