Effect of laser surface remelting on the microstructure and properties of Al-Al2Cu-Si ternary eutectic alloy

Abstract

Bimodal ultrafine eutectic composites (BUECs) exhibit a good combination of strength and plasticity owing to a dual-hierarchy in eutectic length-scales in the microstructure. The present study investigates the variation of phase, morphology, feature length-scales and modality of microstructures obtained in a Al81Cu13Si6 (at. %) ternary alloy after laser surface remelting. A novel approach of varying component bimodal eutectic volume fractions by controlling the cooling rate of the laser solidification process has been presented. The volume fraction of the fine eutectic matrix has a profound effect on the flow strength. Laser remelted microstructures with volume fractions of the fine eutectic varying from 25 to 40% exhibiting compressive flow strengths ranging from 500 to 900 MPa have been obtained. The volume fraction of the fine eutectic decreased with cooling rate and completely ceased to exist at cooling rates greater than .

The novel low cost as-casting Al-based composites with high strength and ductility

“…(denoted by blue arrows) are randomly distributed in a nanoscale eutectic structures (denoted by yellow arrows). As reported in previous studies [16,20,21], the cellular structures are identified as binary eutectic of α-Al and θ-Al 2 Cu, the ultrafine ternary eutectic matrix is consisted of the α-Al, θ-Al 2 Cu and β-Si. Figure 1(c) reveals an obviously hypoeutectic structure of Al 88 Cu 8 Si 4 alloy.…”

Enhanced Tensile Plasticity in Ultrafine Lamellar Eutectic Al-CuBased Composites with α-Al Dendrites Prepared by Progressive Solidification

“…To block the high localized shear deformation, some inhomogeneous microstructures such as the micron-scale soft and ductile dendritic phase have been introduced into the nano/ultrafine matrix [11][12][13][14][15][16][17][18][19]. Although these nano/ultrafine structured composites exhibited an excellent compressive plasticity, they still exhibited very limited macroscopic plasticity under tensile stress.…”

Mechanical behavior of nanocomposites

“…Laser-based processing, such as direct metal deposition and other related approaches, has significant potential in the synthesis of designed metallic nanocomposites of the future. 49,50 Likewise, 3D printing 51 has shown promise through high spatial fidelity, flexibility, and high throughput to process large-scale bioinspired architectured materials with improved mechanical properties.…”