scholarly journals Comparison of the mechanical properties of Grade 5 and Grade 23 Ti6Al4V for wire-arc additive manufacturing

Author(s):  
L. Mashigo ◽  
H. Möller ◽  
C. Gassmann

SYNOPSIS Wire-arc additive manufacturing (WAAM) is a directed-energy deposition technology that uses arc welding procedures to produce computer-aided designed parts, such as three-dimensional printed metal components. A challenge of additive manufacturing is the anisotropy. Interstitial elements play a significant role in the mechanical properties of Ti6Al4V of different grades. In this research, the mechanical properties of Grade 5 and Grade 23 Ti6Al4V were compared for this application. Samples were extracted from WAAM-produced Ti6Al4V walls in different directions (horizontal and vertical) and at different positions (top and bottom). The samples were subjected to optical microscopy and tensile and hardness tests. Grade 5 Ti6Al4V samples were found to have greater strength, greater hardness, and lower ductility, owing to the higher content of interstitial elements compared with Grade 23. The bottom samples had higher strength than the top samples, which is attributed to thermal cycling during manufacturing, resulting in different microstructures. Keywords: Ti6Al4V, wire-arc additive manufacturing, anisotropy, heat accumulation, interstitial elements.

Author(s):  
Vivek Kumar P ◽  
◽  
Soundrapandian E ◽  
Jenin Joseph A ◽  
Kanagarajan E ◽  
...  

Additive manufacturing process is a method of layer by layer joining of materials to create components from three-dimensional (3D) model data. After their introduction in the automotive sector a decade ago, it has seen a significant rise in research and growth. The Additive manufacturing is classified into different types based upon the energy source use in the fabrication process. In our project, we used self-build CNC machine that runs MACH3 software, as well as the MACH3 controller is used to control the welding torch motion for material addition through three axis movement (X, Y and Z). In the project we used ER70 S-6 weld wire for the fabrication and examined its microstructure and mechanical properties. Different layers of the specimen had different microstructures, according to microstructural studies of the product. Rockwell hardness tester used for testing hardness of the product. According to the observation of the part fabricated components using the Wire Arc Additive Manufacturing process outperformed the mechanical properties of mild steel casting process. The product fabricated by Wire Arc Additive Manufacturing process properties is superior to conventional casting process.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1004 ◽  
Author(s):  
Baoxing Wang ◽  
Guang Yang ◽  
Siyu Zhou ◽  
Can Cui ◽  
Lanyun Qin

A novel on-line vortex cooling powered by low-cost compressed air was proposed to reduce common defects such as low forming precision, coarse grains, and pores caused by heat accumulation in the Wire Arc Additive Manufacturing (WAAM) of aluminum alloy. The impacts of interlayer cooling (IC), substrate cooling (SC), on-line cooling (OL), and natural cooling (NC) processes were compared on the morphology, microstructure, and mechanical properties of as-deposited walls, revealing that the OL process significantly lowers the interlayer temperature and improves forming precision. The high cooling rate produced by the OL process reduced the absorption of hydrogen in the molten pool, lowering porosity. Furthermore, the grains are refined due to the developed undercooling. However, the high cooling rate enhanced the segregation potential of Mg element and raised the content of the β phase. Conclusively, the maximum tensile strength, elongation, and microhardness of the as-deposited wall are achieved via the OL process, and the fine-grain strengthening mechanism plays an important role in improving mechanical properties. The OL process is cheaper and poses a significant effect; it is highly suitable for the additive manufacturing of complex components compared with other forced cooling processes.


Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Chengxun Zhang ◽  
Zhijun Qiu ◽  
Hanliang Zhu ◽  
Zhiyang Wang ◽  
Ondrej Muránsky ◽  
...  

Relatively high heat input and heat accumulation are treated as critical challenges to affect the qualities and performances of components fabricated by wire arc additive manufacturing (WAAM). In this study, various heat inputs, namely 276, 552 and 828 J/mm, were performed to fabricate three thin-wall Inconel 625 structures by cold metal transfer (CMT)-based WAAM, respectively, and active interpass cooling was conducted to limit heat accumulation. The macrostructure, microstructure and mechanical properties of the produced components by CMT were investigated. It was found that the increased heat input can deteriorate surface roughness, and the size of dendrite arm spacing increases with increasing heat input, thus leading to the deterioration of mechanical properties. Lower heat input and application of active interpass cooling can be an effective method to refine microstructure and reduce anisotropy. This study enhances the understanding of interpass temperature control and the effectiveness of heat inputs for Inconel 625 alloy by WAAM. It also provides a valuable in situ process for microstructure and mechanical properties’ refinement of WAAM-fabricated alloys and the control of heat accumulation for the fabrication of large-sized structures for future practical applications.


Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 513
Author(s):  
Jae Won Kim ◽  
Jae-Deuk Kim ◽  
Jooyoung Cheon ◽  
Changwook Ji

This study observed the effect of filler metal type on mechanical properties of NAB (NiAl-bronze) material fabricated using wire arc additive manufacturing (WAAM) technology. The selection of filler metal type is must consider the field condition, mechanical properties required by customers, and economics. This study analyzed the bead shape for representative two kind of filler metal types use to maintenance and fabricated a two-dimensional bulk NAB material. The cold metal transfer (CMT) mode of gas metal arc welding (GMAW) was used. For a comparison of mechanical properties, the study obtained three specimens per welding direction from the fabricated bulk NAB material. In the tensile test, the NAB material deposited using filler metal wire A showed higher tensile strength and lower elongation (approx. +71 MPa yield strength, +107.1 MPa ultimate tensile strength, −12.4% elongation) than that deposited with filler metal wire B. The reason is that, a mixture of tangled fine α platelets and dense lamellar eutectoid α + κIII structure with β´ phases was observed in the wall made with filler metal wire A. On the other hand, the wall made with filler metal wire B was dominated by coarse α phases and lamellar eutectoid α + κIII structure in between.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 939
Author(s):  
Mukti Chaturvedi ◽  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Luigi Renato Mistodie ◽  
Danut Mihailescu ◽  
...  

Wire arc additive manufacturing (WAAM) is a fusion manufacturing process in which the heat energy of an electric arc is employed for melting the electrodes and depositing material layers for wall formation or for simultaneously cladding two materials in order to form a composite structure. This directed energy deposition-arc (DED-arc) method is advantageous and efficient as it produces large parts with structural integrity due to the high deposition rates, reduced wastage of raw material, and low consumption of energy in comparison with the conventional joining processes and other additive manufacturing technologies. These features have resulted in a constant and continuous increase in interest in this modern manufacturing technique which demands further studies to promote new industrial applications. The high demand for WAAM in aerospace, automobile, nuclear, moulds, and dies industries demonstrates compatibility and reflects comprehensiveness. This paper presents a comprehensive review on the evolution, development, and state of the art of WAAM for non-ferrous materials. Key research observations and inferences from the literature reports regarding the WAAM applications, methods employed, process parameter control, optimization and process limitations, as well as mechanical and metallurgical behavior of materials have been analyzed and synthetically discussed in this paper. Information concerning constraints and enhancements of the wire arc additive manufacturing processes to be considered in terms of wider industrial applicability is also presented in the last part of this paper.


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