**5. Dynamic testing**

Several ballistic packages (**Figure 15**) were made for the testing of composite structures at high-velocity perforation, explosion, and high-velocity deformation. The packages have a sandwich structure, containing aluminum, steel, or ceramic plates or polymer HEA plate and, finally, aluminum plate again. The images from the firing room and the testing configuration are shown in **Figure 16**, and the experimental stand scheme for dynamic test is shown in **Figure 17**.

The ballistic packages undergoing tests for checking the bullet impact behavior were fastened to a wooden stand at a distance of 5 m from the machine-gun barrel's muzzle. The amount of powder in the cartridge shell was varied in order to obtain the desired initial velocity [15–19].

Two 7.62 × 39 mm incendiary armor-piercing bullets with initial velocities of 660 and 728 m/s, respectively, were fired at the targets. The ballistic package resisted punching for the first fire (**Figure 17a**) and then perforated at the second firing (**Figure 17b**).

The same procedure of dynamic testing, using 7.62 × 39 mm incendiary armorpiercing bullets at initial velocities of 723 and 728 m/s, respectively, was applied at

**151**

**Figure 17.**

*Characterization and Testing of High-Entropy Alloys from AlCrFeCoNi System for Military…*

the HEA-ceramic ballistic package. This type of ballistic package was perforated

The last procedure was applied using 7.62 × 39 mm incendiary armor-piercing bullets at initial velocities of 720 and 725 m/s, respectively, for dynamic testing of HEA-ceramic ballistic package. This type of ballistic package was entirely perfo-

*DOI: http://dx.doi.org/10.5772/intechopen.88622*

rated, in both cases (**Figure 19**).

*Ballistic packages prepared for dynamic tests.*

*Firing room and experimental stand for dynamic test.*

*HEA-steel ballistic package during dynamic tests (a) after the first firing and (b) after the second firing.*

**Figure 15.**

**Figure 16.**

both at the first and second cases (**Figure 18**).

*Characterization and Testing of High-Entropy Alloys from AlCrFeCoNi System for Military… DOI: http://dx.doi.org/10.5772/intechopen.88622*

the HEA-ceramic ballistic package. This type of ballistic package was perforated both at the first and second cases (**Figure 18**).

The last procedure was applied using 7.62 × 39 mm incendiary armor-piercing bullets at initial velocities of 720 and 725 m/s, respectively, for dynamic testing of HEA-ceramic ballistic package. This type of ballistic package was entirely perforated, in both cases (**Figure 19**).

**Figure 15.** *Ballistic packages prepared for dynamic tests.*

*Engineering Steels and High Entropy-Alloys*

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**5. Dynamic testing**

*SEM images of AlCrFeCoNix alloys.*

**Figure 14.**

**Figure 13.**

*SEM images of AlxCrFeCoNi alloys.*

firing (**Figure 17b**).

the desired initial velocity [15–19].

Several ballistic packages (**Figure 15**) were made for the testing of composite structures at high-velocity perforation, explosion, and high-velocity deformation. The packages have a sandwich structure, containing aluminum, steel, or ceramic plates or polymer HEA plate and, finally, aluminum plate again. The images from the firing room and the testing configuration are shown in **Figure 16**, and the

The ballistic packages undergoing tests for checking the bullet impact behavior were fastened to a wooden stand at a distance of 5 m from the machine-gun barrel's muzzle. The amount of powder in the cartridge shell was varied in order to obtain

Two 7.62 × 39 mm incendiary armor-piercing bullets with initial velocities of 660 and 728 m/s, respectively, were fired at the targets. The ballistic package resisted punching for the first fire (**Figure 17a**) and then perforated at the second

The same procedure of dynamic testing, using 7.62 × 39 mm incendiary armorpiercing bullets at initial velocities of 723 and 728 m/s, respectively, was applied at

experimental stand scheme for dynamic test is shown in **Figure 17**.

**Figure 16.** *Firing room and experimental stand for dynamic test.*

**Figure 17.** *HEA-steel ballistic package during dynamic tests (a) after the first firing and (b) after the second firing.*

#### **Figure 18.**

*HEA-ceramic ballistic package during dynamic tests (a) after the first firing (b) and after the second firing (c).*

**Figure 19.** *HEA-polymer ballistic package during dynamic tests. (a) after the first firing and (b) after the second firing.*
