Characterization and Evaluation of TiB2-AlN Composites for Armor Applications.

摘要

Seven composites with titanium diboride (TiB2) and aluminum nitride (AlN) of varying compositions were consolidated by hot pressing. The compositions examined were 30-vol% TiB2 / 70-vol% AlN, 50-vol% TiB2 / 50-vol% AlN, and 70-vol% TiB2 / 30-vol% AlN. One TiB2 powder was used with three AlN powders: two with finer particle sizes and one with larger particle sizes. All the composites were consolidated to near full density. Microstructural, mechanical-property, and ballistic depth-of-penetration (DOP) evaluations were conducted. Theoretical phase calculations were used to determine and explain the formation of the detected impurities. The flexural strength and mass efficiency results from the four-point bend and DOP tests, respectively, showed that most of the composite compositions performed better than either monolithic TiB2 or AlN material. The increase in fracture toughness from microcrack formation and crack bridging is believed to be the cause of the synergistic effects.