RT Journal Article
SR Electronic
T1 Tuning the deformation mechanisms of boron carbide via silicon doping
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP eaay0352
DO 10.1126/sciadv.aay0352
VO 5
IS 10
A1 Xiang, Sisi
A1 Ma, Luoning
A1 Yang, Bruce
A1 Dieudonne, Yvonne
A1 Pharr, George M.
A1 Lu, Jing
A1 Yadav, Digvijay
A1 Hwang, Chawon
A1 LaSalvia, Jerry C.
A1 Haber, Richard A.
A1 Hemker, Kevin J.
A1 Xie, Kelvin Y.
YR 2019
UL http://advances.sciencemag.org/content/5/10/eaay0352.abstract
AB Boron carbide suffers from a loss of strength and toughness when subjected to high shear stresses due to amorphization. Here, we report that a small amount of Si doping (~1 atomic %) leads to a substantial decrease in stress-induced amorphization due to a noticeable change of the deformation mechanisms in boron carbide. In the undoped boron carbide, the Berkovich indentation–induced quasi-plasticity is dominated by amorphization and microcracking along the amorphous shear bands. This mechanism resulted in long, distinct, and single-variant shear faults. In contrast, substantial fragmentation with limited amorphization was activated in the Si-doped boron carbide, manifested by the short, diffuse, and multivariant shear faults. Microcracking via fragmentation competed with and subsequently mitigated amorphization. This work highlights the important roles that solute atoms play on the structural stability of boron carbide and opens up new avenues to tune deformation mechanisms of ceramics via doping.