A preliminary study on gas metal arc welding-based additive manufacturing of metal parts

A gas metal arc welding robot was used to build a thin-walled component made of mild steel on a low-carbon substrate according to the AM principle. Thereafter, the specimens for observing microstructures and mechanical properties were extracted from the built thin-walled component. The microstructures of the specimen were observed by an optical microscope; the hardness was measured by a digital microhardness tester, and the tensile tests were carried out on a tensile test machine.
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A preliminary study on gas metal arc welding-based additive manufacturing of metal partsScience & Technology Development Journal, 23(1):422-429 Open Access Full Text Article Research ArticleA preliminary study on gas metal arc welding-based additivemanufacturing of metal partsVan Thao Le* ABSTRACT Introduction: In the past three decades, additive manufacturing (AM), also known as 3D print- ing, has emerged as a promising technology, which allows the manufacture of complex parts byUse your smartphone to scan this adding material layer upon layer. In comparison, with other metal-based AM technologies, gasQR code and download this article metal arc welding-based additive manufacturing (GMAW-based AM) presents a high deposition rate and has the potential for producing medium and large metal components. To validate the technological performance of such a manufacturing process, the internal quality of manufactured parts needs to be analyzed, particularly in the cases of manufacturing the parts working in a crit- ical load-bearing condition. Therefore, this paper aims at investigating the internal quality (i.e., microstructures and mechanical properties) of components manufactured by the GMAW-based AM technology. Method: A gas metal arc welding robot was used to build a thin-walled com- ponent made of mild steel on a low-carbon substrate according to the AM principle. Thereafter, the specimens for observing microstructures and mechanical properties were extracted from the built thin-walled component. The microstructures of the specimen were observed by an optical microscope; the hardness was measured by a digital microhardness tester, and the tensile tests were carried out on a tensile test machine. Results: The results show that the GMAW-based AM- built thin-walled components possess an adequate microstructure that varies from the top to the bottom of the built component: lamellar structures with primary austenite dendrites in the upper zone; granular structure of ferrites with small regions of pearlites at grain boundaries in the middle zone, and equiaxed grains of ferrites in the lower zone. The hardness (ranged between 164±3.46 HV to 192±3.81 HV), yield strength (YS o f f set o f 0.2% ranged from 340±2 MPa to 349.67±1.53 MPa), and ultimate tensile strength (UTS ranged from 429±1 MPa to 477±2 MPa) of the GMAW-based AM-built components were comparable to those of wrought mild steel. Conclusions: The resultsAdvanced Technology Centre, Le Quy obtained in this study demonstrate that the GMAW-based AM-built components possess adequateDon Technical University, 236 Hoang microstructure and good mechanical properties for real applications. This allows us to confirmQuoc Viet, Bac Tu Liem, Hanoi, the feasibility of using a conventional gas metal arc welding robot for additive manufacturing orVietnam repairing/re-manufacturing of metal components. Key words: Additive manufacturing, Gas metal arc-based additive manufacturing, Mild steel,Correspondence Microstructures, Mechanical propertiesVan Thao Le, Advanced TechnologyCentre, Le Quy Don Technical University,236 Hoang Quoc Viet, Bac Tu Liem,Hanoi, Vietnam INTRODUCTION cording to the heat source used in AM, metal-basedEmail: thaomta@gmail.com In the past three decades, Additive manufacturing AM technologies can be classified into laser-based,History (AM), also known as 3D printing, has emerged as electron beam-based, and arc welding-based addi-• Received: 2019-10-03 a promising solution for manufacturing complex ge- tive manufacturing 4 . In comparison with laser-based• Accepted: 2019-11-26• Published: 2019-02-16 ometries and parts made of materials that are expen- and electron beam-based AM systems, welding-based sive and/or difficult to machine, for example, titanium additive manufacturing - also called wire arc ad-DOI : 10.32508/stdj.v23i1.1714 and nickel alloy 1 . In contrast to machining processes, ditive manufacturing (WAAM) has demonstrated AM technology builds a solid part by adding materials as a prospective solution for the manufacture of layer-by-layer from a substrate without using any ad- medium and large-dimensional metal parts 6 . More- ditional reso ...