|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals, and Materials
||To Twin or Not to Twin in Boron Carbide
||Kelvin Xie, Fatih Toksoy, Vlad Domnich, James McCauley, Rich Haber, Kevin Hemker
|On-Site Speaker (Planned)
Boron carbide is an attractive material due to its low density and super hardness. Incorporating nanotwins into boron carbide may further improve the mechanical properties and ballistic performance. Here, we show that nanotwins can be engineered into boron carbide by two novel routes. The first method is to grow nanotwins into the starting B4C powders and then consolidate the powders to achieve dense nanotwinned samples. The second route is to start with twin-free powders and then grow twins during sintering by controlling the chemical stoichiometry. Boron carbide has a wide range of stable phases from B11C to B4C. Extensive planar defects (e.g. stacking faults and twins) were observed in the boron-rich boron carbide (e.g. B6.5C and B8.6C), but were not found in B4C. The origin of “asymmetric twins” in boron carbide will be discussed, and the influence of twins on the hardness and indentation fracture toughness will also be addressed.
||Planned: Stand-alone book in which only your symposium’s papers would appear (indicate title in comments section below)