Optimization of Process Parameters to Improve the Effective Area of Deposition in GMAW-Based Additive Manufacturing and its Mechanical and Microstructural Analysis

Abstract

Additive manufacturing of metals using gas metal arc welding has an associated problem of variations of height in the onset and extinguishing parts of the weld bead. In this research, robot-assisted welding has been performed to investigate the problem, using AWS ER70S-6 low alloy steel welding electrode wire. After adjustment of welding parameters for a single-layer, single-pass, an optimal profile of welding energy was used to construct a thin wall which exhibited good forming characteristics with an effective area of approximately 97%. The resulting structure was ductile in nature with better tensile strength and microhardness as compared to the rolled steel available in industry with similar carbon content. The microstructure analysis revealed equiaxed grains in most parts of the structure having a fine grain size.

Analysis of Ductile Fracture Obtained by Charpy Impact Test of a Steel Structure Created by Robot-Assisted GMAW-Based Additive Manufacturing

“…As the fracture was purely in the upper shelf region and was ductile in nature, fracture toughness can be estimated using the relation [36,37]: K IC = 0.804 σ ys (CVN/σ ys − 0.0098) 0.5 (1) where K IC is the fracture toughness in MPa•m 1/2 , σ ys is the yield strength in MPa, and CVN is the Charpy impact absorbed energy in J. Using the average yield strength (330 MPa) of the structure from [16], the fracture toughness was found to be approximately 199 MPa•m 1/2 and 206 MPa•m 1/2 for the horizontal and vertical specimens, respectively.…”

“…This part of the deposition offers equilibrium in terms of height of the deposition and heat dissipation. The details of the same can be found in published literature mentioned in [16]. Deposition parameters for the steady stage part of the layer after equilibrium are provided in Table 2.…”

“…The height difference at the extreme ends is significant for multi-layer single-pass manufacturing, where the height difference is exaggerated with each layer being deposited, terminating the welding process [15]. Different techniques have been used to control the welding parameters and attain a maximum effective area in the resulting structure [13,16]. The resulting structure has different mechanical and material properties owing to the heat cycles of multiple layer depositions [17].…”

Optimization and Influence of GMAW Parameters for Weld Geometrical and Mechanical Properties Using the Taguchi Method and Variance Analysis

“…Yao, Zhou, Lin, Xu and Yue [14], through the double-pulsed GMAW technique, employed the grey relational based process to explore the weld bead forming rule and check the weld parameters effects, so a new method for the weld bead forming was set. Waqas, Qin, Xiong, Wang and Zheng [15] made an optimization of the effective area of deposition based on the GMAW additive manufacturing process parameters and the mechanical and microstructural of a multi-layer weld were analyzed.…”

A study on wire and arc additive manufacturing of low-carbon steel components: process stability, microstructural and mechanical properties

“…Recently, the GMAW-based AM process has been extensively investigated in terms of technological performance, optimization of process parameters, and metallurgical properties [11][12][13][14][15][16][17][18][19]. For example, Xiong et al [15] studied the possibility of using the GMAW-based AM process for fabricating inclined thin-walled components.…”