PSI - Issue 77

M. Turhan et al. / Procedia Structural Integrity 77 (2026) 543–549

544

2

M.Turhan et al. / Structural Integrity Procedia 00 (2026) 000 – 000

create parts in this manner. The ASTM further classifies AM technologies into seven categories. These categories are distinguished by their specific processes, the types of materials, the types of machines involved, and the quality of the finished product, including its surface and geometric shape [1-8]. The work described here focuses specifically on Laser Powder Bed Fusion (L-PBF) technology. Although any part might be designed by CAD (Computer Aided Drawing) software, but the design might not be possible to print by L-PBF technology due to some challenges which are inherently within layer-wise building-up process of metal 3D printing. These include anisotropy (different properties in different directions), residual stress due to thermal cycles, the lack of fusion, so on. There is a plenty of factors which influence on the final part. Since each layer affects the layers before and after it, there is not one simple way to optimize all these factors at once. To improve the 3D printing process, it is favourable to focus on key parameters that directly influence the final part`s quality. These include laser power (the intensity of the laser`s energy), scanning speed (how quickly the laser moves), hatch spacing (the distance between laser paths), layer thickness (the depth of each layer of the powder). Additionally, both the part`s design and its support structure are crucial for a successful print [9-11]. HX, a nickel-chromium-iron-molybdenum alloy, is highly valued for its exceptional resistance to oxidation and stress-corrosion cracking, as well as its strength at high temperatures. These properties make it a desirable material for demanding applications in the aerospace, petrochemical, and energy sectors, including use in gas turbines, furnaces, and chemical processing systems. The unique properties of HX are a result of its composition. The combination of chromium and nickel enhances the material`s corrosion resistance, high-temperature performance, and overall mechanical strength. While chromium is key to its corrosion protection, nickel boosts its versatility, making it easier to form and weld for a variety of uses, also contributes to its sustainability [12-15]. This work’s main goal is to combine 3D printing technology’s capability and Hastelloy X material’s advantageous features through experimentally exploring the printability and mechanical properties of 3D-printed samples made from HX powder using L-PBF technology. The process involves a series of experiments where each print is a set up. There are adjustments for key parameters like the scanning strategy, process parameters, optimizing and improving support structures. The results from each print are analysed and used to improve the next one, aiming for more stable and reliable outcomes. By doing this so, to verify and compare the mechanical properties of the printed parts with industrial standards. Based on these findings from the experimental prints, it is proceeded to print the heat exchanger unit. This current work is an extension of the research conducted for author`s Master`s thesis, Investigation of printability and mechanical properties of Hastelloy X (HX) manufactured by Laser Powder Bed Fusion (L-PBF), Turhan, 2025. Specifically, the theoretical, practical background and test results are used and interpreted from that earlier work in chapter 2 and chapter 3 in this work. 2. Material and experimental procedures 2.1. Material The prints were carried out on the EOS M290 400 W 3D printer. During printing processes, argon is used as inert gas, re-coater blade is chosen as High-Speed Steel (HSS), and building platform temperature is kept as 80°C. The layer thickness of each recoated layer is 40 µm. In this work, EOS NickelAlloy HX powder is used to manufacture parts by L-PBF technology. Its chemical composition as shown by Table 1 and it has powder size distribution is ranging from 15 µm to 65 µm with a spherical morphology.

Table 1 The chemical composition of EOS NickelAlloy HX powder in weight percent

Element

Ni

Cr

Fe

Mo

W

Co

C

Si

Mn

S

P

B

Se

Cu

Al

Ti

Min Max

Balance 20.5

17 20

8

0.2

0.5 2.5

-

-

-

-

-

-

-

-

-

-

23

10

1

0.1

1

1

0.03

0.04

0.01

0.005

0.5

0.5

0.5