Effect of mechanical properties on the ballistic resistance capability of Al 2 O 3 -ZrO 2 functionally graded materials

Abstract Because Al 2 O 3 exhibits high strength and hardness, it is prevalently used as a ceramic material. ZrO 2 is often added to increase the toughness of such a material. Therefore, this study mixed Al 2 O 3 and ZrO 2 to formulate functionally graded materials (FGMs). four-layer and eleven-layer Al 2 O 3 -ZrO 2 FGM S were produced from Al 2 O 3 and ZrO 2 mixtures by sintering at 1500 °C. Moreover, testing sheets were created by mixing various ratios of Al 2 O 3 and ZrO 2 to analyze their fracture toughness and hardness. The results revealed the 90% Al 2 O 3 -10% ZrO 2 sheet to exhibit a hardness of 15.12 GPa, and the 50% Al 2 O 3 -50% ZrO 2 sheet to attain a fracture toughness as high as 4.7 MPa m 0.5 . The impact resistance test involved analyzing various types of testing sheets, including the four-layer Al 2 O 3 -(0%, 10%, 20%, 30%) ZrO 2 FGM, eleven-layer Al 2 O 3 -(0–100%) ZrO 2 FGM, 100% Al 2 O 3 composite material, 90% Al 2 O 3 -10% ZrO 2 composite material, 70% Al 2 O 3 -30% ZrO 2 composite material, and 50% Al 2 O 3 -50% ZrO 2 composite material. The ballistic tests showed that FGMs of the same areal density (4.64 g/cm 2 ) or thickness (11 mm) attained the highest energy absorption. The experimental results confirmed that FGMs can delay the formation and propagation of ceramic cones. Specifically, toughened alumina materials prevent the growth of radial and circumferential cracks, delay the formation of ceramic cones, decrease cones hitting against the back plane, and increase the penetrating resistant capability of the ceramic materials experiencing bullet impact, features important for applications in fields such as aerospace, aviation, automobile, the military industry, and biomedicine