| Modern armors have been developing in the direction of compounding,lightweight and anti multi projectile attack,in order to deal with the threat of armor piercing weapons with stronger armor piercing power and damage effect.Traditional double-layer ceramic panel/backplate armor and functional gradient armor are difficult to meet the above requirements at the same time,while metal encapsulated ceramic armor unit opens up a new direction for the design of composite armors.In this paper,a variety of metal encapsulated ceramic balls composite armors were successfully prepared by pressure infiltration method for the first time.Anti multiple projectile attack performance and protection performance of composite armors were verified by anti-12.7 mm armor piercing projectile experiment.The penetration process,anti-projectile mechanism and influencing factors of anti-penetration performance of metal encapsulated ceramic balls composite armors were described by numerical simulation.The main work and research results were summarized as follows:(1)Based on ballistic yaw effect,shell bionic toughening mechanism and restraint effect,a variety of metal encapsulated ceramic balls composite armors were designed and prepared.Anti-penetration experiment results showed that all composite armors had excellent anti multi projectile strike performance,the damage area was limited to near the impact point,and the minimum effective protective area density was 106.5 kg/m~2.(2)The preparation procedure of metal encapsulated ceramic balls composite armors by pressure infiltration method mainly included the steps of design and processing of restraint layer,assembly of infiltration components,high temperature pressure infiltration and post-treatment.The infiltration mode adopted forward infiltration and the skeleton was arranged horizontally.Main process parameters were summarized as follows:preheated 6061 aluminum alloy and TC4 titanium alloy skeleton at 580℃～590℃and620℃,melting temperature of 6063 aluminum alloy was between 720℃and 740℃,infiltration pressure was between 4 MPa and 6 MPa holding for 6 min～10 min,and then keep warm in furnace for 30 min.(3)Anti-penetration experiment of 12.7 mm armor piercing projectile was carried out on prepared metal encapsulated ceramic balls composite armors,The damage of bullet and targets was analyzed.The arrangement of ceramic balls,properties of encapsulated metal and backplate materials on anti-ballistic performance of composite armors were analyzed and compared.The experimental results showed that all ceramic ball arrangements could resist the penetration of armor piercing projectile under the reasonable configuration of packaging metal and backplate.The anti-penetration performance of targets with TC4 titanium alloy as constraint layer was better than that with 6061 aluminum alloy as constraint layer.And PE fiberboard had higher kinetic energy absorption efficiency than 6061 aluminum alloy.(4)Finite element models of armor piercing projectile penetrating metal encapsulated ceramic balls composite armors were established.The penetration process could be divided into five stages:no contacting,penetration of the first layer ceramic balls,penetration of the second layer ceramic balls,penetration of backplate and the failure of backplate.Bullets had the highest kinetic energy absorption efficiency when they hit multiple closely arranged ceramic balls in the first layer,while the lowest kinetic energy absorption efficiency was obtained when they hit a single ceramic ball in the first layer.Packaging metal had a strong constraint effect on ceramic balls,forcing them to consume the kinetic energy of bullets more fully.That’s the reason why targets with TC4 titanium alloy as the constraint layer had better anti penetration performance.Numerical simulation results showed that the kinetic energy absorption efficiency of backplates under the same area density could be ranked as PE>6061 Al>6061 Al+PE,but the model parameters of PE may be underestimated. |
PDF Full Text Request