Researchers at Kanazawa University discover how to make pearlite stretch or contract more by changing the distance between irregularities in atomic arrangements along its nanolayer boundaries
Pearlitic steel, or pearlite, is one of the strongest materials in the world and can be made into thin and long wires. The strength of pearlite allows it to sustain very heavy weight, however what makes it special is its ability to stretch and contract without breaking (ductility).
Interfacial-dislocation-controlled deformation and fracture in nanolayered composites. The spacing of the interfacial dislocations, which accommodate misfit strain between the ferrite and cementite phases, determines the phase stress and the interfacial dislocation network in the nanolayered-pearlite models. Various modes of initially activated inelastic-deformation are observed according to interfacial dislocation spacing because the phase stress and the interfacial dislocation network influence the resolved shear/normal stress and the critical resolved shear/normal stress for each inelastic-deformation mode, respectively. Hence, interfacial dislocation spacings can be a key parameter that controls the ductility of drawn pearlitic steels and leads us toward higher ductility of drawn pearlitic steels.
Credit: Kanazawa University
Usage Restrictions: The image may only be used with appropriate caption and credit.
Ductility is important for building bridges, as even if a material is strong enough to support heavy weight, it can break when subjected to stretching if it is not ductile enough.
This is why structures made of concrete can still collapse during violent earthquakes. Pearlite is used for suspension bridges to help them withstand strong shaking while supporting heavy weight.
Pearlite is made of alternating nanolayers of cementite and ferrite. The cementite helps make it strong, while the ferrite helps make it ductile. However, until now researchers did not know exactly how the two worked together to give pearlite its special quality, or better yet, how to control their working together to engineer an even better material.
Researchers at Kanazawa University have discovered that disruptions, or dislocations, in the arrangement of atoms along the interface between a cementite and a ferrite layer protect the cementite from fracturing under stretching or compression. Their study was published last month in the journal Acta Materialia.
"The spacing between dislocations on a cementite-ferrite interface determines how deformation travels through the nanolayers", the authors say. "Manipulating the dislocation structure and the distance between dislocations can control the ductility of pearlite."
The researchers used computer simulations to see how a pearlite wire would deform with dislocations of different orientations and different distances between them along the ferrite-cementite interface. They found that particular dislocation structures and distances could stop cracks from forming or spreading throughout the cementite layer.
"Increasing the ductility of pearlite means it can resist more shearing stress without breaking or tearing," say the authors. This may lead to a new generation of materials for constructing buildings and bridges that can withstand stronger earthquakes.
The researchers believe manipulating dislocations consisting of entire clusters of atoms could be a general technique for enhancing not only ductility but other properties of materials to meet particular engineering and construction needs.
Tomoya Sato | EurekAlert!
When Concrete learns to pre-stress itself
15.07.2020 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
TU Graz researchers want to fundamentally improve concrete diagnostics
29.06.2020 | Technische Universität Graz
Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.
Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...
An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.
Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...
Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...
“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.
Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...
An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.
Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...
23.07.2020 | Event News
21.07.2020 | Event News
07.07.2020 | Event News
06.08.2020 | Earth Sciences
06.08.2020 | Power and Electrical Engineering
06.08.2020 | Life Sciences