Effect of scanning strategy on texture formation in Ni-25 at.%Mo alloys fabricated by selective laser melting

Crystallographic Features of Microstructure in Maraging Steel Fabricated by Selective Laser Melting

“…The primary solid phase (γ phase in the studied composition as indicated in Figure 7) is observed to form at the interface between the solid and liquid phases and grows to the center of the melt pool (the hottest point under the laser irradiation) in solidification (Figure 8a), as reported in the literature [16,17]. The γ grains solidify along the preferential <001> solidification direction, as reported in other fcc metals (Ni [26,27] or Al alloys [16][17][18]) that have been fabricated using the SLM process. The preferential solidification direction can explain the observed {001} texture of the retained γ phase (Figure 8e).…”

“…In the studied composition, the initial solid phase is γ (fcc) below 1440 • C, whereas a γ single-phase region forms below the solidus temperature of approximately 1400 • C, and has a wide temperature range from 800 • C to 1400 • C. Below 800 • C, µ-Fe 7 Mo 6 phase appears and then α (bcc) phase form at lower temperature than 650 • C. The thermodynamic calculation assesses γ phase initially forms in liquid (L) phase. The assessment indicates the γ grains solidifying in the direction of the hottest point of the melt pool, considering the <001> preferential solidification direction of the fcc solid phase [25] as well as other fcc metals (Ni [26,27] or Al alloys [16][17][18]). This result is consistent with the observed retained γ grains oriented at <001> along the Z direction ( Figure 5).…”

Crystallographic Orientation Control of 316L Austenitic Stainless Steel via Selective Laser Melting

“…In the X-scan strategy, ± 45° cell growth and the corresponding single crystalline-like texture with {011} orientation in the build direction generally occurred as was previously well-documented. 3,4) The formation of CLM was achieved by appropriate modification of the laser condition based on the single-crystalline formation. 13) However, the single crystalline-like texture with {001} orientation in the build direction is reported for the first time under the X-scan strategy in SLM.…”

“…2(a)). The X-scan strategy has been clarified to be beneficial in producing a single crystalline-like texture 3,4,11) because of the fixed laser scanning direction and the resultant homogenous thermal flux in each melt pool. In this study, the build direction was defined as the z-direction, and the direction orthogonal to the x-and z-directions was defined as the y-direction ( Fig.…”

“…Taking advantage of such features of AM, metal AM technology has been applied to the fabrication of products with hollow structures, three-dimensional complex porous bodies, and tailor-made products, among others. 1,2) Meanwhile, in recent studies, metal AM has emerged as a methodology for controlling the crystallographic texture of metallic materials [3][4][5] in addition to controlling the shape of products. Crystallographic texture, which is an important material parameter for metallic materials, is a major factor that affects the functionality of a product, independent of shape parameters.…”