Submit to Materials Review for Materials Propose a Special Issue

Journal Browser

Micromechanical Characterisation and Structures of Materials

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Advanced Materials Characterization".

Deadline for manuscript submissions: closed (20 May 2022) | Viewed by 11583

Share This Special Issue

Special Issue Editor

Dr. Alexander J. G. Lunt

E-Mail Website
Guest Editor

Materials and Structures Centre, Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK
Interests: micromechanics; synchrotron characterisation; electron microscopy; nanoindentation techniques

Special Issue Information

Dear Colleagues,

Recent decades have seen significant technological advances within the fields of microscopy, piezoelectrics and X-ray focusing optics. For example, focused ion beam systems, nanoindentation, atomic force microscopy and micro/nano-focus synchrotron beamlines have made substantial progress in terms of capabilities and are becoming increasingly available to the research community. These combined capabilities have provided access to an entirely new experimental design space within the field of mechanics, such that the quantification of mechanical properties at the micro-to-nanoscale is now becoming routinely possible. The insights gained from this type of analysis have significant implications for technique optimisation and material design. In particular, they are being used to help to understand and optimise state-of-the-art material systems and production techniques to provide increased capabilities and performance.

In this Special Issue, recent developments within the field of micromechanics and structural characterisation will be highlighted and discussed. Submissions will be welcomed across a broad range of material systems, with the central theme of high-resolution characterisation particularly focusing on technique development and novel approaches.

It is my pleasure to invite you to submit a manuscript to this Special Issue. Full papers, communications and reviews are all welcome.

Dr. Alexander J G Lunt
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Microscale characterisation
Mechanical testing
Nano/microscale materials
Technique optimization
Electron microscopy
Focused ion beam (FIB) techniques
Nanoindentation
Atomic force microscopy (AFM)
Diffraction methods

Published Papers (5 papers)

Download All Papers

Research

19 pages, 5419 KiB

Open AccessArticle

An In-Situ Electrochemical Nanoindentation (ECNI) Study on the Effect of Hydrogen on the Mechanical Properties of 316L Austenitic Stainless Steel

by Adina Basa, Dong Wang, Nuria Espallargas and Di Wan

Materials 2021, 14(21), 6426; https://doi.org/10.3390/ma14216426 - 26 Oct 2021

Cited by 3 | Viewed by 1826

Abstract

In-situ electrochemical nanoindentation (ECNI) has been used to study the effect of hydrogen on the mechanical properties of austenitic stainless steel AISI 316L. Changing the electrode potential (via electrochemical charging) revealed the interconnected nature of the hydrogen effect on the nanomechanical properties of the stainless steel. At more positive cathodic potentials, a softening effect of hydrogen can be noticed, while significant hardening can be observed at more negative cathodic potentials. The hydrogen effects on the nanomechanical properties were analyzed in terms of the homogeneous dislocation nucleation (HDN) and the hydrogen-dislocation interactions from the energy point of view. The effects can be explained with the framework of the defactant theory and the hydrogen-enhanced localized plasticity (HELP) mechanism. Full article

(This article belongs to the Special Issue Micromechanical Characterisation and Structures of Materials)

► Show Figures

Figure 1

25 pages, 9152 KiB

Open AccessArticle

Mechanical and Microstructural Characterisation of Cooling Pipes for the Compact Muon Solenoid Experiment at CERN

by George Zaburda, Antti Onnela, Kamil Cichy, Jerome Daguin and Alexander J. G. Lunt

Materials 2021, 14(12), 3190; https://doi.org/10.3390/ma14123190 - 09 Jun 2021

Viewed by 1738

Abstract

The Compact Muon Solenoid (CMS) is a particle physics experiment situated on the Large Hadron Collider (LHC) at CERN, Switzerland. The CMS upgrade (planned for 2025) involves installing a new advanced sensor system within the CMS tracker, the centre of the detector closest to the particle collisions. The increased heat load associated with these sensors has required the design of an enhanced cooling system that exploits the latent heat of 40 bar CO₂. In order to minimise interaction with the incident radiation and improve the detector performance, the cooling pipes within this system need to be thin-walled (~100 μm) and strong enough to withstand these pressures. The purpose of this paper is to analyse the microstructure and mechanical properties of thin-walled cooling pipes currently in use in existing detectors to assess their potential for the tracker upgrade. In total, 22 different pipes were examined, which were composed of CuNi, SS316L, and Ti and were coated with Ni, Cu, and Au. The samples were characterised using computer tomography for 3D structural assessment, focused ion beam ring-core milling for microscale residual stress analysis, optical profilometry for surface roughness, optical microscopy for grain size analysis, and energy dispersive X-ray spectroscopy for elemental analysis. Overall, this examination demonstrated that the Ni- and Cu-coated SS316L tubing was optimal due to a combination of low residual stress (20 MPa axial and 5 MPa hoop absolute), low coating roughness (0.4 μm Ra), minimal elemental diffusion, and a small void fraction (1.4%). This result offers a crucial starting point for the ongoing thin-walled pipe selection, development, and pipe-joining research required for the CMS tracker upgrade, as well as the widespread use of CO₂ cooling systems in general. Full article

(This article belongs to the Special Issue Micromechanical Characterisation and Structures of Materials)

► Show Figures

Figure 1

14 pages, 6363 KiB

Open AccessArticle

Characterization of Grain Size in 316L Stainless Steel Using the Attenuation of Rayleigh Wave Measured by Air-Coupled Transducer

by Meng Wang, Yangguang Bu, Zhaojie Dai and Shengyang Zeng

Materials 2021, 14(8), 1901; https://doi.org/10.3390/ma14081901 - 11 Apr 2021

Cited by 5 | Viewed by 1882

Abstract

Grain size is an important parameter in evaluating the properties of microstructures in metals. In this paper, the attenuation coefficient of Rayleigh waves is introduced to characterize grain size in heat treated 316L stainless steel. Rayleigh wave attenuation is measured using an angle beam wedge transducer as the transmitter and an air-coupled transducer as the receiver. The results show that the grain size in 316L stainless steel increases due to heat treatment time, the hardness decreases accordingly, and the attenuation coefficient of Rayleigh waves increases. This indicates that the Rayleigh wave attenuation is sufficient in distinguishing the changes in the properties of the heat-treated stainless steel. It is found that compared with the measurement method using an angle beam wedge receiver, the measured results are efficient, more stable and less influenced by the surface state when an air-coupled receiver is used. In addition, comparison results also show that the Rayleigh wave attenuation is more sensitive to changes in material properties than the longitudinal wave attenuation, as the wavelength of the Rayleigh wave is shorter than that of the longitudinal wave at the same frequency. Full article

(This article belongs to the Special Issue Micromechanical Characterisation and Structures of Materials)

► Show Figures

Figure 1

11 pages, 3355 KiB

Open AccessArticle

The Effect of a Taper Angle on Micro-Compression Testing of Mo-B-C Coatings

by Lukáš Zábranský, Katarína Bernátová, Jiří Dluhoš, Rostislav Váňa, Pavel Souček, Petr Vašina and Vilma Buršíková

Materials 2020, 13(14), 3054; https://doi.org/10.3390/ma13143054 - 08 Jul 2020

Cited by 5 | Viewed by 2439

Abstract

This research was devoted to studying the influence of the taper angle on the micro-compression of micro-pillars fabricated from near-amorphous and nanocrystalline Mo-B-C coatings. A series of micro-pillars with a taper angle between 4–14° was fabricated by focused ion beam technique. The deformation mechanism was found to be dependent on the taper and, also, on the crystallinity of the coating. In order to obtain correct values of yield strength and Young’s modulus, three empirical models of stress correction were experimentally tested, and the results were compared with nanoindentation measurements. It was shown that the average stress correction model provided comparable results with nanoindentation for the yield strength for taper angles up to ~10°. On the other hand, the average radius or area model gave the most precise results for Young’s modulus if the taper angle was <10°. Full article

(This article belongs to the Special Issue Micromechanical Characterisation and Structures of Materials)

► Show Figures

Figure 1

14 pages, 3469 KiB

Open AccessArticle

Structural and Micromechanical Properties of Nd:YAG Laser Marking Stainless Steel (AISI 304 and AISI 316)

by Piotr Dywel, Robert Szczesny, Piotr Domanowski and Lukasz Skowronski

Materials 2020, 13(9), 2168; https://doi.org/10.3390/ma13092168 - 08 May 2020

Cited by 14 | Viewed by 2807

Abstract

The purpose of this study is to examine the microstructure and micromechanical properties of pulsed-laser irradiated stainless steel. The laser marking was conducted for AISI 304 and AISI 316 stainless steel samples through a Nd:YAG (1064 nm) laser. The influence of process parameters such as the pulse repetition rate and scanning speed have been considered. The microstructures of obtained samples were analyzed using confocal optical microscopy (COM). The continuous stiffness measurements (CSM) technique was applied for nanoindentional hardness and elastic modulus determination. The phase compositions of obtained specimens were characterized by X-ray diffraction (XRD) and confirmed by Raman spectroscopy. The results revealed that surface roughness is directly related to overlapping distance and the energy provided by a single pulse. The hardness of irradiated samples changes significantly with the indentation depth. The instrumental hardness H_IT and elastic modulus E_IT drop sharply with the rise of the indentation depth. Thus, the hardness enhancement can be observed as the indentation depth varies between 100–1000 nm for all exanimated samples. The maximum values of H_IT and E_IT were evaluated for the region of small depths (100–200 nm). The XRD results reveal the presence of iron and chromium oxides due to irradiation, which indicates a surface hardening effect. Full article

(This article belongs to the Special Issue Micromechanical Characterisation and Structures of Materials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Micromechanical Characterisation and Structures of Materials

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (5 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI