Showing papers in "Solid State Phenomena in 2022"

Assessment of Shear Bond Strength of Thermal Spray Coatings by Applying Prismatic Samples

Abstract: The purpose of this study was the research for a non-standardized method of measuring the shear bond strength at constant compression force and compare with the shear testing methods on cylindrical and prismatic samples, like DIN 50161:1977-10, DIN EN15340-2007. The conducted comparative analysis showed a significant shortcoming of the well-known methods for assessing the shear bond strength on samples for industrial application. The main one is an inability to measure the “actual/real” adhesion shear strength of thermal spray coatings for industrial parts. The shear bond strength of plasma-sprayed coating MgAl2O4 with thickness 0.30-has been investigated by applying the prismatic samples (linear dimensions of shear area 1.5-), using Nanovea scratch tester at compression forces ranging from 1 to 70 N. Shear force-displacement curves get essential information about adhesion/cohesion, delamination and cracking properties of thermal spray coating. An increase of shear forces is primarily associated with a rise in friction forces at the coating delamination boundary. Applying for parts of the ITER blanket modules, this research has demonstrated the importance of practical application of the shear testing results at compressive loads for ensuring product life.

Heat-Resistant Al-Alloys with Quasicrystalline and L1₂- Precipitates

Abstract: We have been developing Al-Mn-Cu based alloys alloyed with minor additions of different elements. Small additions of beryllium enhance the formation of the icosahedral quasicrystalline phase (IQC) during solidification, especially during ageing. Upon solidification, primary IQC-particles may form, with sizes, ranging from 5 to 50 μm. IQC is also present as a part of binary eutectic in the interdendritic regions. More importantly, nanosized quasicrystalline precipitates can form during T5-treatment at temperatures ranging from about 250−450 °C. They are, in fact, metastable precipitates transforming to ternary T-precipitates (Al 20 Mn 3 Cu 2 ) phase above 450 °C. The heat resistance can be increased considerably by the addition of Sc and Zr by forming L1 2 -precipitates in spaces between quasicrystalline precipitates. In this paper, we studied three alloys, two Al-Mn-Cu-Be alloys and an Al-Mn-Cu-Be-Sc-Zr alloy. The alloys were produced by vacuum induction melting and casting into a copper mould. We investigated the response of the alloys to different heat treatments and their heat resistance at higher temperatures. It was shown that the alloys could be precipitation strengthened by ageing at 300 °C and 400 °C. The hardness of the alloy stayed at relatively high levels even at 500 °C, while more substantial softening occurred at 600 °C.

Tetrahedral Profiled Carbon Rovings for Concrete Reinforcements

Abstract: Textile reinforcements have established themselves as a convincing alternative to conventional steel reinforcements in the building industry. Due to their high load-bearing capacities in addition to a smaller concrete cross section required, the bond between textile and concrete is extremely important. In contrast to ribbed steel bars ensuring a stable mechanical interlock with concrete (form fit), the bond force of carbon rovings has so far been transmitted primarily via the coating of the textile, i.e. by an adhesive bond with the concrete matrix (material fit). However, this material fit must be activated over relatively large yarn areas, which does not allow material-efficient utilization of the mechanical load capacity of the textile reinforcement. Solutions involving profiled rovings promise significant improvements in the bonding behavior by creating an additional mechanical interlock with the concrete matrix. In order to achieve a form-fit effect between roving and concrete, a roving geometry inspired by ribbed steel bars has to be created. For this purpose, an innovative profiling process was developed and implemented.

Corrosion Behavior of MoSi2 Coated Hastelloy X Utilized in Iodine -Sulfur Cycle for Hydrogen Production Application

Abstract: Molybdenum di silicide (MoSi2) has lower mismatch of coefficient of thermal expansion (CTE) with Hastelloy X as compare to silicon carbide. So, MoSi2 coatings can be a potential candidate to protect Hastelloy X against high temperature sulfuric acid. Herein, MoSi2 thin films were deposited via electron beam physical vapor deposition (EBPVD) method. Corrosion behavior of MoSi2 coated HX and bare HX was analyzed. Corrosion tests of bare Hastelloy X and coated samples was performed at different temperatures (60°C and 120°C) in 98% sulfuric acid using the weight-loss method. The morphology of pre and post corrosion test was also analyzed by using optical microscopy. Bare Hastelloy X showed a slight weight gain at 60°C and a weight loss at 120°C. The MoSi2 coated Hastelloy X showed slight weight gain at 60°C and a weight loss at 120 °C. The weight gain is the result of oxides formation whereas, weight loss may be attributed to corrosion due to H+ ions. These findings were also accompanied by optical microscopy as corroded and very rough patches were evident for bare HX, whereas, for MoSi2 coated samples, the coating was still intact.

The Residual Stress Modeling in Surface Plastic Deformation Machining Processes with the Metal Hardening Effect Consideration

Abstract: The metal workpiece Surface Layer (SL) Residual Stresses (RS) modeling and computational algorithms creation relevance is shown. The RS forming discrete elastoplastic finite element model at Surface Plastic Deformation (SPD) hardening treatment, including technological inheritance effect, is presented. A model feature is the complex non-monotonic types of metal loading and subsequent unloading and hardened body effect consideration, as well as residual stress tensor components evaluation as a result of these effects. Residual stress tensor components calculations in the workpiece hardened surface layer after treatment with different routines are performed. The metal hardening effect on the residual stresses values and distribution is established. The correlations between the residual stress tensor components and the main treatment routine parameters - the roller tension and profile radius are established.

Stiffness Modulus of Aged Asphalt Mixtures

Abstract: Asphalt mixtures have a dominant position in road construction in most countries. The choice of asphalt mixture type and surface depends mainly on the traffic loading and climatic conditions. The stiffness of asphalt mixture is one of important parameters that determines how road pavement performs and what pavement response to traffic loading. The stiffness modulus of the asphalt mixture changes during its service life, it tends to increase. During this process the mixtures in pavement age and degrade. Aging of asphalt mixtures has a significant effect on changes in the properties of individual mixtures. Presented research was focused on monitoring the change in the stiffness modulus of two asphalt mixtures AC11 50/70 and AC11 PMB 45/80-75 by the effect of aging. The asphalt mixtures have been exposed to the effects of short-term and long-term ageing by the conditioning of loose mixture method. After aging of the asphalt mixtures, the stiffness modulus of compacted asphalt mixture samples was measured. The stiffness modulus was determined using the IT-CY method at temperature of 10 °C, 20 °C and 30 °C and showed an increase after exposure of the mixture to short-term and long-term aging.

Heat-Resistant Al-Alloys with Quasicrystalline and L12- Precipitates

Abstract: We have been developing Al-Mn-Cu based alloys alloyed with minor additions of different elements. Small additions of beryllium enhance the formation of the icosahedral quasicrystalline phase (IQC) during solidification, especially during ageing. Upon solidification, primary IQC-particles may form, with sizes, ranging from 5 to 50 μm. IQC is also present as a part of binary eutectic in the interdendritic regions. More importantly, nanosized quasicrystalline precipitates can form during T5-treatment at temperatures ranging from about 250−450 °C. They are, in fact, metastable precipitates transforming to ternary T-precipitates (Al20Mn3Cu2) phase above 450 °C. The heat resistance can be increased considerably by the addition of Sc and Zr by forming L12-precipitates in spaces between quasicrystalline precipitates. In this paper, we studied three alloys, two Al-Mn-Cu-Be alloys and an Al-Mn-Cu-Be-Sc-Zr alloy. The alloys were produced by vacuum induction melting and casting into a copper mould. We investigated the response of the alloys to different heat treatments and their heat resistance at higher temperatures. It was shown that the alloys could be precipitation strengthened by ageing at 300 °C and 400 °C. The hardness of the alloy stayed at relatively high levels even at 500 °C, while more substantial softening occurred at 600 °C.

Formability of Aluminum in Incremental Sheet Forming

Abstract: Single point incremental forming (SPIF) process is used to deform complex shapes. Through SPIF process metallic sheet is formed. The formability of a AA5052 is evaluated using SPIF method for industry level product. The utility of SPIF is broad in industries because of the simple operating system of manufacturing and designing metal substances throughout computer design combined with the CNC machine. While forming Mantellic sheet there are many benefits. This process is extensively adopted in automobile, aeronautical, and medical industries for engineering complex parts. In this paper, the main objective is to examine the formability of AA5052 aluminum alloy raw material with various wall angles and operating boundaries using the modified computer numerical control (CNC) milling machine. Here, the shape correctness and the surface roughness are focused for computing the forming depth, wall angle, and spring-back for obtaining improved parts with a proper material with finish surface. For verifying the real-time experiments and evaluating the existence of stress, strain, and thickness variations.

Recent Progress on Single-Crystal Growth and Epitaxial Growth of 4H Silicon Carbide

Abstract: The review article describes the recent progress on SiC single-crystal and epitaxial growth technology. SiC is a third-generation semiconducting material with wide bandgap and high electrical breakdown field. Thanks to its excellent properties, it becomes an advantageous material in the field of high-temperature and high-power electronic device applications. Power devices fabricated of SiC are able to be operated at higher power density and higher switching frequency. This review focus on the growth, doping control and defect control of SiC single-crystal ingot and epilayer. The process of PVT, CVD, defect control, doping control and some recent applications of SiC are described. Various types of defects are described, including Micropipes, Dislocations, Stacking Faults etc. The wafering and polishing technology are also described.

Strengthening of Concrete Structures Using UHPC

Abstract: UHPC (ultra-high performance concrete) is an excellent material applicable also for strengthening of existing structures. Recently published papers were focused mainly on the behaviour of strengthened slabs subjected to bending, in this paper, experiments on punching and on strengthening of columns are mentioned. Strengthening of bridge decks requires a special composition of UHPC with high fibre contents and with the ability of casting in the slope. The appropriate mix for UHPC was developed within the research project. The experience gained from the extensive experimental program resulted in development of rules for strengthening of existing structures using UHPC, which follow the European codes and Czech recommendations for design of structures made of UHPC.

Oscillation and Stepwise of Hydrocarbon Melting Temperatures as a Marker of their Cluster Structure

Abstract: The presence of melting temperatures oscillatory and stepwise changes for hydrocarbons four homologous series is demonstrated and analyzed. The oscillating dependence is manifesteds on the principle of «even-odd» molecules with different deviations from linearity. According to the working hypothesis, this is due to the presence of the matter smallest structural unit in the cluster form of with a certain coordination number. The oscillation of melting temperatures in hydrocarbons series is explained by the fact that clustering can occur both at the site of the final carbon in the molecule and at other carbons in the molecule chain, and this fact depends on the «even-odd» effect. Based on the known values of melting temperatures in homologous series, the clusters probable structure is assumed. It is shown that graphs for the calculated values of equivalent lengths of these clusters correlate with corresponding graphs for hydrocarbons melting temperatures. An approximation formula has been developed to predict melting temperatures of hydrocarbons based on the values of the equivalent length and the cluster molecular weight, which operates with an approximation coefficient of 0.997 and a mean deviation of 4.2 K.

Preparation of Non-Enzymatic Glucose Sensing Nanocomposite Based on NiCo2O4 Nanosheets@ Reduced Graphene Oxide and Design of Glucose Detection System

Abstract: A non-enzymatic glucose sensing nanomaterial which consists of the NiCo2O4 nanosheets grown on reduced graphene oxide (NiCo2O4@rGO) is synthesized by a simple co-precipitation procedure. Firstly, the morphology and composition of the NiCo2O4@rGO are analyzed. Subsequently, the glucose sensing characteristics of the NiCo2O4@rGO are researched by Cyclic Voltammetry and Amperometry. The test results show that the prepared NiCo2O4@rGO has excellent glucose sensing properties. In the two linear detection range of 0.01mM-5.50mM and 5.50mM-15.50mM, the sensitivity reaches 4372.9μA·mM-1cm-2 and 1686.1μA·mM-1cm-2, respectively. In addition, in order to reduce the cost of electrochemical testing and improve the convenience and practicability of detection, a portable potentiostatic glucose detection system based on three electrodes is designed. Through testing, it is found that the non-enzymatic glucose detection system based on NiCo2O4@rGO has good practical application potential in the field of glucose detection.

Design of Shape Memory Micro-Actuator Modules with Sequential Actuation

Abstract: Shape memory alloy film-based micro-actuators have their behaviour controlled by a change in the thermomechanical stress that occurs in the bimorph - shape memory alloy film plus substrate assembly. The modification of the composition of the shape memory alloy leads to a change of the transformation temperature and implicitly of the temperature at which the stress change takes place in the bimorph. The design of micro-actuator blocks in which the composition and/or the temperature control mode of each micro-actuator in the block allows to obtain successive or sequential transformation sequences. The paper analyses the case of cantilever actuator modules with films of different compositions, deposited on the same substrate. It is highlighted how the composition of the alloy film with shape memory influences the modification of the curvature of bimorph cantilever type actuators in the studied block.

Phase Equilibrium in the Ternary CeО2-La2O3-Yb2O3 System at 1500 °С

Abstract: Materials based on cerium oxides and REE are perspective for use in medicine, energy and mechanical engineering due to the uniqueness of their authorities. Stationary system diagrams are the physicochemical basis for the creation of such materials as solid electrolytes for fuel comics, oxygen gas sensors, catalyst carriers, protected coatings for alloys, etc. In this work, phase equilibria and structural transformations in the system CeO2-La2O3-Yb2O3 at a temperature of 1500 oС in all international concentrations are investigated by the methods of microstistructural and X - ray phase analysis. It is established that in the triple system CeO2-La2O3-Yb2O3 fields of solid solutions based on cubic (F) modification of the structure of the structure of fluorite CeO2, monoclinic (B) and cubic (C) modification of Yb2O3 and hexagonal (A) modification of La2O3 (R) are used, which crystallizes in a Perovski-type structure with rhombic curvatures. It was found that the rarefaction of CeO2 in the crystal lattice of the ordered phase with the structure of the perovskite type LaYbO3 (R) is ~ 3 mol. %. Isothermal review of the state diagram of the systems CeO2-La2O3-Yb2O3 at reveals the presence of two three-phase (F + C + R), (A + R + F) and five two-phase (A + F), (A + R), (R + C), (F + R), (F + C) regions.

Effect of Vibrations on the Weld-Line Strength of Injection Molded Products

Abstract: In this research, vibrations were added to the mold structure. In the molding process, each vibration was turned on during the filling process. Moreover, the mold structure was re-designed to insert the vibration equipment. The design of this equipment is an early version used to insert vibrations. This option was chosen to facilitate the process of manufacturing and installing the vibration part. However, the applied method still has some limitations, such as not exerting an impact on the exact position where the weld line occurs. To overcome this disadvantage and to help increase the vibrations of the insert, we used a flexure hinge placed inside the insert. This design helped to improve the flow disturbance and to accurately impact the position where the weld line occurred. Therefore, the results of our method are better than those of the method currently being applied.

Study on Flow Stress Model of AA5005 Material

Abstract: Due to the continuous emergence of new alloys and the improvement of basic research requirements for aluminum alloy, researchers need to further study the flow constitutive relationship of new aluminum alloys. This paper used Model MTS-810 tensile machine to conduct tensile tests on AA5005 aluminum alloy at temperature of 360°C and strain rate of . Hollomon model, Swift model, Voce model, Voce+Voce model were used to compare the fitting accuracy with the experimental stress-strain curves, and the fitting parameters required by each formula were obtained from the fitting results, so as to obtain the constitutive model of AA5005 aluminum alloy. The Voce+Voce model which with more fitting freedom degree, lower flow stress increasing rate and saturation rate is most suitable to describe flow stress relation of aluminum alloy AA5005.

Dependence of Lignosulfonate Plasticizer Efficiency on the Activator Concentration in Alkali-Activated Blast Furnace Slag Paste

Abstract: Alkali-activated materials are a low carbon alternative for Ordinary Portland cement in the building industry. However, the effectiveness of commercially available cementitious plasticizers is often an issue. The present study deals with the workability, setting time, and mechanical properties of alkali-activated blast furnace slag (AAS) systems with different addition of lignosulfonate plasticizer (0; 0.5 and 1.0%) and various concentrations of alkaline activator (sodium hydroxide with concentration of Na+ ranging from zero to 12 mol∙dm−3 was used for these purposes). The workability of AAS was determined using the slump test according to EN 1015-3. Then the Vicat apparatus as described in EN 196-3 was used for measurement of the setting time. The effect of activator dose and plasticizer addition on the mechanical properties was determined using the determination of compressive and tensile strength in bending. A positive effect of the addition of a plasticizer in a certain concentration range on the workability was observed, but at the same time, the setting time is prolonged. The optimal concentration of NaOH seems to be of 2–4 mol∙dm−3 regarding the development of mechanical properties and workability.

Research on High-Temperature Constitutive Relationship of Aluminum Alloy

Abstract: On the worldwide tendency of wight reduction of automobile, aluminum is drawing a large number of researcher’s sights because it’s advantages of low weight, corrosion resistance, flexible and so on. Aimed at understanding high-temperature flow behavior of aluminum alloy A5005, tensile tests were conducted at temperatures 360°C, 430°C, 500°C and strain rates 0.0003s-1, 0.003s-1, 0.03s-1 respectively. For constitutive equation molding, a simplified Johnson-Cook model was adopted to describe high-temperature relationship of A5005 alloy. One of superiorities of this model is the flow stress model can be established more efficiently. What’s more, adiabatic temperature rise is eliminated by introducing development trend of material stress and strain in this model. Finally, the root mean square error (RMSE) was used to check the accuracy of the final model. The results show that the model accuracy increase by temperature increasing and strain rate decreasing, and the simplified Johnson-Cook model can describe stress-strain tendency without losing much accuracy.

Control of Amount of α-Al Phase Particles in near Eutectic Al-Si Alloy by Electromagnetic Stirring

Abstract: Al-Si alloy is widely used as a casting alloy. The α-Al phase in the semi-solid state has low Si content in the Al-Si alloy. Then by separation of these α-Al phases from semi-solid Al-Si alloy, refining of aluminum can be possible. But, in near eutectic Al-Si alloy, few primary α-Al phases can be crystallized. If the fraction ratio of the α-Al phase can be increased, near eutectic Al-Si alloy can refine, and this method can be used for recycling. In this study, the effect of electromagnetic stirring (EMS) on the microstructure, especially the amount of the α-Al phase particles was investigated. A rotational magnetic field was applied to JIS ADC12 alloy which has near eutectic content during slow cooling from the liquid state to the solid-state, by using a three-phase AC coil. By applying EMS at solidification, the shape of the α-Al phase became particle shape from dendrite shape, and the amount of α-Al phase particles was increased. Moreover, by applying unidirectional intermittent EMS, the volume fraction of α-Al phase particles was decreased with increasing intermittent applying time. In ADC12 alloy, the primary α-Al phases can be crystallized only 10% generally, but it could be obtained over 40% by applying EMS. This means that the semi-solid slurry of near eutectic alloy with over 40% of fraction solid can be obtained by applying EMS.

A Novel Approach for Proximate Analysis of Soil Corrosion Condition in Imadol-Sanagaun and Kantipur Colony Areas of Nepal

Abstract: The catastrophe failures of the underground water pipelines, made by Fe-alloys have been largely reported in Nepal, mostly due to the unwanted electrochemical interactions in the interfacial regions between the aggressive soils and external pipe surfaces. To cope with such pipe corrosion, this study was put forward a novel probabilistic approach for the proximate analysis of the corrosive grade of soils to the pipes with the improvement of the previously practiced ASTM, AWWA, and NACE classifying methods. In this non-deterministic approach, four corrosive groups were firstly classified based on the quantitative data of 6 soil properties, which were further classified into ten sub-corrosion groups by considering the sum of the cumulative point of each soil sample. The proximate soil analysis of twenty-four samples of the Sanagaun-Imadol (SNG-IDL) and Kantipur (KNT) housing areas of Lalitpur metropolitan (Kathmandu Valley) was performed to evaluate their corrosion conditions and to draw a corrosive soil mapping. The results of such proximate analysis under the probabilistic approach disclosed that ~ 92% of the total 24 soils of the study areas belonged to five specific sub-corrosion groups, which are considered the members of two corrosion groups, i.e., less and mildly corrosion groups.

Investigation of Hybrid Modification of Eco-Friendly Polymers by Humic Substances

Abstract: Research on investigation of hybrid eco-friendly polymers modificated by humic substances are given in this article. The purpose of the research is to investigate a hybrid modification of eco-friendly polymers of polylactic acid by humic substances, it was found that the mechanism of hybrid modification in the matrix synthesis of the polylactic acid-humic substances system indicates an intermolecular bond between polylactic acid and humic substances, at the same time, due to increased crystallization and the emergence of intermolecular and ester bonds in the formation of more rigid mesh structure in the system polylactic acid-humic substances is increasing the mechanical properties of such materials. It was found that the increase in the impact strength and the breaking stress during bending in the polylactic acid-humic substances system in the hybrid modification occurs, while the optimal content of humic substances in the polylactic acid-humic substances systems is 0.5 % by mass.

Technology of Preparing Ceramsite from Electric Ceramic Waste

Abstract: With the popularization of electricity, the use of electric porcelain is becoming more and more extensive, but in the process of production, the waste of electric porcelain continues to accumulate and increase, which not only pollutes the environment but also affects the normal life of human beings. Therefore, it is urgent to deal with these electric porcelain wastes. In this paper, the electric ceramic waste is used as the main raw material, and starch and kaolin are added to optimize the formula to prepare porous ceramsite. The effects of the content of electrical ceramic waste, sintering temperature and holding time on the properties of porous ceramsite were studied. After research, the results show that with the increase of waste content, the porosity and water absorption first decrease and then increase, while the compressive strength first increases and then decreases. With the increase of the sintering temperature, the porosity and the water absorption rate decrease continuously at the beginning, and the compressive strength increases continuously at the beginning, but when the sintering temperature increases continuously, there will be a turning point or a flattening point. With the continuous extension of the holding time, the water absorption and porosity continue to increase, while the compressive strength continues to decrease, but the overall change is small. The optimization can be found that when the waste content is 75%, the sintering temperature is 1200 °C, and the holding time is 30 min, the prepared porous ceramsite has the best performance. Its water absorption rate: 13.87%, porosity: 27.52%, compressive strength: 20.06MPa.

Effect of Solute Ta on Grain Refinement of Al-7Si-0.3Mg Based Alloys

Abstract: Different Ta concentrations together with stochiometric grain refiner (Al-2.2Ti-1B) in Al-Si-Mg based alloys were investigated with the aim to elucidate grain refinement mechanisms. Post-solidification microstructure was characterised using optical microscopy and scanning electron microscopy (SEM), with a special focus on the Ta-rich layer (more likely to be Al 3 Ta) on the basal planes (0001) of TiB 2 . A significant grain refinement was observed by using the solute Ta together with stochiometric grain refiner (Al-2.2Ti-1B). In order to further elucidate the formation of Ta-rich layer on the basal planes (0001) of TiB 2 , the Density Functional Theory (DFT) calculation were also performed to determine the interface energies of different interfaces and sandwich configurations, including Al (111), Al 3 Ti (112) and Al 3 Ta (112) at the interface of TiB 2 basal plane (0001). It was found that the interface energy for Ti-terminated TiB 2 at the interface throughout all configurations involved in this paper is lower than that for B-terminated TiB 2 , indicating that Ti-terminated TiB 2 is more favourable. It was also found that the Al 3 Ta configuration yields the same interface energies as the Al 3 Ti configuration. Furthermore, the interface energy of the sandwich configuration also shows nearly identical values along the TiB 2 // Al 3 Ti and TiB 2 // Al 3 Ta interface energy, strongly indicating that the solute Ti can be fully replaced by the solute Ta.

Applying FCCCD Response Surface Method in Studying the Cutting Power of Wood Materials

Abstract: For machine design, determining the machine’s technical specifications as the basis for design element computation and choosing an appropriate electric motor are among the most crucial tasks. Especially, considering the scarcity of studies about tropical wood materials, it is more important to determine the specific work by the experimental approach. The scope of the study includes the research of dependency of the cutting power on the working parameters such as feed per tooth Sz, the cutting depth h, and the tooltip’s radius r in the process of wood material machining. Employing the response surface method, the experiments following the Central Composite Face design (FCCCD) plan were undertaken with 4 replicates. The author used Minitab software to process experimental results, analyze the regression equation and variance (ANOVA). In addition, the cutting force components in wood milling is also determined, which is the basis for the design of machine elements of wood milling machines and CNC woodworking machines.

Development of a Testing Protocol to Assess the Washability of E-Textiles

Abstract: Most e-textiles are developed for wearable use and thus need to be washable to guarantee a textile typical usability. Yet, there are no e-textile specific wash testing standards and as a result, employed testing protocols vary greatly, resulting in a lack of comparability. To address this issue, an e-textile wash testing protocol modelled after testing methods provided by the standard ISO 6330 (the standard currently most often used as a basis for e-textile wash testing) as well as gentle household washing methods was developed and verified regarding its cleaning capability.

Study of Durable Strength of Steel Mining and Metallurgical Equipment

Abstract: Erosion of the metal of mining and metallurgical equipment due to the impact of solid particles is one of the forms of wear that can significantly limit the service life of a working machine or technological equipment, for example, a pipeline conveyor, loading and unloading bodies of mine workings and metallurgical machines. At present, this problem has been little studied and there is not enough information in the literature to form a systematic picture of impact erosion of equipment elements of mining and processing plants. The purpose of the research was to study the fatigue strength and corrosion-mechanical crack resistance of some structural elements of mining and metallurgical equipment with a long service life in chemically aggressive environments. Experimental tests for corrosion fatigue (long-term strength) were performed under bending load. The tests were performed on a bend with zero average voltage and a cycle frequency of 30 Hz. The tests were performed in salt solutions with a concentration of NaCl 5%. To compare the results, tests were sometimes performed in the air. The given data analysis shows that the long-term fatigue of the metal of mining and metallurgical equipment is significantly reduced when reaching 20 years of operation, especially in an aggressive environment containing chlorine ions, which causes severe corrosion damage to steel equipment. In addition, samples cut from metal with a long service life in mining and metallurgical conditions (more than 20 years) are characterized by low long-term strength. It has been found that fatigue resistance decreases with an increase in the number of cycles. Steel samples tested based on N = 10 6 and especially on the basis of N = 10 7 cycles have low resistance, which inevitably leads to breakdown with the subsequent destruction of equipment. It has been established that with an increase in the service life of the experimental mining and metallurgical equipment, the fracture toughness of the metal decreases significantly, which causes further failure and destruction of technological equipment.

Cluster Structure Control of Coatings by Electrochemical Coprecipitation of Metals to Obtain Target Technological Properties

Abstract: The article considers the possibility of controlling the macromolecular structure of ternary alloys in the form of compact coatings, which are obtained by electrochemical means. This method of obtaining metal clusters is more economical than from plasma one. The influence of the cluster structure of the synthesized coatings in the form of a triple alloy of polyligand complex electrolytes on their functional properties is shown. There are presented the results of testing coatings from this ternary alloy of different elemental and cluster composition for microhardness according to Vickers. The highest microhardness was obtained by the coating with the lowest molecular weight of the cluster, which provided a denser packing of atoms.

A И-Shaped Curve of Hot Tearing Susceptibility in Magsimal®-59-Based Alloys

Abstract: The hot tearing susceptibility of Al-6Mg-xSi (x = 0-6.0 wt.%) alloys was studied using constrained rod casting. Addition of Si content resulted in double ternary eutectic reactions and then changed the freezing range and eutectic liquid fraction greatly, which made the hot tearing susceptibility show a И-curve with the increasing of Si content. The И-curve was obviously different from the λ-curve that supported by most researchers.

Novel Knitting Vision - Modern Ways for Integral Knitting of Intelligent Gloves for Tactile Internet Applications

Abstract: The internet of things is a key driver for new developments in the fields of medicine, industry 4.0 and gaming. Consequently, the interaction of virtual and real world by smart interconnecting of devices in our everyday life is the basis idea of the Cluster of Excellence "Centre for Tactile Internet with Human-in-the-Loop" (CeTI) at TU Dresden. To enable a user-centric approach in CeTI innovative textile structures, mainly knitted smart gloves, and their functionalization by integration of sensors and sensory yarns are focus of research activities.

Characterizing the Effect of Processing Parameters on Temperature Distribution of 7075 Aluminum Alloy Slurry Prepared by Enthalpy Control Process

Abstract: There is a strong demand for high-strength aluminum alloys such as 7075 aluminum alloy to be applied for rheocasting industry. The overriding challenge for the application of 7075 alloy is that its solid fraction is very sensitive to the variation of temperature in the range of 40% ~ 50% solid fraction, which inevitably narrows down the processing window of slurry preparation for rheocasting process. Therefore, in this work, a novel method to prepare semi-solid slurry of the 7075 alloy, so called Enthalpy Control Process (ECP), has been developed to grapple with this issue. In the method, a medium-frequency electromagnetic field was applied on the outside of slurry preparation crucible to reduce the temperature difference throughout the slurry. The effect of processing parameters, including heating power, heating time, the initial temperature of crucible and melt weight, on the temperature field of the semi-solid slurry was investigated. The results exhibited that although the all the processing parameters had a great influence on the average temperature of the slurry, heating time was the main factor affecting the maximum temperature difference of the slurry. The optimum processing parameters during ECP were found to be heating power of 7.5 KW, the initial temperature of crucible of 30 °C ~ 200 °C and melt weight of 2 kg.