Effects of crystal orientation on sintering and physical properties of Al3BC3

Ryosuke Maki, Shunta Matsumura, Yuta Yamawaki, Eri Takahashi, Satofumi Maruyama, Tomoyuki Maeda, Hatsuo Taira, Yoshihiro Kusano

The ternary metal borocarbide Al3BC3 forms plate-shaped particles having a crystallographic orientation along the c-axis and is expected to have low resistance to shear strain, similar to layered ternary carbides. This work demonstrates the first-ever synthesis of a textured polycrystalline Al3BC3 sample with anisotropic mechanical properties. The sintering characteristics of monophasic Al3BC3 were evaluated and a dense specimen with some degree of c-axis orientation was produced via spark plasma sintering. Nanoscale hardness and modulus maps of an Al3BC3 grain were generated using a nanoindenter and the hardness along the c-axis was shown to be approximately twice that in the basal plane direction. The elastic modulus along the c-axis was also approximately 1.25 times that along the basal plane, in good agreement with predicted anisotropic Young's moduli. Microstructural observations showed that fracture surfaces had laminated structures similar to those of layered ternary carbides, indicating potential applications as damage-tolerant materials.

Materials Research Bulletin