Super-strong Materials Research Articles

An Overview of Mechanical Properties of Diamond-like Phases under Tension.

Diamond-like phases are materials with crystal lattices very similar to diamond. Recent results suggest that diamond-like phases are superhard and superstrong materials that can be used for tribological applications or as protective coatings. In this work, 14 stable diamond-like phases based on fullerenes, carbon nanotubes, and graphene layers are studied via molecular dynamics simulation. The compliance constants, Young's modulus, and Poisson's ratio were calculated. Deformation behavior under tension is analyzed based on two deformation modes-bond rotation and bond elongation. The results show that some of the considered phases possess very high Young's modulus (E≥1) TPa, even higher than that of diamond. Both Young's modulus and Poisson's ratio exhibit mechanical anisotropy. Half of the studied phases are partial auxetics possessing negative Poisson's ratio with a minimum value of -0.8. The obtained critical values of applied tensile strain confirmed that diamond-like phases are high-strength structures with a promising application prospect. Interestingly, the critical limit is not a fracture but a phase transformation to the short-ordered crystal lattice. Overall, our results suggest that diamond-like phases have extraordinary mechanical properties, making them good materials for protective coatings.

Temperature- and internal structural size-dependent strength of nanotwinned face-centered cubic metals

The Nanotwin structure exhibits great potential as a strengthening medium, with its effectiveness influenced by both internal structural size and temperature. In this work, we developed a strength model that incorporates the dependence on temperature and internal structural size. This model can predict the strength of nanotwinned (NT) FCC metals with intracrystalline or intercrystalline twin boundaries featuring different internal structural sizes at varying temperatures at the inverse Hall-Petch stage. The proposed prediction model has significant importance for enhancing our understanding of the mechanical behavior exhibited by NT metals and facilitating the design of super-strong materials that can withstand extreme conditions.

Influence of Structural Parameters - the Shape of Graphite and Matrix on Change of Ultrasonic Wave Propagation Rate and Value of Attenuation in Graphitic Cast Irons

Abstract Despite the tendency of the current industry, especially the automotive industry, it is to use modern, light and super-strong materials based on Al or HSLA steels, the application of classic materials such as cast iron still makes sense, especially concerning price and excellent castability. The article presents one of the possible ways of using the ultrasonic non-destructive method in quality control and simplification of the identification of the type of cast iron concerning the change of parameters of ultrasound propagation in materials. The main criteria for assessing the quality and determining the type of graphite cast iron were considered to be the rate of propagation of ultrasound - cL and the value of attenuation - α, which vary depending on the shape of the graphite and matrix. Graphitic cast irons with different graphite shapes (lamellar, vermicular, and globular shapes) and a matrix with different ferrite/perlite ratios were used as experimental material. Along with the ultrasonic tests, a metallographic analysis was also performed to quantify the microstructure of cast irons.

The polymer nanocomposite characteristics on various mixtures and mixing times in simple mixing method

Science and technological developments in the material field have been currently dedicated to a super strong material potential based on nanotechnology. The super strong material can be created from the mixture of epoxy-resin polymer and SiO2 (silicon dioxide) nanoparticles. Polymers exist as a nanoparticle adhesive due to nano-SiO2, which possesses a high amorphic level, resulting in a stronger, more flexible, and stiffer combination than the current super strong material. The advantages of nanocomposite polymer using epoxy- resin and nano-SiO2 produce strong and light products with an easier production process, utilizing local materials that can improve the following material quality. This study used four material variations, namely P30, P35, P40, and P45, combined with nanoparticles at 0%, 1%, 2%, 3%, and 4%. Based on the results, the highest compressive strength level was found on the PNK 40 EH2:1N1 mixture at 53.18 MPa with 1627 kg/m3 weight density. From the X-Ray Diffraction (XRD) test results, the following mixture had the lowest amorphic phase, while Fourier Transform Infra-Red (FTIR) test results showed that the following mixture absorbed more hydrogen elements, and Scanning Electron Microscope (SEM) observation on the following material mixture had more organized particle distribution.

Preparation of super-strong ZrO2 ceramics using dynamic hot forging

In this study, dynamic hot forging (DHF) was proposed and applied to make super-strong zirconia (ZrO2) ceramics. The flexural strength of the sample forged at 1400 ℃ reached 1860 MPa, which was more than 3 times higher than that of the unforged commercial zirconia ceramics and 120 MPa higher than the conventional hot forged zirconia ceramics. The microstructural analysis suggested that the anomalously high strength is due to grain boundary strengthening caused by grain boundary sliding and grain strengthening caused by work hardening. It is anticipated that DHF could be applicable to other material systems to make super-strong materials.

Super-strong materials: Fueling sustainable hydrogen transportation

Super-strong materials: Fueling sustainable hydrogen transportation

Oxygen-terminated M4X3 MXenes with superior mechanical strength

Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, have gained notable attention recently because these super-strong materials have many promising applications. In this study, computational analysis is conducted to explore the in-plane elastic constants, 2D stiffness and shear modulus of oxygen terminated M4X3 MXenes by means of the density functional theory (DFT) calculations. Our results reveal that the binding site of the oxygen atoms can greatly affect the mechanical properties. The crystal orbital Hamilton population (COHP) analysis suggests that the impact of the oxygen-binding site is because the M − O bonding strength can significantly influence their mechanical stiffness. Our outcomes may, therefore, provide the theoretical foundation for the advance of MXene-based applications in mechanical engineering.

Toughening a superstrong carbon crystal: Sequential bond-breaking mechanisms

A complex orthorhombic carbon allotrope in $Pbam$ symmetry with 32 atoms in its unit cell, thus termed $Pbam$-32 carbon, was recently predicted [C. Y. He et al., Phys. Rev. Lett. 121, 175701 (2018)]. Its crystal structure comprises alternating fivefold, sixfold, and sevenfold carbon rings and exhibits reduced bonding anisotropy compared to diamond, raising the prospects of finding a superstrong material with distinct and favorable mechanical properties. Here we report findings from first-principles calculations that reveal peculiar stress-strain relations in $Pbam$-32 carbon. The obtained stress responses under various tensile and shear strains display outstanding characteristics contrasting those of traditional superhard materials like diamond and cubic boron nitride ($c$-BN). The $Pbam$-32 carbon undergoes structural deformations that produce highly isotropic stress responses under a wide variety of large tensile and shear strains, showcasing unprecedented nearly degenerate stress-strain curves along multiple deformation paths extended over ultralarge, including full-range, strains up to the bond-breaking points. These deformation modes impede or even suppress the graphitization process commonly seen in highly strained diamond and $c$-BN crystals while still sustaining large peak stresses comparable to those in diamond. Most notably, we find conspicuous bond-weakening and -breaking mechanisms stemming from bonding symmetry reduction in $Pbam$-32 carbon. At large tensile strains, a sequential bond elongation process occurs, generating a more ductile deformation past the peak stress; at large shear strains, the crystal structure goes through a similar sequential bond elongation process and, interestingly, transforms into a distinct three-dimensional network containing mixed $s{p}^{2}$ and $s{p}^{3}$ bonding states, suppressing the usual graphitization process. These more gradual bonding-state changes in the severely strained $Pbam$-32 carbon improve ductility and toughness in this superstrong carbon crystal. These insights elucidate mechanisms for toughening superstrong covalent crystals via microstructural arrangements, which shed light on rational design and development of a distinct class of superstrong materials that exhibit more isotropic mechanical responses with improved toughness under diverse loading conditions.

The Great Reduction of a Carbon Nanotube’s Mechanical Performance by a Few Topological Defects

It is widely believed that carbon nanotubes (CNTs) can be employed to produce superstrong materials with tensile strengths of up to 50 GPa. Numerous efforts have, however, led to CNT fibers with maximum strengths of only a few GPa. Here we report that, due to different mechanical responses to the tensile loading of disclination topological defects in the CNT walls, a few of these topological defects are able to greatly decrease the strength of the CNTs, by up to an order of magnitude. This study reveals that even nearly perfect CNTs cannot be used to build exceptionally strong materials, and therefore synthesizing flawless CNTs is essential for utilizing the ideal strength of CNTs.

Using Approximate Bayesian Computation to Assess the Reliability of Nanocomponents of a Nanosystem

Nanosystems have great potential in practical applications such as: sensors, circuits, solar panels, super strong materials, protective coatings, and drug delivery. Much research is devoted to designing and fabricating these nanosystems. However, the question of reliability is often overlooked during the design process. Specifically, the ability to analyze the reliability of the nanocomponents is lost. In this paper, we introduce the use of Approximate Bayesian Computation to assess nanocomponent reliability. Data on the lifetime of the nanocomponents is not required with this approach; instead data on the lifetime of the nanosystem is utilized. The proposed statistical and computational algorithms result in a more comprehensible understanding of the nanosystem in order to improve the overall reliability.

Beyond graphene

These are the halcyon days of research on graphene, a much heralded superstrong material. Since atom-thin sheets of carbon were first isolated in 2004, thousands of researchers have leapt at the chance to get to know this exotic material better and figure out what to do with it. Not only is graphene robust and relatively easy to prepare in the laboratory, it also boasts an astonishing portfolio of useful properties. Electrons can zip through graphene many times faster than they do through silicon. Graphene is stronger than steel, and can absorb light at any wavelength. Last year, researchers published nearly 18,000 papers on graphene, according to the Thomson Reuters Web of Science database. Although graphene transistors are still in the experimental stage, the material is already starting to appear in commercial applications, from strengthening carbon composite materials to enhancing touchscreens in smartphones.

Loaded sectioned space elevator

New super strong materials discovered at the end of the 20th century have caused a surge of activity in work devoted to the space elevator (SE). A rather complete concept of the SE has been formulated. This concept, having many advantages, possesses, nevertheless, limited capabilities and insufficient reliability. In this paper we present a modified space elevator concept [1] that has higher reliability and extended capabilities. Such a construction is more complicated and its design is more expensive, so it can be realized only as a part of a large-scale space program. Inclusion of a space elevator in such a program will facilitate development of new technologies.

Nano-Science and Nano-metrology for Societal Benefits

In general nanotechnology can be described as the manipulation of matter with at least one dimension in the range of 1–100 nm. It refers to a very broad range of research and applications whose common trait is size. It includes fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, quantum physics, etc. The applications of nanotechnology are equally broad, ranging from devices for ICT to completely new concepts of molecular self-assembly, from intelligent coatings to super-strong materials with designed properties, and of course microfabrication. The concept of nanotechnology was probably first discussed by Richard Feynman in his famous talk ‘‘There is plenty of room at the bottom’’, in which he described the possibility of synthesis (assembling) via direct manipulation of atoms. There have also been a number of Nobel Prizes in this field. The first one, in 1986, was for the invention of the scanning tunnelling microscope in 1981 by Binning and Rohrer at IBM. This invention kick-started the whole field of scanning probe microscopy which enabled the study of physics at the atomic scale. In 1996 Kroto and Smalley received the Nobel Prize for their discovery of the molecule C60-fullerene (a perfect sphere of 60 carbon atoms) in 1985. As recently as 2010, Geim and Novoselov from the University of Manchester received the Nobel Prize for their 2004 discovery of graphene, a single atomic layer isolated from graphite. In particular graphene has sparked an unparalleled burst of scientific activity across the globe with the number of scientific publications exceeding 40,000. The present and future societal impact of nanotechnology is also huge. Nanotechnology can be found in thousands of products already publicly available, from sunscreens and cosmetics to food packaging and surface coatings. Also the electronics industry is awash with nanocomponents. The transistor gate length in the latest computer chips is as small as 10 nm and in these devices quantum effects such as tunnelling start to dominate the performance. Maybe more interesting are the future applications of nanotechnology such as the development of personalised healthcare, and energy generation and storage which have the potential to dramatically change our society. Quite possibly the biggest applications are the ones we haven’t even thought of yet. Realising this potential brings us to the need for metrology to underpin this technology. Metrology has a crucial role in order to produce nanomaterials and devices with a high degree of accuracy and reliability in nanomanufacturing. The central challenge in nanometrology is to develop new measurement techniques, reference samples and standards which meet the future requirements of industry. Already, the need for measurement and characterisation of some new devices exceeds the current capabilities of metrology laboratories and will become even more pressing in the near future. The metrology community needs to respond to this and continue to drive down the minimum length scale in measurement science. This activity will require fundamental research which often will involve collaborations with academia as well as close collaboration with end-users of nanotechnology that are responsible for product development and manufacturing. Because the functioning of nanotechnology devices critically relies on dimensions and surface dependant properties, metrology will form an essential component in the fabrication process and the challenge is to achieve such high-end measurements away from the metrology laboratory on the factory floor. In this special issue of MAPAN we have aimed to cover several aspects from this wide spectrum of nano-science and nano-metrology that includes quantum metrology, surface and nanoanalysis, nanofabrication, solar cell and standardisation of nanotechnologies. We hope this special issue will bring an insight into the needs for metrology and *Corresponding author, E-mail: debdulal.roy@npl.co.uk M APAN-Journal of Metrology Society of India (December 2013) 28(4):237–238 DOI 10.1007/s12647-013-0093-6

The effect of nanostructural hierarchy on the mechanical properties of aluminium alloys during deformation processes

New generation of lightweight structures and technologies enables the development of materials to exhibit superior property combinations. In the present work, cellular automata is used to address the problem of dislocation behaviour and 4 factors: (i) a high density of dislocations, (ii) sub-nanometre intragranular solute clusters, (iii) 2 geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter featuring in aluminium alloys containing a nanostructural hierarchy and exhibiting record strength with good ductility—an aerospace grade 7075 alloy exhibits a yield strength of 1 GPa and total elongation to failure of 9 %. We show that the clusters and geometries of nanometre-scale intergranular solute structures govern the strength of such material, resulting in their increasing elongation. Our results demonstrate that this simulation explains the phenomena of the super-strong materials of new generation with entirely new regimes of property-performance space.

Nanostructural hierarchy increases the strength of aluminium alloys

Increasing the strength of metallic alloys while maintaining formability is an interesting challenge for enabling new generations of lightweight structures and technologies. In this paper, we engineer aluminium alloys to contain a hierarchy of nanostructures and possess mechanical properties that expand known performance boundaries-an aerospace-grade 7075 alloy exhibits a yield strength and uniform elongation approaching 1 GPa and 5%, respectively. The nanostructural architecture was observed using novel high-resolution microscopy techniques and comprises a solid solution, free of precipitation, featuring (i) a high density of dislocations, (ii) subnanometre intragranular solute clusters, (iii) two geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of super-strong materials with new regimes of property-performance space.

The Beat

The Beat

Nanotubes and the Pursuit of Applications

AbstractA wide range of potential applications was suggested shortly after carbon nanotubes were discovered, including new super-strong materials, field-emission devices, hydrogen storage systems, novel electronic devices, and more. In this article, the actual advances in the technology of nanotubes over the last decade are examined. Particular attention is focused on current commercially viable applications and those with imminent commercial promise. The relatively large number of nanotube-related patents and nanotube-based startup companies stand in contrast to the relatively low output in commercial applications. The drive toward nanotube applications, in contrast to nanotube science, is investigated.

Tubes of pure carbon could be the key to super-strong materials

Tubes of pure carbon could be the key to super-strong materials