Microstructural investigation of a metallic armor

ABSTRACT

Steel is still the most used material in the production of ballistic armor, especially military armor. These materials, when subjected to appropriate heat treatments, allow the improvement of their performance as ballistic shielding. The quenching and tempering heat treatments allow to obtain the tempered martensitic microstructure with high hardness without loss in toughness, antagonistic properties for the steels and fundamental for a shield. However, the choice of the chemical composition of the steel and / or inadequate heat treatments can generate microstructures that impair the mechanical properties mentioned above. This work aimed to present the analysis of the appearance of microstructures that affect the resistance of the ballistic shield material after the heat treatment of quenching and tempering at tempering temperatures of 310 °C; 425 °C and 610 °C. The microstructure of the material used in this work, after the thermal treatments, was investigated by means of electron and optical microscopy, as well as by X-ray diffraction, indicating microstructural changes in the studied material relevant to the ballistic properties. The tempering treatments presented in this work with higher temperatures did not reach the minimum hardness established, as a rule, for a ballistic material

Keywords Metallic armor; Thermal Treatments; Metallographic analysis