|About this Abstract
||Materials Science & Technology 2020
||Ceramics and Glasses Simulations and Machine Learning
||The Role of Pore Pattern on The Ductility Enhancement of Crystalline Silicon Nitride Nanoporous Membranes
||Ali K. Shargh, James L. McGrath, Niaz Abdolrahim
|On-Site Speaker (Planned)
||Ali K. Shargh
Silicon nitride nanoporous membranes are extremely permeable silicon based ceramics that were first developed at University of Rochester in 2014. Recent studies show that those nanostructures possess sudden failure with negligible ductility which limits their biomedical applications. Here, we use molecular dynamics simulations to investigate the role of pore pattern on failure behavior of crystalline nanostructures. With change of pore pattern, nanostructures show three different mechanical behaviors with distinct fracture surfaces upon loading. A key outcome is observation of pronounced enhancement in ductility upon arranging diagonal neighbor pores along the preferred slip direction. In this case, a network of embryonic shear bands is formed in the nanostructure which leads to ductility enhancement. The origin of this enhancement is found to be associated with a large area with compressive stress in front of the propagating crack that opposes the crack opening and distort it toward a zigzag path which delayed fracture.