Design and impact resistant analysis of functionally graded Al2O3-ZrO2 ceramic composite

Gradient concept is one of the solutions in advanced material design and structure control. Functionally graded materials (FGMs) are materials which change their composition, constitution or structure continuously along the direction of thickness; the property and function of those materials appear as changeable gradient characteristics. In this research, powder metallurgy method was used to make the functionally graded Al2O3-ZrO2 composite, which was backed with 6061-T6 aluminum alloy plate. For comparing purpose, we also make multilayer Al2O3-ZrO2 composite and pure Al2O3 composite under the same areal density. Based on NIJ IV standard, ballistic test was executed on the three kinds of samples by using 0.30 '' armor piercing projectile (AP). Finite element software ANSYS/LS-DYNA was also used to simulate stress distribution and fracture of these composites under impact. It was shown from ballistic test that FGM had the best impact resistant performance. Normally, multilayer ceramic structure will be fractured after impact because of the tensile wave caused by the interlayer. Through SEM observation, delamination was not found in the interlayer of FGM. This phenomenon reduced the tensile wave occurred in the interface between layers and delayed the crack propagation, resulting in a higher ballistic resistance capability structure. (C) 2015 Elsevier Ltd. All rights reserved.