Ultrasonic-Assisted Laser Metal Deposition of the Al 4047Alloy

Abstract

Ultrasonic-assisted laser metal deposition(UALMD) technology was used to fabricate Al 4047 parts. The effect of the powder feeding laser power, remelting laser power and ultrasonic power on the relative density of the parts was investigated. The relative density, microstructure and mechanical properties of the specimens obtained by the optimized process parameters were compared with the corresponding properties of the cast alloys. The results showed that dense alloys with a maximum density of 99.1% were prepared using ultrasonic vibration and by remelting the previously deposited layer with the optimized processing parameters, and its density was almost equivalent to that of the cast parts. The microstructure of the samples using optimal laser parameters presented columnar Al dendrites and equiaxed Si particles at the boundary of each deposited layer, while the supersaturated Al solid solution was transformed into equiaxed crystal surrounded by fine fibrous Si phases at the center of the layer. Moreover, the size of the primary Al and the Si particles in the samples produced by UALMD was remarkably refined compared to that of the primary Al and Si particles in the cast structure, resulting in grain refining strengthening. The observed variation in the microstructure had an obvious impact on the tensile properties. The mechanical behavior of the deposit obtained by UALMD revealed superior tensile strength, yield strength and tensile ductility values of 227 ± 3 MPa, 107 ± 4 MPa and 12.2 ± 1.4%, which were approximately 51%, 38% and 56% higher than those of the cast materials, respectively.

Effect of Ultrasonic Vibration and Interpass Temperature on Microstructure and Mechanical Properties of Cu-8Al-2Ni-2Fe-2Mn Alloy Fabricated by Wire Arc Additive Manufacturing

“…Hence, we can predict that the temperature of the arc melting pool is high enough to re-melt the equiaxed dendrites region (Figure 4a), while the SDAs help to maintain the growth direction of primary dendrites in subsequent layers (Figures 3a1-b4 and 4f), and finally forms the epitaxial growth. Previous studies reveal that the microstructure of materials depends on both the nucleation condition and subsequent growth stage [19,26]. The UVA treatment WAAM at lower interpass temperature can hinder the growth of epitaxial columnar more effectively and promote the formation of new grains.…”

“…Eventually, WAAM parts with refined grains are obtained UVA treatment at a lower interpass temperature process during the nucleation stage. Previous studies reveal that the microstructure of materials depends on both the nucleation condition and subsequent growth stage [19,26]. The UVA treatment WAAM at lower interpass temperature can hinder the growth of epitaxial columnar more effectively and promote the formation of new grains.…”

“…The acoustic nonlinear effects (including specific cavitation and acoustic streaming) arising in ultrasonic vibration can influence the convection and solidification behaviors of the molten pool [18]. Hence, ultrasonic vibration has been effectively used in melting metal solidification processes such as casting [19,20], welding [21], cladding [22], additive manufacturing [23][24][25][26]. Wang et al [25] discovered that laser engineered net shaping of Inconel 718 with ultrasonic vibration could refine the microstructure, decrease micropore, improve homogeneity of chemical contents and shorten the size of Laves phases.…”

“…Wang et al [25] discovered that laser engineered net shaping of Inconel 718 with ultrasonic vibration could refine the microstructure, decrease micropore, improve homogeneity of chemical contents and shorten the size of Laves phases. Ultrasonic vibration was used to assist laser engineered net shaping to fabricate Fe-Cr stainless steel [23] and 4047 aluminum [26], which had analogous phenomena in reducing micropore and refining grains. However, there are no reported investigations on ultrasonic vibration assisted (UVA) treatment during the WAAM process of fabrication the NAB alloys parts.…”

Effect of Composition on the Mechanical Properties and Wear Resistance of Low and Medium Carbon Steels with a Biomimetic Non-Smooth Surface Processed by Laser Remelting

“…Then, the region is quickly solidified via heat conduction from the substrate, so the obtained microstructure is different from the matrix, and when the selected laser processing parameters are appropriate, the grain will be refined. The material's hardness is also much improved based on the pattern [16][17][18]. In this way, the non-smooth bionic structure with soft and hard phases is processed on the surface.…”