Development Of Engineering Materials Research Articles

The High Temperature Strength of Single Crystal Ni‐base Superalloys – Re‐visiting Constant Strain Rate, Creep, and Thermomechanical Fatigue Testing

The present work takes a new look at the high temperature strength of single crystal (SX) Ni‐base superalloys. It compares high temperature constant strain rate (CSR) testing, creep testing, and out‐of‐phase thermomechanical fatigue (OP TMF) testing, which represent key characterization methods supporting alloy development and component design in SX material science and technology. The three types of tests are compared using the same SX alloy, working with precisely oriented <001>‐specimens and considering the same temperature range between 1023 and 1223 K, where climb controlled micro‐creep processes need to be considered. Nevertheless, the three types of tests provide different types of information. CSR testing at imposed strain rates of 3.3 × 10−4 s−1 shows a yield stress anomaly (YSA) with a YSA stress peak at a temperature of 1073 K. This increase of strength with increasing temperature is not observed during constant load creep testing at much lower deformation rates around 10−7 s−1. Creep rates show a usual behavior and increase with increasing temperatures. During OP‐TMF loading, the temperature continuously increases/decreases in the compression/tension part of the mechanical strain‐controlled cycle (±0.5%). At the temperature, where the YSA peak stress temperature is observed, no peculiarities are observed. It is shown that OP‐TMF life is sensitive to surface quality, which is not the case in creep. A smaller number of cycles to failure is observed when reducing the heating rate in the compression/heating part of the mechanical strain‐controlled OP‐TMF cycle. The results are discussed on a microstructural basis, using results from scanning and transmission electron microscopy, and in light of previous work published in the literature.

Neural rehabilitation based on brain computer interface

BCI is a newly developed technology that can be used for neurological rehabilitation of brain injuries and paralysis. This article first reviews the history of BCI, and then introduces two major neurorehabilitation BCI technologies for neurorecording and neuromodulation, invasive and non-invasive. For each technology, we describe the challenges of each technology, analyzing the current state and future development trends. In terms of non-invasive technology, the most mature and extensive EEG brain signal analysis methods and two brain regulation technologies, transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES), as well as the application of brain signal analysis techniques such as functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy fNIRS) were also discussed. In terms of invasive technology, the implantable neural interface technology focuses on implantable neural interface technology, which collects cortical electrical brain signals (ECoG), which can obtain more original neural information and has high temporal and spatial resolution characteristics. In recent years, with the development of microelectronics technology and material technology, invasive BCI technology has made a lot of cutting-edge progress, which is an important future development direction of neurorehabilitation technology.

Development of plasma technology for the preparation and modification of energy storage materials.

The development of energy storage material technologies stands as a decisive measure in optimizing the structure of clean and low-carbon energy systems. The remarkable activity inherent in plasma technology imbues it with distinct advantages in surface modification, functionalization, synthesis, and interface engineering of materials. This review systematically expounds upon the principles, classifications, and application scenarios of plasma technology, while thoroughly discussing its unique merits in the realm of modifying electrode materials, solid-state electrolytes, and conductive carbon materials, which are widely used in lithium-ion batteries, sodium ion batteries, metal air batteries and other fields. Finally, considering the existing constraints associated with lithium-ion batteries, some application prospects of plasma technology in the energy storage field are suggested. This work is of great significance for the development of clean plasma technology in the field of energy storage.

INFORMATION MODELING OF CONCRETE: CURRENT STATUS AND DEVELOPMENT PROSPECT S

The publication relates to the problems of digitalization of building materials science. The relevance of developing a digital model of concrete for solving optimization problems of design and synthesis of its structure, clarifying methods for calculating building structures, and improving the technology of their production is shown. The evolution of information modeling of concrete is analyzed in the context of the stages of development of system-building materials science and technology.
 A review of the main modern methods of computer modeling of concrete structure in domestic and foreign scientific research is provided. It is noted that these methods do not take into account the complexity of the structure of concrete. In the article, concrete is presented as a conglomerate composite with a hierarchically organized structure with dimensions from 10-10 to 10-1 m. It has a minimum of 5-6 scale levels and three types of substructure design. Substructures differ in their scale, genesis and mechanics of manifestation of properties. The first type of substructure is characteristic of the macro-, meso- and micro-scale levels. It is accepted in the form of a two-component “construction” of a spatially continuous matrix and discrete inclusions deterministically and stochastically distributed in it. The second type refers to the submicro-, ultra-micro- and nanoscale levels. It is believed to be in the form of a “microscale spatial structure” of new formations of a cementing substance from consolidated individual crystalline differences. The third type corresponds to the atomic-molecular structure of new formations of the cementing substance.
 The characteristics of each type of substructure are given according to: the scale of the components; features of formation; mechanics of properties manifestation; design criteria; means of synthesis. An assumption is made about the specificity of modeling each of the three types of concrete substructures and their integration into a single digital model. The task is to develop an information platform for such a model. The platform should include: a theoretical knowledge base; empirical data base; database of analytical, numerical and statistical models; algorithms for designing and synthesizing structures; optimization criteria and boundary conditions; terms of reference for computer modeling of concrete.

Failure analysis and evaluation for cracked concrete beam reinforced with CFRP

With the development of material technology, many kinds of fiber materials have been exploited. In all these fiber materials, carbon fiber reinforced plastic (CFRP) is widely used in civil engineering. First, in this paper the reinforcement performance and failure of cracked concrete beam reinforced with CFRP are studied by digital image correlation method. Secondly, a simple method for the evaluation of reinforcement effect for cracked concrete beam reinforced with CFRP is proposed and verified by experimental results. The reinforcement effect for cracked concrete beam reinforced with CFRP can be evaluated in the service process without specimen damage by this method. Finally, the effects of the bond defect of CFRP on reinforcement effect are studied by this evaluation method. This method plays an important role in the safe application of concrete beams reinforced with CFRP.

Modeling and simulation of multifaceted properties of X2NaIO6 (X = Ca and Sr) double perovskite oxides for advanced technological applications.

In this study, the authors have investigated the structural, optoelectronic, thermoelectric, and thermodynamic properties of Ca2NaIO6 and Sr2NaIO6 double perovskite oxides. Both materials exhibit semiconductor behavior with direct band gaps (Eg) of 0.353eV and 0.263eV, respectively. Optical parameters like absorption coefficient α(ω), reflectivity R(ω), dielectric constants, and refractive index have been calculated. The most notable absorption peaks are identified at 5.52eV (equal to 108.33 × 104cm-1) in the case of Ca2NaIO6 and at 11.16eV (equivalent to 118.17 × 104cm-1) for Sr2NaIO6. These findings suggest a promising outlook for applications in optoelectronics. Moreover, their commendably low thermal conductivity and a high figure of merit, particularly at low temperatures (100K), indicate their effectiveness as thermoelectric materials. This analysis underscores that these materials hold potential as suitable candidates for n-type doping, making them well-suited for use in thermoelectric devices. Studying thermal properties, including thermal expansion, bulk modulus, acoustic Debye temperature, entropy, and heat capacity, contributes to understanding the materials' thermodynamic stability. The titled materials are dynamically stable. The analysis of these double perovskite materials highlights their potential across various technological applications due to their advantageous structural, electronic, optical, and transport properties, offering new possibilities in material science and technology development. The study utilized the full potential linearized augmented plane wave (FP-LAPW) method in conjunction with density functional theory within the WIEN2k simulation code. This approach is widely recognized as one of the most dependable methods for evaluating the photovoltaic characteristics of semiconducting perovskites. The thermoelectric properties were ascertained using the rigid band approach and the constant scattering time approximation, both implemented in the BoltzTraP computational code.

The perspectives of diamond for 3H and 63Ni betavoltaic power sources, comparison with 4H–SiC

Recently, power sources that utilize radioisotope energy conversion, specifically the betavoltaic effect, have gained more attention due to the increasing demand for energy-efficient technologies in new electronics. These power sources are capable of delivering electrical power continuously over periods of years. Among various semiconductors, 4H–SiC and diamond are the most desirable materials for building betavoltaic structures. Although 4H–SiC betavoltaics are commercially available and have been demonstrated, diamond is still an emerging material. However, recent advancements in diamond technology, such as the demonstration of bipolar structures—a necessary requirement for high-efficiency betavoltaics—make it a promising candidate for building practical betavoltaic devices in the near future. This study aims to evaluate the potential of diamond bipolar structures for betavoltaic applications using 3H and 63Ni sources and compare the results with 4H–SiC at both room and elevated temperatures, taking into account the current level of materials technology development. The electrical parameters of these structures are estimated using the Monte Carlo transport tool GEANT4 coupled with the finite-element device simulator TCAD SILVACO. The simulation results are compared with existing experimental data for both 4H–SiC and diamond devices.

Exact solution of magneto-elastoplastic problem of functionally graded cylinder subjected to internal pressure

With the development of composite material technology, the multi-field coupling analysis of functionally graded (FG) structures has attracted extensive attention. For FG cylindrical pressure vessels, due to the non-uniform distribution of stresses filed in the structure, plastic deformation occurs irreversibly under external load, and Lorentz's force under static magnetic field is also one of the key factors affecting the elastoplastic state. Assuming that the elastic modulus of FG cylinder changes as a power function along the thickness and Poisson's ratio is constant, the hollow cylinder under the combined action of applied magnetic field and internal pressure may have four deformation states containing pure elastic deformation, partial plastic deformation yielding from the inner surface, partial plastic deformation yielding from the outer surface, and full plasticity. In this paper, analytical solutions of stress and displacement fields of the FG cylinder under these four different elastoplastic states are given, and the critical load conditions corresponding to the transition between these four different states are proposed. The correctness of the present analytical solution in this paper is verified by comparing it with the existing results of related simplified problems. In addition, the analytical solution of residual stress distribution caused by unloading internal pressure is discussed for self-reinforcing processing. Based on the analytical solution in this paper, the influence of FG parameter, applied magnetic field and internal pressure on the elastoplastic state, plastic zone size, stresses and displacements distribution of FG cylinder is analyzed in detail. This study shows that for this magneto-elastoplastic problem of FG cylinder, plastic deformation may appear from the inner surface or outer surfaces. With the increase of FG parameter, the first yielding position of FG cylinder changes from the inner surface to the outer surface. In addition, the existence of an applied magnetic field reduces the critical internal pressure required for FG cylinders to yield, making the FG hollow cylinder more prone to plastic deformation.

Simulation Study of Structural Factors Affecting the Performance of Thermal Jacket for Gun Tubes

Most of common thermal jackets for gun tubes are composite types, which have large mass and complex structures. With the development of material technology, a single-layer thermal jacket using new composite materials with low thermal conductivity has good protection effects on gun tubes. The design of a single-layer thermal jacket requires consideration of thickness, air gap, material properties and structural strength. In order to study the structural factors that affect the performance of the single-layer heat jacket, the models of various structural dimensions through a 3D modeling software were established, a thermal-mechanical coupling system was built using a finite element simulation software to simulate the different thermal jacket models. The results were compared and analyzed, and the structural factors that affect the performance of the thermal jacket were investigated.

A DNA Based Dissipation System that Synchronizes Multiple Fuels.

Artificial dissipative networks have emerged as advanced bionic systems for the development of material technology and synthetic biology. Here, we demonstrate a DNA-based artificial dissipation system that synchronizes multiple energy-rich molecules (fuels) including oligonucleotide, dNTP, and ATP. The autonomous operation of the dissipation system relies on the integration of DNA reaction network including polymerase extension, kinase phosphorylation, and exonuclease digestion. The use of multiple fuels provides multiple transient states with different energy levels and fine-tuning dissipative kinetics. The lifetime of the transient state can be programmed to increase or decrease just by varying one of the fuel molecules unlike conventional DNA-based dissipative systems where the increase in the concentration of fuel molecule increases the lifetime. This design greatly expands the toolkits for establishing dissipative/dynamic DNA networks. The dissipation system is harnessed to dynamically regulate the assembly of DNA nanotubes allowing for controlling the assembly kinetics via multiple fuels. Owing to the multiple transient states in the dissipation system, two nanotubes can be regulated in parallel. We envision that the system would find broad applications in responsive materials, soft robotics, biosensors, and on-demand drug delivery.

Application of Topological Methods in the Development of Vehicle Components

Many areas of the industry are characterized by continuous changes, which define new directions of development in product design. The development of computers and software, the spread of modern production tools and the development of material technology make it possible to expand traditional production technologies with modern processes. Integrated CAD systems have occupied their place in the product design and development process for decades, reforming classical design methods. Popular optimization procedures in integrated CAD systems, such as shape optimization, topological optimization and the new generative design process, provide effective solutions for design engineers in more and more industrial application areas. Experience shows that modern design methods can be used in many areas of industry. The appearance of metal powder printing and additive technology make it possible to test the designed prototypes or even to produce the final products. The following article aims to support the above with the help of a case study.

Refashioning repair culture through the circle of value creation: A case study of the Japanese brand KUON

During the past ten years or more, sustainable fashion and slow lifestyle has received a growing amount of attention from design scholars, creative practitioners and fashion brands. In addition to new technologies of material development, the recent incorporation of repair-inspired designs into current fashion practice is also notable. Among the origins of global repair traditions, the Japanese patchwork boro receives a shared interest from a global creative network of fashion designers, textile collectors and artisans in their exploration of sustainable materials and reinvention of ancient craftsmanship. Born from humbleness, boro signifies a class of Japanese textiles that have been extensively mended and patched together by people who could not get or afford proper clothes. The recent resurrection of boro as a style and an eco-friendly fashion statement follows the trend for sustainable design, and also benefits from the recognition of Japanese aesthetics in western fashion and design industries. By investigating the boro-influenced patchwork menswear brand KUON from Japan, this case study acknowledges and exemplifies the historical and contemporary ideological alignment of sustainable fashion with Japanese repair culture, aesthetics and material interpretations. This research considers boro as an alternative solution to the current development of new material technologies, and the discussion of boro offers future possibilities to reimagine the meanings and representations of this traditional repair craft which may inspire creative practitioners to participate and contribute to sustainable fashion design.

Effects of different joint wall lengths on in-plane compression properties of 3D braided jute/epoxy composite honeycombs

To comply with the trend in the development of engineering materials towards lightweight, high strength, eco-friendly, sustainable, and multi-functional, a three-dimensional braided integrated composite honeycomb is designed. The effects of geometrical parameters particularly joint wall lengths on the in-plane mechanical behavior of the honeycombs were investigated. The results show that the in-plane mechanical properties are related to the number of cell walls, and the angle between the cell wall and the loading direction. Increasing the number of cell rows to double and triple at similar areal density lead to an improvement of the maximum load up to 2.5, and 3.8 times, respectively. Similarly, the total absorbed strain energy increased up to 2.6 and 5.9 times, respectively. The displacement at the maximum load is increased by 1.6 and 2.7 times as a result of increasing the cell row number. The total absorbed strain energy increased to 1.7 and 1.3 times, respectively. The failure angle of the 3D braided composite honeycomb is about 4°–7°. This investigation presents the geometrical factors of a 3D braided composite honeycomb can be further designed and optimized, but it also provides a reference for the development and design of a new composite honeycomb.

Multiscale Architectured Membranes, Electrodes, and Transport Layers for Next-Generation Polymer Electrolyte Membrane Fuel Cells.

Over the past few decades, considerable advances have been achieved in polymer electrolyte membrane fuel cells (PEMFCs) based on the development of material technology. Recently, an emerging multiscale architecturing technology covering nanometer, micrometer, and millimeter scales has been regarded as an alternative strategy to overcome the hindrance to achieving high-performance and reliable PEMFCs. This review summarizes the recent progress in the key components of PEMFCs based on a novel architecture strategy. In the first section, diverse architectural methods for patterning the membrane surface with random, single-scale, and multiscale structures as well as their efficacy for improving catalyst utilization, charge transport, and water management are discussed. In the subsequent section, the electrode structures designed with 1D and 3D multiscale structures to enable low Pt usage, improve oxygen transport, and achieve high electrode durability are elucidated. Finally, recent advances in the architectured transport layer for improving mass transportation including pore gradient, perforation, and patterned wettability for gas diffusion layer and 3D structured/engineered flow fields are described.

The in situ 1 MeV Kr - irradiation study of amorphisation resistance for the Ln2TiO5 (Ln = Lanthanides and Yttrium) Series. A review

The ongoing study of ion – solid interactions is integral for the further development of advanced material technologies servicing semiconductor and nuclear materials. This review focusses on the in situ ion-irradiation, 1 MeV krypton ions, coupled with transmission electron microscopy technique used to characterise the radiation response of Ln2TiO5 (Ln = lanthanides and yttrium) series of ceramic compounds. This series consists of three distinct poly-types; orthorhombic, hexagonal and cubic symmetries, a total of 25 different compounds, allowing radiation response trends within and between structure groups to be investigated. There are three major radiation response characteristics investigated; fundamental damage cascade models, critical fluence of ions required for a crystalline to amorphous transition, and critical temperature for maintaining crystallinity.

Analisis Kekuatan Mekanik Komposit Polimer Diperkuat Serbuk Kulit Kerang

In recent decades, the development of composite material technology has continued to increase rapidly and has been used for various applications as an alternative material to replace metal. In line with growing environmental issues, the utilization of natural materials which are abundant in nature and easy to find is the main priority for composite building materials. In this study, shell powder was used as a reinforcing material for epoxy polymer composites. The aims of this study were to obtain the average compressive, tensile, and flexural strength of shell powder-reinforced polymer composite materials, to calculate the distribution of test results using the PDF method, and to calculate the contribution of shell powder to the mechanical properties mentioned using the ANOVA method. The tensile, compressive, and flexural test specimens follow the test specimen standards of ASTM D638, ASTM D7264, and ASTM D695 respectively. The composition of shell powder consists of 10%, 30%, and 50%. Testing of these mechanical properties using a UTM-type hydraulic test equipment model WEW-300D with a capacity of 300 kN. The test results show an increase in the mechanical properties of the material. The increase occurred in compressive and flexural strength where the composition was given up to 30% and 50%, namely between 120 – 125 MPa. However, increasing the composition of shell powder at 30% and 50% actually resulted in a decrease in tensile strength between 12 – 9 MPa. Finally, based on the results of ANOVA analysis, it was shown that the addition of shell powder as a reinforcement for polymer composites significantly improved their mechanical properties.

Current Status and Development Tendency of Wearable Cardiac Health Monitoring

Wearable cardiac monitoring devices can provide uninterrupted monitoring of cardiac activities over a long period of time. They have developed rapidly in recent years in terms of convenience, comfort, and intelligence. Aided by the development of sensor and materials technology, big data and artificial intelligence, wearable cardiac monitoring can become a crucial basis for novel medical models in the future. Herein, the basic concepts and representative devices of wearable cardiac monitoring are first introduced. Subsequently, its core technologies and the latest representative research progress in physiology signal sensing, signal quality enhancement, and signal reliability are systematically reviewed. Finally, an insight and outlook on the future development trends and challenges of wearable cardiac monitoring are discussed.

Theoretical connection from the dielectric constant of films to the capacitance of capacitors under high temperature

AbstractIn the process of coping with energy and environmental protection issues, technologies such as energy materials, energy devices, and energy systems have made great progress. With excellent performance, film capacitors play an increasingly important role in energy‐related fields. With the increase of application scenarios and the continuous development of film material technology, it is urgent to establish a better theoretical connection from films to capacitors. First, the main components of the capacitor including the film and the positional relationships among them are given. Then, from the two perspectives of indirect calculation according to the volume and the direct calculation according to the winding process, the equation between the dielectric constant of films and the corresponding capacitance of capacitors is established. Further, the measurement data and error analysis results of the built test platform prove the accuracy and great potential of the proposed calculation methods. In addition, error sources, including film thickness uniformity, are listed. Finally, the challenges faced by the proposed calculation methods and the paths that can be referenced for future research are summarised and discussed.

Research Progress of Resonance Optical Fiber Sensors Modified by Low‐Dimensional Materials

AbstractResonance optical fiber sensors are widely studied for their high sensitivity, small size, and anti‐electromagnetic interference. However, traditional resonance optical fiber sensors have encountered bottlenecks in the trace detection due to limited localized field intensity and low molecules affinity. With the development of materials technology, low‐dimensional materials such as quantum dots, graphene, and transition metal sulfides have excellent properties such as high carrier mobility, large specific surface area, and flexible structure controllable artificial technologies that can also be used to synthesize new materials with desired characteristics, which can enhance the performance of sensors fundamentally. The introduction of low‐dimensional materials can not only achieve the performance optimization of sensors, but also make sensors functional to realize the diversification of detection objects. This paper reviews the research progress of resonance optical fiber sensors based on low‐dimensional materials. The detection principle and performance indexes related to resonance optical fiber sensing are elaborated, and resonance optical fiber sensors modified by low‐dimensional materials are introduced. Furthermore, the role of low‐dimensional materials in resonance fiber sensing is summarized, the direction of performance optimization in the production process of resonance fiber sensors is analyzed, and the future prospect of new resonance optical fiber sensors is given.

Empirical research on the friction behavior of O-rings in hydraulic cylinders.

Mechanical products are becoming more diversified with the continuous development of precision processing and materials technologies. The friction force generated by the O-ring seal in a hydraulic cylinder was once considered redundant. However, its utilization has recently been proposed. The hardness of the O-ring and the inner diameter of its groove directly affect the normal pressure between the O-ring and the inner wall of the cylinder, thereby affecting the friction behavior. In order to explore this friction behavior, a strain-based friction force measurement system is developed in this study, and the steady-state and dynamic friction values under different working conditions are studied and discussed in depth. This research on the friction behavior in the cylinder provides a theoretical basis for more convenient design and utilization of the friction force generated between the O-ring and the inner wall of the cylinder.