International Cooperation

Plastic Deformation Mechanisms of Ceramic Nanowires

Advancement has been achieved in understanding the large plastic deformation of ceramics at room temperature. The research was performed by an international team consisting of researchers from the CAS State Key Laboratory of Nonlinear Mechanics, Beihang University and City University of Hong Kong in China, Curtin University and the University of Sydney in Australia, and Brown University in the US. The scientists noted that microstructures of SiC NWs synthesized in laboratories usually consist of cubic-structured segments, stacking defects, twins and intergranular amorphous films. These structures exhibit various side morphologies. Based on molecular dynamics simulations, it is shown that the large plastic deformation occurs as a result of the anti-parallel sliding of cubic-structured grains along intergranular amorphous films inclined at an angle of 19.47o with respect to the NW axis. The intergranular amorphous films dominated plasticity differs with mechanism in metals or alloys due to dislocation activities and is thermally stable below 700 K. Also revealed is the wide dispersion of mechanical properties such as Young’s modulus, strength and elongation due to the anisotropy of the microstructures. The group’s results offer guidance on the microstructural design of ceramics with tailored mechanical properties. The relevant results have been published in Nanotechnology, 23 (2012), 025703.