Assessment of the Impact Resistance of a Composite Material with EN AW-7075 Matrix Reinforced with α-Al2O3 Particles Using a 7.62 × 39 mm Projectile

Adam Kurzawa; Dariusz Pyka; Krzysztof Jamroziak; Marcin Bajkowski; Miroslaw Bocian; Mariusz Magier; Jan Koch

doi:10.3390/ma13030769

Assessment of the Impact Resistance of a Composite Material with EN AW-7075 Matrix Reinforced with α-Al₂O₃ Particles Using a 7.62 × 39 mm Projectile

Materials (Basel). 2020 Feb 7;13(3):769. doi: 10.3390/ma13030769.

Authors

Adam Kurzawa¹, Dariusz Pyka², Krzysztof Jamroziak², Marcin Bajkowski³, Miroslaw Bocian², Mariusz Magier³, Jan Koch⁴

Affiliations

¹ Department of Lightweight Elements Engineering, Foundry and Automation, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, Smoluchowskiego 25, 50-370 Wroclaw, Poland.
² Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, Smoluchowskiego 25, 50-370 Wroclaw, Poland.
³ Institute of Mechanics and Printing, Faculty of Production Engineering, Warsaw University of Technology, Narbutta 85, 02-524 Warsaw, Poland.
⁴ Wroclaw Center for Technology Transfer of Wroclaw University of Science and Technology, Smoluchowskiego 28, 50-372 Wroclaw, Poland.

Abstract

The paper presents the results of studies on the effects of shooting composite materials produced by pressure infiltration with the EN AW-7075 alloy as a matrix and reinforcement in the form of preforms made of α-Al₂O₃ particles. Composite materials were made with two reinforcement contents (i.e., 30% and 40% vol. of α-Al₂O₃ particles). The composites produced in the form of 12 mm thick plates were subjected to impact loads from a 7.62 × 39 FMJ M43 projectile fired from a Kalashnikov. The samples of composites with different contents of strengthening particles were subjected to detailed microscopic examination to determine the mechanism of destruction. The effect of a projectile impact on the microstructure of the material within the perforation holes was identified. There were radial cracks found around the puncture holes and brittle fragmentation of the front surfaces of the specimens. The change in the volume of the reinforcement significantly affected the inlet, puncture and outlet diameters. The observations confirmed that brittle cracking dominated the destruction mechanism and the crack propagation front ran mainly in the matrix material and along the boundaries of the α-Al₂O₃ particles. In turn, numerical tests were conducted to describe the physical phenomena occurring due to the erosion of a projectile hitting a composite casing. They were performed with the use of the ABAQUS program. Based on constitutive models, the material constants developed from the identification of material properties were modelled and the finite element was generated from homogenization in the form of a representative volume element (RVE). The results of microscopic investigations of the destruction mechanism and numerical investigations were combined. The conducted tests and analyses shed light on the application possibilities of aluminium composites reinforced with Al₂O₃ particles in the construction of add-on-armour protective structures.

Keywords: ballistic resistance; composite materials; computational modelling; dynamic loads; squeeze casting.