Elastic-plastic behavior of hot-pressed composite titanium diboride/alumina powders produced using self-propagating high-temperature synthesis

Advanced technologies for the synthesis and processing of ceramic materials are being developed to provide a route to lower manufacturing costs and increased reliability. Self-propagating high temperature synthesis (SHS) has been shown to be a feasible, potentially low cost technology to synthesize and form refractory ceramic materials such as titanium diboride and composite titanium diboride/alumina powders.; High strain rate impact tests on ceramic armor materials; titanium diboride (TiB{dollar}sb2{dollar}), silicon carbide (SiC), boron carbide (B{dollar}sb4{dollar}C), and alumina (Al{dollar}sb2{dollar}O{dollar}sb3{dollar}) have shown excellent resistance to penetration when compared with conventional rolled homogeneous metal armor (RHA).; The objective of this research was to determine if the static and dynamic properties of hot pressed powders produced using self-propagating high temperature synthesis (SHS) were competitive with the properties of hot pressed powders produced using conventional technologies. Further, it was an objective to determine the effects of projectile/target erosion, thermal and strain-rate phenomena on ceramic target penetration resistance.; The above objectives were accomplished by determining the elastic and plastic (inelastic) properties of hot pressed titanium diboride (TiB{dollar}sb2{dollar}) and composite titanium diboride/alumina (TiB{dollar}sb2{dollar}/Al{dollar}sb2{dollar}O{dollar}sb3{dollar}) powders produced using SHS technology. The results were compared to hot pressed, conventionally produced powders of carbothermic TiB{dollar}sb2{dollar}, polycrystalline Al{dollar}sb2{dollar}O{dollar}sb3{dollar}, and carbothermic TiB{dollar}sb2{dollar} manually mixed with polycrystalline Al{dollar}sb2{dollar}O{dollar}sb3{dollar}.; Quasi-static and dynamic properties were documented: and ballistic tests were conducted. Material properties were documented before and after the static and dynamic tests. Test results and material failure mechanisms were documented, analyzed and compared with reported values of TiB{dollar}sb2{dollar}, SiC, B{dollar}sb4{dollar}C and Al{dollar}sb2{dollar}O{dollar}sb3{dollar}. Resistance to penetration behavior was determined using Tate's model and Yatteu's relationships.; Results showed that static and dynamic behavior of materials produced using SHS technology exhibited properties that were as good as, or superior to, properties of materials produced using conventional processing technologies. The composite titanium diboride/alumina exhibited excellent resistance to high velocity penetration as compared with other ceramic armor materials. Thermal effects were not significant since the temperatures generated by penetration were approximately 300-500K. Strain-rate was significant since compressive strength increased as strain rate increased.