Spark plasma sintering of boron carbide composite for defense application

• Main Author: Png, Wee Chun
• Other Authors: Alfred Tok Iing Yoong
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials::Defence materials
• Online Access: http://hdl.handle.net/10356/55792
• Institution: Nanyang Technological University

Boron carbide is a very attractive material for use in armour applications because of the high hardness and the relatively low density it possesses. However, the difficulties in consolidating the material present a huge hurdle to overcome. Using conventional consolidation techniques, high sintering temperature and long sintering time are needed to achieve a near full-densification. But, by using spark plasma sintering (SPS), the sintering temperature and time can be greatly reduced. The ballistic performance of boron carbide in armour application has also been hard to establish, due to the many variables involved, such as projectile velocity, types of threat, geometry of the ceramic, etc. The Depth of Penetration (DOP) test was found to be quite satisfactory for evaluating the ballistic performance of boron carbide. In this study two boron carbide powder of different grain size were sintered at a temperature of 1850 ○C using the SPS technique. The sintered boron carbide tiles were then evaluated for ballistic performance against a tungsten long-rod penetrator, using the standard DOP test method. It was found that the mass efficiency of the tile increases with tile thickness at a projectile velocity of 1,000 m/s. At a higher projectile velocity of 1,400 m/s, the mass efficiency of the tile decreases with increasing tile thickness. The mass efficiency of the tiles was also found to be increasing when the projectile velocity increases from 1,000 to 1,400 m/s. It was found that the ballistic efficiency of the tile decreases with wider grain size distribution. It was also determined that the ballistic performance of the boron carbide tile which had a layered arrangement in armour design showed a marked improvement over the conventional homogeneous boron carbide tile.