Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process

Abstract

In this research, four different welding arc modes including conventional cold metal transfer (CMT), CMT-Pulse (CMT-P), CMT-Advanced (CMT-ADV), and CMT pulse advanced (CMT-PADV) were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al2Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode.

Effects of Thermal Cycling on Wire and Arc Additive Manufacturing of Al-5356 Components

“…Melting of the filler material is achieved using electric arc or plasma as a heat source, thus combining well known arc welding processes such as gas metal arc welding (GMAW), gas tungsten arc welding (GTAW) or plasma arc welding (PAW) with wire as the feedstock [11][12][13]. Due to a simultaneously energy input and wire feed, the wire-feed orientation during GMAW is perpendicular to the forming substrate, offering advantages in automation and productivity [14].…”

Wire and Arc Additive Manufacturing of Aluminum Components

“…In contrast to GMAW (simultaneous energy input and material feed through consumable wire electrode), wire-feed orientations during GTAW and PAW can affect structure accuracy [11]. Accordingly, GMAW offers advantages in productivity and degree of automation [12]. Based on a low-heat input and precise energy distribution, the cold metal transfer (CMT) process by Fronius currently is the most common GMAW process used for additive manufacturing.…”

“…Because of the layer-by-layer built up approach, the WAAM process as well as the resulting structure are directly related to the welding parameters and material characteristics during welding [12]. Accordingly, an increasing number of studies on material processability, tool-path planning, and component properties can be found.…”

Effect of Heat Input on Formability, Microstructure, and Properties of Al–7Si–0.6Mg Alloys Deposited by CMT-WAAM Process

“…Compared with the high-energy beam and powder additive manufacturing [2,3], WAAM has a high forming efficiency, a high density of stacking body; compared with traditional forming methods (casting or forging) [4,5], WAAM has the characteristics of Buy-to-Fly ratio, excellent mechanical properties and short processing cycle. The cold metal transfer (CMT) technology has a high cladding efficiency, a low heat input, and no spatter [6,7]. Its application in the…”