Fig. 1. Characteristics of GH3536 alloy powder. (a) Powder morphology; (b) powder particle size distribution

Fig. 2. Schematics of sample forming. (a) Diagram of quadruple-laser L-PBF forming; (b) L-PBF forming samples; (c) schematics of single-laser processing region and overlap region

Fig. 3. Optical micrographs of melting tracks on sample upper surface. (a) Single-laser processing region; (b) dual-laser processing region; (c) quadruple-laser processing region

Fig. 4. Relative densities and optical micrographs of different samples

Fig. 5.

SEM images of different samples. (a) (c) Low magnification; (d) (i) high magnification

Fig. 6.

EBSD results of samples formed by different laser beams along horizontal direction. (a) (c) Grain orientation; (d) (f) texture

Fig. 7. Misorientation angle distributions of different samples. (a) Single-laser processing sample; (b) dual-laser processing sample; (c) quadruple-laser processing sample

Fig. 8.

Residual stress of samples formed by different laser beams. (a) (c) XRD patterns of (220) crystal planes at different tilting angles; (d) (f) d versus sin²Ψ

Fig. 9. Tensile properties of different samples. (a) Stress-strain curves along horizontal direction; (b) yield strength, ultimate tensile strength and elongation rate along horizontal direction

Fig. 10. Differences between single-laser forming area and multi-laser forming area. (a)(c) Laser action zones and molten pools; (b)(d) grain characteristics and defects