Control of Crystallographic Texture and Mechanical Properties of Hastelloy-X via Laser Powder Bed Fusion

Abstract

The influence of various laser powder bed fusion (LPBF) process parameters on the crystallographic textures and mechanical properties of a typical Ni-based solid-solution strengthened alloy, Hastelloy-X, was examined. Samples were classified into four groups based on the type of crystallographic texture: single crystalline-like microstructure with <100>//build direction (BD) (<100>-SCM), single crystalline-like microstructure with <110>//BD (<110>-SCM), crystallographic lamellar microstructure (CLM), or polycrystalline microstructure (PCM). These four crystallographic textures were realized in Hastelloy-X for the first time here to the best of our knowledge. The mechanical properties of the samples varied depending on their texture. The tensile properties were affected not only by the Schmid factor but also by the grain size and the presence of lamellar boundaries (grain boundaries). The lamellar boundaries at the interface between the <110>//BD oriented main layers and the <100>//BD-oriented sub-layers of CLM contributed to the resistance to slip transmission and the increased proof stress. It was possible to control a wide range of crystallographic microstructures via the LPBF process parameters, which determines the melt pool morphology and solidification behavior.

Excellent strength–ductility balance of Sc-Zr-modified Al–Mg alloy by tuning bimodal microstructure via hatch spacing in laser powder bed fusion

“…Specifically, numerous metallic alloys used today cannot be manufactured through LPBF because the melting and solidification dynamics of the fabrication process conducted at a rapid cooling rate ($10 6 K/s) lead to the formation of undesirable microstructures, such as cracks and hot tears [5]. Currently, stainless steel [6][7][8], Ti-based alloys [9,10], Ni-based alloys [11,12], and Al-based alloys [13][14][15] are fabricated by LPBF. Albased alloys include near-eutectic Si-containing alloys, such as AlSi12 [16] and AlSi10Mg [17], and Sc-and/or Zr-modified Al-Mg-based alloys (typically referred to as Scalmalloy) have been applied for the LPBF process [18,19].…”

Crystallographic texture configured by laser powder bed fusion additive manufacturing process: a review and its potential application to adjust mechanical properties of metallic products

“…According to Suwas and Ray [2], such a level of orientation is characterized by having at least 30 to 40% of the material formed by crystals ordered in a specific <uvw> which can Based on this scenario, this review article offers some highlights and trends to explain crystallographic texture control covering AM processes employing laser powder bed fusion (LPBF). The choice of AM by LPBF is justified because this process can not only generate strong textures in metallic products [6,12,13], but also because it is a well-established, highly versatile, and relatively accessible process [9,14,15]. Therefore, AM by LBPF is an important candidate process to control the crystalline texture and, indeed, for the definition of physical and mechanical properties normally not manipulated in metallic products such as stiffness.…”

“…At the same time, the use of Additive Manufacturing (AM) processes has grown as a solution to produce geometrically complex products (Figure 1) that are not so simple to obtain through other manufacturing processes [8][9][10]. Furthermore, some variants of AM have shown the capability to induce strong crystalline texture in metallic materials, especially using energy beams and oriented solidification [11][12][13].…”

Effects of Recrystallization on Tensile Anisotropic Properties for IN738LC Fabricated by Laser Powder Bed Fusion

“…Vertical samples (Figure 1c, called "Zsample(s)") of 8 mm diameter and 60 mm height (z-direction) and horizontal samples (Figure 1d, called "X-sample(s)") with dimensions 60 mm (x-direction), 8 mm (y-direction), and 8 mm (z-direction) were built directly on the base plate and then cut off in the vicinity of the plate. To determine the effect of the microstructure itself on mechanical properties, the volumetric energy density E vol [J/mm 3 ] was set to 72.9 J/mm 3 [37], which has been reported to produce dense products without lack-of-fusion and keyhole-type defects [26]. To handle the x−y plane isotropically, the rotation scanning strategy [38] was employed, in which bidirectional laser scanning was rotated by 67 • layer by layer.…”

“…results in a variety of distinct microstructures, including single crystalline-like microstructures, crystallographic lamellar microstructures, and polycrystalline microstructures [21][22][23][24]. These microstructures, uniquely obtained by the LPBF process, provide Crystals 2022, 12, 842 2 of 14 excellent oxidation resistance [25], enhance corrosion resistance [5,22], and enable control of the mechanical properties [23,26,27].…”