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The interaction between a projectile and metal-matrix composites (MMCs) was investigated in terms of macro cracking, petalling and particularly grain deformation of a matrix alloy at the hole section caused by the projectile at high velocity impact. Metal matrix composites were manufactured by squeeze casting using Al alloys reinforced with Al2O3 or SiC. Additionally, laminated composites with SiC particles and back side supported by Kevlar 49® were manufactured and their ballistic behavior tested. The composite and unreinforced Al alloy targets were subjected to ballistic impact with an armor piercing projectile of 7.62mm caliber at a speed in the range of 770-800 m/s. The macro examination focused on cracking and petalling after impact. The investigation of grain deformations of matrix alloy was conducted by light microscopy in the hole section created by the projectile. The hole section created by the projectile had different profiles. Around the hole sections, different grain deformation rates in different directions took place for reinforced and unreinforced Al alloys. Strong friction took place between the projectile and hole surface and the velocity of the projectile was decreased suddenly in the hole as it met the reinforcement particles in the composite body. These led to deformations of the projectile surface and grain surrounding the reinforcement. In the case of laminate composites, the laminates were fractured and deformed in the direction of projectile movement [ABSTRACT FROM AUTHOR]

The nondelamination characteristics of three-dimensional (3-D) braided composites under ballistic impact makes them possess considerable potential in ballistic protection applications. However, there are only a few references concerning the calculation of ballistic properties of these composites, and all are based on the continuum assumption of composite materials. In this paper, a refined quasi-microstructure model constructed with crossed inclined laminae of the same braided yarn with the same diameter and fiber volume fraction as in the 3-D braided composite at the actual microstructure level is established to analyze the ballistic penetration of 3-D braided composites target by a rigid projectile. The calculated results of the finite element analysis (FEA) are conservative to estimate the penetration resistance of the composite. From the acceleration-time history of the projectile and the damage morphology of the 3-D braided composite in FEA, it is indicated that the refined quasi-microstructure model can approximately simulate the real ballistic impact damage of these composites. The original ideas of this refined quasi-microstructure model are the scheme of decomposing the 3-D braided composite with the inclined lamina at its actual microstructure level and the adoption of constitutive equations of the reinforced fibers at a high strain rate. This model can also be extended to calculate the ballistic penetration of other 3-D textile preform-reinforced composites by rigid projectiles. [ABSTRACT FROM AUTHOR]