Distortion-induced Strengthening and Toughening

Ripples were characterized in sintered hBN using HRTEM and strain map analysis. Atomistic models of stable ripples of different shapes in hBN were created. MD simulations showed significant strengthening and toughening effects due to ripples in both multilayer and single layer hBN, accompanied by increase in bond strength. Detailed local principal stress calculations and distortion analysis were done to compare the strengthening mechanism between different rippled hBN structures. The extent of strengthening and toughening in rippled hBN governed by extent of increase in distortion (caused by ripples) in the form of structural asymmetry. Calculation of the bond strength in AC and ZZ directions of different structures indicated a novel distortion-induced bond-strengthening characteristic in hBN.