Microstructure and Mechanical Properties of Pulse MIG Welded 6061/A356 Aluminum Alloy Dissimilar Butt Joints

Nie, Fuheng; Dong, Honggang; Chen, Su; Li, Peng; Leyou, Wang; Zhou-xing, Zhao; Li, Xintao; Zhang, Hai

doi:10.1016/j.jmst.2016.11.004

Cited by 77 publications

(23 citation statements)

References 25 publications

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“…This is a typical fracture feature of a ductile material formed during the microvoid coalescence. However, since there were some gas pores formed during the LFP process, the fracture surface of the LFP part contains quasi-cleavages, slip regimes, sparse dimples, and elongated gas pores, as shown in Figure 8b [33,34]. Thus, the parts fabricated by the LFP process have less ductility.…”

Section: Resultsmentioning

confidence: 99%

Aluminum Parts Fabricated by Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, and Mechanical Properties

Hung

Sutton

et al. 2020

Materials

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Fabrication of dense aluminum (Al-1100) parts (>99.3% of relative density) by our recently developed laser-foil-printing (LFP) additive manufacturing method was investigated as described in this paper. This was achieved by using a laser energy density of 7.0 MW/cm2 to stabilize the melt pool formation and create sufficient penetration depth with 300 μm thickness foil. The highest yield strength (YS) and ultimate tensile strength (UTS) in the LFP-fabricated samples reached 111 ± 8 MPa and 128 ± 3 MPa, respectively, along the laser scanning direction. These samples exhibited greater tensile strength but less ductility compared to annealed Al-1100 samples. Fractographic analysis showed elongated gas pores in the tensile test samples. Strong crystallographic texturing along the solidification direction and dense subgrain boundaries in the LFP-fabricated samples were observed by using the electron backscattered diffraction (EBSD) technique.

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Section: Resultsmentioning

confidence: 99%

Aluminum Parts Fabricated by Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, and Mechanical Properties

Hung

Sutton

et al. 2020

Materials

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“…Due to rapid local solidification, the surface transformed and fine columnar microstructure was formed [12]. Moreover, as evident from Figure 4 high solidification rate during the LSA process caused the alloying elements of the particles to dissolve and mix within the melted layer and then formed fine precipitates [45], which however were still in the "under-aged" condition. The size of the resulting newly formed grains in the LMZ depend on the temperature of the melt during heating and cooling rate.…”

Section: Surface Morphology and Microstructural Analysismentioning

confidence: 99%

Energy Density Effect of Laser Alloyed TiB2/TiC/Al Composite Coatings on LMZ/HAZ, Mechanical and Corrosion Properties

Ravnikar

Trdan

Nagode

et al. 2020

Metals

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In the present work, TiC/TiB2/Al composite coatings were synthesized onto a precipitation hardened AlSi1MgMn alloy by laser surface alloying (LSA), using 13.3 J/mm2 and 20 J/mm2 laser energy densities. Microstructure evaluation, microhardness, wear and corrosion performance were investigated and compared with the untreated/substrate Al alloy sample. The results confirmed sound, compact, crackles composite coating of low porosity, with a proper surface/substrate interface. Microstructural analyses revealed the formation of extremely fine nano-precipitates, ranging from of 50–250 nm in the laser melted (LMZ) and large precipitates, accompanied with grain coarsening in the heat-affected zone (HAZ), due to the substrate overheating during the LSA process. Nonetheless, both coatings achieved higher microhardness, with almost 7-times higher wear resistance than the untreated sample as a consequence of high fraction volume of hard, wear resistant TiB2 and TiC phases inside the composite coatings. Further, cyclic polarization results in 0.5 M NaCl aqueous solution confirmed general improvement of corrosion resistance after LSA processed samples, with reduced corrosion current by more than a factor of 9, enhanced passivation/repassivation ability and complete prohibition of crystallographic pitting, which was detected with the untreated Al alloy.

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“…All samples presented the fracture in the FZ without any exception and micrographs of selected samples are exhibited in Figure 9. The failure mechanism corresponds to a ductile fracture, associated with the nucleation and growing of microcavities and coalescence of microholes [13,32]. It is noticeable that the nucleation centers in the cavity were promoted by the presence of nanoparticles whose morphology and size were heterogeneous.…”

Section: Fracture Behaviormentioning

confidence: 99%

“…In order to determine the elements which promotes the formation and distribution of precipitates during GMAW and the consequent affectation of mechanical properties of 6xxx alloys, several characterization techniques have been used. The hardening β"-phase is dissolved due to the heat input from welding procedure and it has been identified after GMAW by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) or Transmission electron microscopy (TEM) [12,13]. During GMAW, the HAZ is susceptible to the formation of β" and β precipitates grouped as needles and sticks because of high temperature (256-266 • C), leading to the formation of fragilization zones.…”

Section: Introductionmentioning

confidence: 99%

Comparative in Mechanical Behavior of 6061 Aluminum Alloy Welded by Pulsed GMAW with Different Filler Metals and Heat Treatments

Guzman

Granda‐Gutiérrez

Acevedo³

et al. 2019

Materials

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Precipitation hardening aluminum alloys are used in many industries due to their excellent mechanical properties, including good weldability. During a welding process, the tensile strength of the joint is critical to appropriately exploit the original properties of the material. The welding processes are still under study, and gas metal arc welding (GMAW) in pulsed metal-transfer configuration is one of the best choices to join these alloys. In this study, the welding of 6061 aluminum alloy by pulsed GMAW was performed under two heat treatment conditions and by using two filler metals, namely: ER 4043 (AlSi 5 ) and ER 4553 (AlMg 5 Cr). A solubilization heat treatment T4 was used to dissolve the precipitates of β"phase into the aluminum matrix from the original T6 heat treatment, leading in the formation of β-phase precipitates instead, which contributes to higher mechanical resistance. As a result, the T4 heat treatment improves the quality of the weld joint and increases the tensile strength in comparison to the T6 condition. The filler metal also plays an important role, and our results indicate that the use of ER 4043 produces stronger joints than ER 4553, but only under specific processing conditions, which include a moderate heat net flux. The latter is explained because Mg, Si and Cu are reported as precursors of the production of β"phase due to heat input from the welding process and the redistribution of both: β" and β precipitates, causes a ductile intergranular fracture near the heat affected zone of the weld joint.

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Microstructure and Mechanical Properties of Pulse MIG Welded 6061/A356 Aluminum Alloy Dissimilar Butt Joints

Cited by 77 publications

References 25 publications

Aluminum Parts Fabricated by Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, and Mechanical Properties

Aluminum Parts Fabricated by Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, and Mechanical Properties

Energy Density Effect of Laser Alloyed TiB2/TiC/Al Composite Coatings on LMZ/HAZ, Mechanical and Corrosion Properties

Comparative in Mechanical Behavior of 6061 Aluminum Alloy Welded by Pulsed GMAW with Different Filler Metals and Heat Treatments

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