*2.2. Equipment*

Laser powder bed fusion was carried out on an EOS M280 industrial unit (EOS GmbH, Krailling, Germany) and an ALAM experimental laser powder bed fusion setup (MSTU Stankin, Moscow, Russia) [61,62] equipped with the laser source of continuous radiation LK-200 (IPG LASER GMBH, Fryazino, Russia), equipped with two attenuators, B-Cube and C-Varm (Coherent, Santa Clara, CA, USA), and a Focal-piShaper (πShaper, Berlin, Germany). The experimental unit had the following technical parameters: a wavelength of 1070 nm, a beam divergence of 0.2◦, maximum power *Pl.max* of 200 W (Figure 1).

**Figure 1.** Experimental setup, where *CCD* is a charge-coupled device, *IR* is infrared.

The powders were sifted using an analytical sieving machine AS200 basic (Retsch, Dusseldorf, Germany) with test sieves of 40 μm by ISO 3310-1 and dried by a vacuum oven VO400 (Memmert GmbH + Co. KG, Schwabach, Germany) before processing. The powder drying removed the excess air and contributed to a better powder density in the layers.

A parametric analysis of experimental work was carried out on the ALAM and EOS M 280 setup to select the optimal modes' manufacturing samples.

The chosen laser powder bed fusion factors at the EOS M280 and ALAM setups for growing solids of 20 mm × 20 mm × 20 mm samples for five pieces for each of experimental set are presented in Table 2. For tensile tests, 15 flat specimens were used in accordance with GOST 11,701 (Figure 2). The specimens were grown in the direction of the *Z* axis, the angle of inclination of the longitudinal axis of the specimen to the printing plane was 0◦.


**Figure 2.** Specimens for tests: (**a**) schemes of specimens for hardness tests; (**b**) schemes of specimens for tensile tests; (**c**) general view of tensile test specimens; (**d**) destroyed specimens.

(**c**) (**d**)

The quenching and tempering of the samples were produced in a chamber furnace CWF 12/23 with maximal temperature of 1200 ◦C and capacity of 23 L manufactured by Carbolite Gero (Hope Valley, UK).

The comparison of the hardness and wear resistance test results were done on the casted samples in the state of delivery according to TU 14-1-377-72 produced by LLC "Chelyabinsk Forging—Mechanical Plant" (Chelyabinsk, Russia).
