Peter Liaw - Academia.edu (original) (raw)

Papers by Peter Liaw

Journal of Iron and Steel Research International, 2016

Materials Science Forum, Jun 1, 2011

Acta Metallurgica Sinica (english Letters), Apr 10, 2020

Applied Physics Letters, 2021

High-entropy alloy is an alloy design concept without a principal component. This concept not onl... more High-entropy alloy is an alloy design concept without a principal component. This concept not only refers to the complexity of alloy compositions but also means that when the high-entropy alloy transits from a high-energy state to low-energy state, there will be more intermediate metastable states. Corresponding to different states are the changes in the degree and manner of order in the microstructure. In this study, we used machine learning to combine elemental characteristics with long-term ordering and established 87% of prediction accuracy. This data-driven method can correlate elemental characteristics and metastable states and accelerate the discovery of potential compositions.

Science, 2021

High-entropy herringbone alloy Eutectic high-entropy alloys have a dual phase structure that coul... more High-entropy herringbone alloy Eutectic high-entropy alloys have a dual phase structure that could be useful for optimizing a material’s properties. Shi et al . found that directional solidification of an aluminum-iron-cobalt-nickel eutectic high-entropy alloy created a herringbone-patterned microstructure that was extremely resistant to fracture (see the Perspective by An). The structure contained lamellae of hard and soft phases, and the cracks that formed in the hard phase were arrested at the boundary of the soft phase. This, along with stress transfer, allowed a tripling of the maximal elongation while retaining high strength. —BG

Scripta Materialia, 2021

Abstract Plastic instability manifested as the serrated flow on stress-strain curves of metal all... more Abstract Plastic instability manifested as the serrated flow on stress-strain curves of metal alloys is generally detrimental to their processing and manufacturing. The flow serration in the HfNbTaTiZr alloy is reported in the present work and its dependence on temperatures (573-823K) and strain rates (5 × 10−5 s−1-1 × 10−3 s−1) is investigated with experiments. The notable transition of the onset strain of the serrated flow from a declining (normal behavior) to rising (inverse behavior) trend with increasing temperature at applied strain rates is modeled successfully with a theoretical framework. The success of the model in predicting the onset strain as a function of temperature and strain rate represents a possibility of theoretically constructing a process window for the alloy under examination and beyond.

Materials Science and Engineering: A, 2019

Abstract For the present work, the Zr55Cu30Ni5Al10 (atomic percent) bulk metallic glass underwent... more Abstract For the present work, the Zr55Cu30Ni5Al10 (atomic percent) bulk metallic glass underwent room-temperature compression experiments in both the constrained and unconstrained conditions. For the constrained condition, samples were exposed to strain rates ranging from 2 × 10−5 s−1 to 2 × 10−3 s−1, while for the unconstrained case, the rates varied between 5 × 10−5 s−1 and 2 × 10−3 s−1. The serrated flow was modeled and analyzed using the refined composite multiscale entropy algorithm. Findings indicate that the complexity of the serration behavior increased with respect to the strain rate for both conditions. The increase in the complexity with increasing the strain rate is thought to be linked to a rise in the number of defect interactions that occur in the alloy during plastic deformation. Results also indicate that for a strain rate of 2 × 10−3 s−1, the complexity of the serrated flow was the highest in the constrained condition, which corresponds to higher spatiotemporal correlations between slipping weak spots during a serration event. The microscopy results combined with the complexity analysis support the idea that the serration events, which correspond to defect interactions, are more spatially correlated in the constrained condition.

Materials Research Letters, 2019

Materials Science and Engineering: A, 2019

Applied Physics Letters, 2017

This study investigates the plastic behavior of the Al0.5CoCrCuFeNi high-entropy alloy at cryogen... more This study investigates the plastic behavior of the Al0.5CoCrCuFeNi high-entropy alloy at cryogenic temperatures. The samples are uniaxially compressed at 4.2 K, 7.5 K, and 9 K. A jerky evolution of stress and stair-like fluctuation of strain are observed during plastic deformation. A scaling relationship is detected between the released elastic energy and strain-jump sizes. Furthermore, the dynamical evolution of serrations is characterized by the largest Lyapunov exponent. The largest Lyapunov exponents of the serrations at the three temperatures are all negative, which indicates that the dynamical regime is non-chaotic. This trend reflects an ordered slip process, and this ordered slip process exhibits a more disordered slip process, as the temperature decreases from 9 K to 4.2 K or 7.5 K.