Supercomputers Reveal True Strengths of Some Zirconia Ceramics

Published May 18, 2020

[Enlarge] The findings provided significant insight into the behavior of twin boundaries and pre-existing defects in shape memory ceramics. These simulations illustrate: (a) Stress-strain relations of four-, five- and seven-twin boundaries (TB) YSTZ nanopillars. The elastic, strain-hardening, and strain softening/hardening regions of four- and five-TB pillars are denoted by shadows with different colors. The seven-TB pillar regions shift at about 1% strain to the right. Snapshots in (b–n) correspond to strain points b-n (a). Atoms in b–n are colored by coordination number (CN). Blue and green atoms represent tetragonal and monoclinic phases, respectively. Atoms with other colors stand for disarranged structures.  Credit: N. Zhang and M. Asle Zaeem, Colorado School of Mines

By Kimberly Mann Bruch, SDSC Communications

For thousands of years, humans have produced ceramics by simply combining specific minerals with water or other solvents to create ceramic slurries that cure at room temperature and become some of the hardest known materials. In more recent times, zirconia-based ceramics have been useful for an array of applications ranging from dental implants and artificial joints to jet engine parts.

Researchers from the Colorado School of Mines have been using multiple supercomputers – Comet at the San Diego Supercomputer Center (SDSC), Stampede2 at the Texas Advanced Computing Center (TACC), and Bridges at the Pittsburgh Supercomputing Center (PSC) – to study certain characteristics of zirconia. The team recently published their findings in Journal of the European Ceramic Society.

According to corresponding author Mohsen Asle Zaeem, a mechanical engineering professor at the Colorado School of Mines, the study focused on creating supercomputer simulations that show zirconia-based ceramic’s ability to withstand harsh conditions as well as the extreme limits of fracture and fatigue.

“By using large-scale atomistic simulations, these simulations revealed to us how specific type nanoscale structures, twin boundaries, and pre-existing defects control the mechanical behavior and the corresponding plastic deformation of an advanced shape memory ceramic called yttria-stabilized tetragonal zirconia or YSTZ,” explained Asle Zaeem. “Some important applications, such as jet engines, require advanced materials that can perform reliably at extreme conditions. Shape memory ceramics have shown superior properties at those higher temperatures such as high strength and excellent oxidation/corrosion resistance. Addressing their deformation, fracture, and fatigue limitations will open the door for creating the next generation of high-temperature materials.”

This research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, (DE-SC0019279).

About SDSC

The San Diego Supercomputer Center (SDSC) is a leader and pioneer in high-performance and data-intensive computing, providing cyberinfrastructure resources, services, and expertise to the national research community, academia, and industry. Located on the UC San Diego campus, SDSC supports hundreds of multidisciplinary programs spanning a wide variety of domains, from astrophysics and earth sciences to disease research and drug discovery. In late 2020 SDSC will launch its newest National Science Foundation-funded supercomputer, Expanse. At over twice the performance of Comet, Expanse supports SDSC’s theme of ‘Computing without Boundaries’ with a data-centric architecture, public cloud integration, and state-of-the art GPUs for incorporating experimental facilities and edge computing.