The 50 most-cited articles in Journal of Materials Science, 2022

Abstract Laser powder bed fusion (LPBF) is an emerging additive manufacturing technique that is currently adopted by a number of industries for its ability to directly fabricate complex near-net-shaped components with minimal material wastage. Two major limitations of LPBF, however, are that the process inherently produces components containing some amount of porosity and that fabricated components tend to suffer from poor repeatability. While recent advances have allowed the porosity level to be reduced to a minimum, consistent porosity-free fabrication remains elusive. Therefore, it is important to understand how porosity affects mechanical properties in alloys fabricated this way in order to inform the safe design and application of components. To this aim, this article will review recent literature on the effects of porosity on tensile properties, fatigue life, impact and fracture toughness, creep response, and wear behavior. As the number of alloys that can be fabricated by this technology continues to grow, this overview will mainly focus on four alloys that are commonly…

Abstract This review paper provides a recent overview of current international research that is being conducted into the functional properties of cellulose as a nanomaterial. A particular emphasis is placed on fundamental and applied research that is being undertaken to generate applications, which are now becoming a real prospect given the developments in the field over the last 20 years. A short introduction covers the context of the work, and definitions of the different forms of cellulose nanomaterials (CNMs) that are most widely studied. We also address the terminology used for CNMs, suggesting a standard way to classify these materials. The reviews are separated out into theme areas, namely healthcare, water purification, biocomposites, and energy. Each section contains a short review of the field within the theme and summarizes recent work being undertaken by the groups represented. Topics that are covered include cellulose nanocrystals for directed growth of tissues, bacterial cellulose in healthcare, nanocellulose for drug delivery, nanocellulose for water purification,…

In 2004, Geim and Novoselov discovered two-dimensional graphene comprised of sp2 carbon atoms. Graphene is a thin layer of carbon consisting of excellent surface area, thermal conductivity, high electron mobility, greater mechanical strength, high electrical conductivity, and current density. Graphene attained significant attention among the research community. The properties and attributes of graphene make this material sufficiently promising to be utilized in different sectors. Based on this, researchers' interest in exploring innovative methods to develop quality graphene for the industrial purpose have increased. Therefore, this review presents a current research development on the synthesis methods of graphene and its composites and their structure and properties. Furthermore, the practical aspects of graphene and its derivatives that are fabricated via these techniques for different graphene-based applications in the development of biosensors, water treatment, solar energy systems, fuel cells, catalysis engineering, food package engineering, and various other applications are…

Abstract Metal additive manufacturing (AM) has unlocked unique opportunities for making complex Ni-based superalloy parts with reduced material waste, development costs, and production lead times. Considering the available AM methods, powder bed fusion (PBF) processes, using either laser or electron beams as high energy sources, have the potential to print complex geometries with a high level of microstructural control. PBF is highly suited for the development of next generation components for the defense, aerospace, and automotive industries. A better understanding of the as-built microstructure evolution during PBF of Ni-based superalloys is important to both industry and academia because of its impacts on mechanical, corrosion, and other technological properties, and, because it determines post-processing heat treatment requirements. The primary focus of this review is to outline the individual phase formations and morphologies in Ni-based superalloys, and their correlation to PBF printing parameters. Given the hierarchal nature of the microstructures formed during PBF, detailed…

Abstract Alloys processed by laser powder-bed fusion show distinct microstructures composed of dislocation cells, dispersed nanoparticles, and columnar grains. Upon post-build annealing, such alloys show sluggish recrystallization kinetics compared to the conventionally processed counterpart. To understand this behavior, AISI 316L stainless steel samples were constructed using the island scan strategy. Rhodonite-like (MnSiO3) nanoparticles and dislocation cells are found within weakly-textured grains in the as-built condition. Upon isothermal annealing at 1150 °C (up to 2880 min), the nucleation of recrystallization occurs along the center of the melt pool, where nuclei sites, high stored elastic energy, and local large misorientation are found in the as-built condition. The low value of the Avrami coefficient (n = 1.16) can be explained based on the non-random distribution of nucleation sites. The local interaction of the recrystallization front with nanoparticles speeds up their coarsening causing the decrease of the Zener-Smith pinning force. This allows the progression of…

Abstract In this current paper, we report the use of inexpensive, simple electrophoretic deposition (EPD) technique in developing polyaniline (PANI) aqueous colloidal suspension coating on copper (Cu) substrate. Polyaniline nanoparticle films were deposited electrophoretically on the surface of copper sheet electrode. A colloidal suspension with high stability was produced by a liquid polyaniline in the presence of formic acid and acetonitrile as electrolyte for the EPD process. The suspension of the PANI was characterized by measuring the zeta potential of the suspension using zeta-sizer analyser. The PANI coating was used as barrier for corrosion protection of the Cu sheet. Operating parameters such as operating time, applied voltage, and the concentration were used with deposition at the cathode. Characterization such as XRD, SEM, FT-IR, and UV–Vis was carried out, and the corrosion protection offered by the PANI on the Cu surface was examined using potentiodynamic (Tafel) polarization in 3.5% NaCl solution at room temperature. As a result, the optimum parameters for obtaining a…

Abstract Organic light-emitting devices (OLEDs) have garnered significant research attention owing to their immense application prospects in leading technologies for full-color flat panel displays and eco-friendly solid-state lighting. They demonstrate exceptional features such as mercury-free construction, wide viewing angle, superior color quality and captivating flexibility. The requirements of light-emitting organic materials pertaining to high stability, lifetime and luminescence quantum yield, combined with the fabrication of devices with high performance efficiency, are highly challenging. Rational molecular design of 1,8-naphthalimide (NI) derivatives can offer quite promising results in achieving standard-light-emitting materials with a wide range of colors for OLED applications. This review is mainly focused on the synthesis and usage of varyingly substituted NI frameworks as luminescent host, dopant, hole-blocking and electron-transporting materials for OLEDs that emit not only red, orange, green and blue colors, but also function as white emitters, which can really have…

Abstract Nowadays, Li–S batteries are considered as one of the most promising alternatives to Li-ion technology in the near future, thanks to their high specific capacity and their significantly lower environmental impact and production costs. Consequently, many efforts have been directed to tackle with the inherent issues that affect Li–S batteries. One of the main problems is the so-called shuttle effect, which basically entails the unwanted migration of lithium polysulfides (LiPSs) from the cathode to the anode side, causing the degradation of the cell. Here, we report an effective strategy to restrain the shuttle effect and increase the kinetics at the cathode of the lithium–sulfur (Li–S) battery. A functional layer including high entropy oxides (HEO) coated onto the sulfur cathode allows to exploit the HEOs capability as promoter catalysts for the conversion of LiPSs. Pure HEO powders are synthesized by fast, highly efficient microwave irradiation, followed by heat treatment at 930 °C. The formation of highly crystalline HEO is confirmed by X-ray diffraction analysis. The LiPSs…

Flexible and stretchable strain sensors are in great demand in advanced health care, human–machine interface, stretchable electronics, electronic skin, etc. Of the various strain sensing mechanisms, the piezoresistive technique has many advantages over other methods such as capacitive, piezoelectric, and optical sensing techniques. A typical flexible/stretchable resistive sensor is realized using an insulating polymer substrate with conducting filler materials. Intrinsically conducting polymers (ICPs) such as polypyrrole (PPy), polyaniline (PANI), and poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS) are used as primary or secondary filler in the polymeric or fibrous substrates to fabricate stretchable composite sensors. This review comprehensively discusses the development of flexible and stretchable strain sensors using conducting polymers. The material combinations, fabrication methods, quantitative metrics such as maximum sensitivity, stretchability, durability, and salient features of various stretchable resistive strain sensors are summarized, which would…

Abstract One of the major challenges in off-shore tidal and wave energy devices is the ageing of these structures in the hostile marine environment, which limits their operating life. In this research, mechanical properties of aged glass/epoxy and carbon/epoxy composite specimens including tensile strength, Young’s modulus, flexural strength, and shear strength, following immersion in a representative accelerated marine degradation environment (artificial seawater, with 3.5% salinity at room temperature and 60 °C) have been investigated. The microstructure and physicochemical characterization of the aged samples were assessed via microscopic imaging, micro-CT scanning and differential scanning calorimetry. The degradation phenomenon was apparent in the change of mechanical properties and microstructure of composite laminates (micro-cracks and debonding between matrix and fibre). Generally, the ageing process had a more severe effect on tensile and shear strengths of glass/epoxy samples than those of carbon/epoxy specimens. Reversely, the results of bending tests of carbon/epoxy…

Abstract Transparent conductive oxides (TCOs) constitute a class of materials that combine high electrical conductivity and optical transparency. These features led to the development of the transparent electronics applications, such as flat panel displays, “smart” windows or functional glasses. N -type TCOs dominate the applications market, and the lack of a suitable p-type counterpart limits the fabrication of a completely transparent active device, which might be considered as a technological breakthrough. Among the wide range of p-type candidates, delafossite CuCrO 2 (and its out-of-stoichiometry derivatives) is a promising material to achieve the desired p-type TCO properties as, up to date, it is presenting the foremost trade-off between optical and electrical properties. The present paper covers the research work and the major achievements related to copper chromium delafossite. A comprehensive overview of fabrication methods and opto-electronic properties is presented. The source of doping and the charge carriers transport mechanism are also thoroughly discussed. Graphical…

Abstract Laser powder bed fusion (L-PBF), categorized as additive manufacturing technique, has a capability to fabricate NiTi (Nitinol) shape memory alloys with tailorable functional properties and complex geometries. An important processing parameter, hatch distance (h), is often related to macroscale structural defects; however, its role on controlling the microstructure and functional properties is usually underestimated in L-PBF of NiTi. In this work, equiatomic NiTi (50.0 at% Ni) parts were fabricated with various hatch distances to tailor the microstructure and their shape memory characteristics. Contrary to what is observed in Ni-rich NiTi alloys, in this work, we demonstrate that phase transformation temperatures of L-PBF equiatomic NiTi do not decrease proportionally with hatch distance but rather relate to a critical hatch distance value. This critical value (120 μm) is derived from the synergistic effect of thermal stress and in situ reheating. Below this value, epitaxial grain growth and in situ recrystallization are enhanced, while above, irregular grains are formed and…

Abstract An innovative cost-effective and lead-free polymer nanocomposite of polyvinyl alcohol/ polyvinyl pyrrolidone was developed. PVA/PVP nanocomposite film contained spherical AgCl and SnO 2 nanoparticles was facilely prepared via a one-pot synthesis method. The synthesis route affords uniform dispersion of the both nanoparticles and unique features of polymer nanocomposite of insoluble, dense, and nonporous properties. The new nanocomposite achieved an efficient gamma radiation attenuation capability. The attenuation capacity for gamma photons was investigated in terms of linear and mass attenuation coefficients (µ) and (µ m ), respectively, at low and high energies (using 60 Co and 137 Cs sources). Other parameters such as half value layer (HVL), tenth value layer (TVL), and mean free path (MFP) were used to evaluate the shielding capacity. Theoretical calculation (XCOM program) results were consistent with the obtained experimental results. The results revealed that the essential thickness of the polymer nanocomposite to reduce the γ-ray intensity to 50% is 6.6, 8.9, and 9.8…

Abstract Timber cladding has been used since historical times as a locally available, affordable weather protection option. Nowadays, interest in timber cladding is again increasing because of ecological reasons as well as naturalistic viewpoints. This review presents a comprehensive report on timber cladding in a European context, beginning with a brief overview of the history before considering contemporary use of timber cladding for building envelopes. The basic principles of good design are considered, paying attention to timber orientation, fixings and environmental risk factors. The relationship of timber with moisture is discussed with respect to sorption behaviour, dimensional instability and design methods to minimise the negative consequences associated with wetting. The behaviour of timber cladding in fires, the effects of environmental stresses and weathering, as well as the cladding properties and the variation thereof with different types of wood and anatomical factors (including exposure of different timber faces), are examined. The review then moves on to considering…

Natural fiber-reinforced polymer composites (NFRPCs) are being widely used in aerospace, marine, automotive and healthcare applications due to their sustainability, low cost and ecofriendly nature. The NFRPCs manufactured through conventional and computer-controlled intelligent manufacturing techniques may contain internal and external defects. Traditionally, the microstructure of NFRPCs at different stages of manufacturing was obtained using destructive techniques which have stringent sample size restrictions and may cause a decrease in residual properties of composites due to destructive scanning. However, these complications can be overcome by using non-destructive evaluation (NDE) and artificial intelligence (AI) techniques. This review highlights the impact of NDE and AI on the improvement of emerging manufacturing systems. We have discussed the classification of biocomposites, their manufacturing techniques, recyclability and strategies to improve mechanical properties. Further, the use of different types of contact and non-contact NDE techniques in understanding the…