Boron cracks the case on damage-resistant glass

Glass systems containing a high amount of boron demonstrate superior crack resistance, but the underlying mechanism remains elusive. Using virtual nanoindentation tests in classical molecular dynamics simulations, Liu et al. aim to better understand the cause of boron-containing glasses’ resistance to damage.

“Virtual nanoindentation tests provide the key missing information in experiments that is of critical importance for the rational design of glass with superior damage resistance,” said author Liping Huang.

The authors determined boron’s coordination number increases from three to four underneath an indenter during loading and returns, for the most part, to its initial state after unloading. This reversible coordination change plays a fundamental role in enhancing the crack resistance of glass by reducing stress buildup during loading and residual stress buildup after unloading.

“Damage-resistant glass is of paramount importance for a wide range of applications, such as personal electronics, automobiles, solar panels, buildings and submarine communications cables,” Huang said. “This study advances our fundamental knowledge on how glass cracks under sharp contact loading, such as dropping a smartphone with a glass cover onto a concrete floor.”

Though these virtual studies deepen the understanding of glass cracking behavior, future in situ characterizations are needed. Additionally, aluminum may also offer similar benefits to boron in improving crack resistance of glass, warranting further studies to explore its potential as well.

Source: “Understanding the response of aluminosilicate and aluminoborate glasses to sharp contact loading using molecular dynamics simulation,” by Haidong Liu, Binhhui Deng, Siddharth Sundararaman, Yunfeng Shi, and Liping Huang, Journal of Applied Physics (2020). The article can be accessed at https://doi.org/10.1063/5.0013555 .