Properties Of Cladding Research Articles

Structure and Properties of Plasma Cladding of High-Speed Steel S2-9-2 (W2Mo9Al)

Structure and Properties of Plasma Cladding of High-Speed Steel S2-9-2 (W2Mo9Al)

Tuning the structure and properties of carbon cloth by FeCl3intercalation for efficient two-electron oxygen reduction catalysis.

The advancement of various energy conversion and storage technologies hinges on the development of efficient and stable electrocatalysts for the oxygen reduction reaction (ORR). In this study, we report the enhancement of carbon cloth (CC) for robust ORR through an FeCl3intercalation reaction. Utilizing a thermal annealing method, FeCl3was intercalated into the graphite structure on the surface of CC, resulting in the creation of numerous defects and the incorporation of Fe species. These newly introduced defects play a pivotal role in activating the ORR via a two-electron pathway. The presence of Fe species further stabilizes the catalytic activity, leading to efficient and stable ORR performance. Our findings highlight the significance of defect engineering and Fe species incorporation in carbon-based materials for improved ORR catalysis and pave the way for the development of advanced electrocatalysts for energy-related applications.

Investigation of the microstructure and tribological properties of laser cladding 5%Ti3SiC2 reinforced Co-based composite coatings under different loads over the wide temperature range

In order to improve the mechanical properties of SUS 304 in practical engineering application, Co-5%Ti3SiC2 coating was successfully prepared on SUS 304 by laser technology. The microstructure of Co-5%Ti3SiC2 coating was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD) to evaluate the tribological properties in detail. The relevant wear mechanism of the substrate and Co-5%Ti3SiC2 coating under different loads (2, 5 and 8 N) in isothermal tribological experiments (25 and 600 °C) were systematically explored. The results show that the Co-5%Ti3SiC2 coating is mainly composed of continuous matrix γ-Co solid solution, ceramic Fe2C, Cr7C3 and TiC, and lubricating phase Ti3SiC2. The average micro-hardness of Co-5%Ti3SiC2 coating is 358.61 HV0.5, which is significantly higher than that of SUS 304 (239.32 HV0.5). In all isothermal tribological experiments, the wear rate of Co-5%Ti3SiC2 coating decreases with the increase of load, and its coefficient of friction (COF) also decreases with the increase of load.

Online impulse purchases versus planned purchases and the role of visual attributes

ABSTRACT Given the rapid growth of online buying, there seems to be a significant gap in understanding how consumers derive satisfaction from their past online fashion purchases, particularly in the absence of tactile experiences, relying solely on visual aesthetics for both planned and impulse decisions. This gap examines the necessity of evaluating how online shopping platforms should cater to diverse consumer behaviors. The goal is to examine how the visual aesthetic attributes of fashion clothing purchased online, whether through impulse or planned decisions, can influence satisfaction through a conceptualized model. It incorporates several variables’ mediating and moderating roles for a more plausible explanation. Two distinct samples were drawn from consumers who independently made planned purchases and those who made impulse purchases, totalling 483 respondents in the survey. Multigroup Structural Equation Modeling was employed for data analysis. The findings reveal that visual aesthetics significantly and positively impact perceived risk, perceived quality, and satisfaction. Additionally, perceived risk positively influences perceived quality. However, perceived quality exhibits a negative relationship with satisfaction. Both impulse and planned behaviors significantly moderate the relationship, except for the value aesthetic attributes of fashion clothing and perceived risk for impulse buyers. This article contributes to the theoretical and practical implications.

Improvement of AISI 316L laser cladding properties by high-frequency vibration process

In the present paper, a unique laser cladding-assisted high-frequency vibration device was applied to prepare the AISI 316L cladding layer by laser cladding on the surface of the AISI 316L stainless steel substrate. The macroscopic morphology, microstructure, microhardness, and wear resistance of the cladding layer were analyzed by optical microscope, scanning electron microscope, Vickers microhardness tester, friction and wear tester, and three-dimensional optical profiler. The laser cladding-assisted high-frequency vibration device uses a high-frequency oscillator with a fixed frequency (20 KHz) to transfer vibration energy through the probe in contact with the substrate and close to the molten pool. This paper explores the effect of different laser powers on the dilution rate of the cladding layer, compares and observes the cross-sectional morphology and microstructure of the cladding layer with and without high-frequency vibration, and analyzes the reasons for the different results.

Research of the effects of laser power variation on the properties of laser cladding Ni45/Cr3C2/MoS2 self-lubricating wear-resistant coatings on the surface of 300M ultra-high-strength steel

Research of the effects of laser power variation on the properties of laser cladding Ni45/Cr3C2/MoS2 self-lubricating wear-resistant coatings on the surface of 300M ultra-high-strength steel

Testing and evaluation of light clothing properties used in fire and rescue service units

In the testing room for examination products of the Fire Engineering and Expert Institute (FEEI) of the Ministry of the Interior of the Slovak Republic in Bratislava, the Slovak National Accreditation Service SNAS has granted accreditation. Accredited testing room with identification number no. S-084 performs tests applied in the field of personal protective equipment. The goal is to specify, determine, and, above all, verify the selected characteristics for emergency clothing (light emergency clothing - LEC) used by firefighters and rescuers in the Fire and Rescue Service units to determine the conditions for procurement and quality control of the LEC supplied. The results obtained during the examination of the properties of light emergency clothing will be used in the next steps of the research of the Product Assessment Department (PAD) FEEI of the Ministry of the Interior of the Slovak Republic. In contrast, individual parameters can be used to design new LEC. The basic meaning and purpose of any protective means are to protect a person who intervenes in a dangerous environment contaminated with chemical, biological or radioactive substances, for example, in industrial accidents connected with the release of dangerous substances (HAZMAT), in accidents of vehicles transporting HAZMAT and natural disasters or fires of various nature. Protecting from the external environment is one of the favourable inherent properties of personal protective work equipment (PPE).

Impact of Nb and Zr on the precipitation evolution of Laves phase and the properties of laser cladding coating of AlCoCrFeNi high entropy alloy

The impact of Nb, Zr, and their synergies on the phase composition, wear and high oxidation resistance of a high entropy laser cladding coating consisting of AlCoCrFeNi on Q235 steel was thoroughly investigated in this work. From our analysis, it was demonstrated that the addition of Nb and Zr promoted the formation of the Laves phase except the BCC phase, and a small amount of MC phase was formed in the coatings containing Zr. Although both of them can refine the grain to different degrees, the grain refinement degree was the highest when they were added together. The solid solution strengthening, fine crystal strengthening, and Laves phase precipitation strengthening induced by the addition of Nb and Zr can significantly improve the microhardness of the coating, which was 1.1–1.5 times that of S1-S3 coatings. The formation of ternary Laves phase, grain refinement, and increase of the microhardness enhanced the plastic deformation and micro-cutting resistance of S4 coating, and the wear resistance was 1.3–2.5 times that of S1-S3 coatings. The unstable oxide Nb2O5 produced by the addition of Nb led to a reduction in the stability of the oxide layer. However, when the two were added cooperatively, the formation of unstable oxide Nb2O5 was reduced by the presence of Zr. Moreover, grain refinement was induced by the collaboration of the two making the protective oxide layer form faster, and stronger bonding with the coating, the high temperature oxidation resistance was significantly improved, which was 1.3–4.3 times that of S1-S3 coatings.

Climate change and heat stress resilient outdoor workers: findings from systematic literature review

PurposeGlobal warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially those working outdoors, as they often have limited access to cooling strategies. The present systematic literature review (a) summarizes the current knowledge on the impacts of climate change on outdoor workers, (b) provides historical background on this issue, (c) explores factors that reduce and increase thermal stress resilience, (d) discusses the heat mitigation strategies, and (e) provides an overview of existing policy and legal frameworks on occupational heat exposure among outdoor workers.Materials and methodsIn this systematic review, we searched scientific databases including Scopus (N = 855), Web of Science (N = 828), and PubMed (N = 202). Additionally, we identified relevant studies on climate change and heat-stress control measures through Google Scholar (N = 116) using specific search terms. In total, we monitored 2001 articles pertaining to worker populations (men = 2921; women = 627) in various outdoor climate conditions across 14 countries. After full-text assessment, 55 studies were selected for inclusion, and finally, 29 eligible papers were included for data extraction.ResultsFailure to implement effective control strategies for outdoor workers will result in decreased resilience to thermal stress. The findings underscore a lack of awareness regarding certain adaptation strategies and interventions aimed at preventing and enhancing resilience to the impact of climate change on heat stress prevalence among workers in outdoor tropical and subtropical environments. However, attractive alternative solutions from the aspects of economic and ecological sustainability in the overall assessment of heat stress resilience can be referred to acclimatization, shading, optimized clothing properties and planned breaks.ConclusionThe integration of climate change adaptation strategies into occupational health programs can enhance occupational heat resilience among outdoor workers. Conducting cost-benefit evaluations of health and safety measures for thermal stress adaptation strategies among outdoor workers is crucial for professionals and policymakers in low- and middle-income tropical and subtropical countries. In this respect, complementary measures targeting hydration, work-rest regimes, ventilated garments, self-pacing, and mechanization can be adopted to protect outdoor workers. Risk management strategies, adaptive measures, heat risk awareness, practical interventions, training programs, and protective policies should be implemented in hot-dry and hot-humid climates to boost the tolerance and resilience of outdoor workers.

Calculation of heat protective parameters of clothing packages by method simulation modeling (Monte Carlo method)

The heat-protective properties of clothing have been studied taking into account the influence of deterministic factors, and the influence of random factors on the heat-protective properties of clothing has not been studied. In this regard, to obtain objective values of indicators of the heat-protective properties of clothing, taking into account the nature of the distribution of factors for a batch of products that are random. Knowing the laws of distribution of random factors effectively, it is possible to carry out calculations of the thermal insulation properties of clothing material packages using the simulation method. The work has developed a method for calculating the thermophysical parameters of clothing packages based on simulations of random parameters distributed according to a normal law. For the calculation, an algorithm and calculation program were compiled in the Python programming language. The thermophysical parameters of the clothing package were calculated, and the influence of wind flow speed on them was analyzed. When calculating the wind flow speed, which have a significant impact on the values of the effective thermal conductivity coefficient of the packages and the values of the total coefficient of the packages, they are taken taking into account the Beaufort table and the recommendations of the Ministry of Emergency Situations of Kazakhstan. The developed program for calculating the thermophysical characteristics of a package of clothing materials allows to change the model parameters during the calculation process: introduce new layers of materials into the package, change the thermophysical and linear characteristics of individual layers of the package, change external conditions.

Effect of Substrate Preheating Temperature on the Microstructure and Properties of Laser Cladding Fe/TiC Composite Coating

Effect of Substrate Preheating Temperature on the Microstructure and Properties of Laser Cladding Fe/TiC Composite Coating

Effect of solution and artificial aging heat treatment on the hardness, friction and wear properties of laser cladding and roll-formed 18Ni300 materials

Abstract 18Ni300 is widely used in precision moulds, national defence, and other engineering fields due to its high strength and toughness, and because its properties can be greatly changed after heat treatment. In this research, the 18Ni300 cladding layer was fabricated on 18Ni300 substrate using the laser cladding method and a solid solution artificial aging treatment was carried out to analyse its macro morphology and metallographic organization. Comparison of hardness, friction, and wear of cladding layers manufactured by laser cladding and of materials produced by rolling was performed before and after heat treatment. The results show that the solution and artificial aging heat treatment has a significant effect on the microstructure of the cladding layer fabricated by laser cladding. There are obvious differences in the organization and morphology of different parts of the cladding layer before heat treatment; the metallographic organization and morphology of different parts of the cladding layer after heat treatment are the same. The trend of change of material hardness before and after heat treatment is the same in that the cladding layer is greater than the rolled material and the hardness of the material after heat treatment is much greater than the hardness of the material before heat treatment. The hardness and wear resistance of the material after solution and artificial aging heat treatment has been significantly improved, and the impact on the rolled production material of the melted cladding layer manufactured by laser cladding is even greater.

Research on microstructure and properties of laser cladding Ti-Al-WC composite coating on TC4 surface

Abstract To improve the surface properties of TC4, laser cladding was used to prepare Ti-Al-WC composite coatings with varying WC content on the surface of TC4. XRD and SEM were used to examine the physical phase composition and microstructure of the coatings. At various WC contents, the microhardness distribution and wear friction properties of the coatings were also examined. The results revealed a strong metallurgical connection between the cladding layer and the matrix. When no WC was present, the coating was mostly formed of TiAl and Ti3Al phases; however, when WC was present, the coating also contained WC, TiC, W2C, and MAX phases, as well as a minor amount of partially dissolved WC particles. When compared to the substrate, the average hardness of the coating was increased by 1.08-1.76 times. When the WC content was 20 and the wear amount was 1.9 mg, the best wear resistance was obtained. Mainly abrasive and adhesive wear was observed.

Comparison of laser cladding properties of tantalum and tantalum pentoxide powders on titanium substrates

Comparison of laser cladding properties of tantalum and tantalum pentoxide powders on titanium substrates

Statistical modeling and optimization of clad geometry in laser cladding of Amdry 961 on Inconel 713LC superalloy with response surface methodology

In this study, Inconel 713LC superalloy was laser-clad with Amdry 961 powder using a 1 kW fiber laser. Response surface methodology was used to investigate the effect of laser power, duty cycle, and scanning speed on the deposited bead's geometry (width, height, and clad angle) and the dilution ratio. Interestingly, higher laser power and duty cycle increased bead width, clad angle, and dilution ratio but decreased bead height, while the opposite effect was observed for scanning speed. The process optimization was performed by a simultaneous optimization technique. This technique identified the ideal parameters: a laser power of 840 W, a duty cycle of 79.5%, and a scanning speed of 4.38 mm/s. These settings effectively optimized clad properties, with mean absolute errors of 7.96% for clad width, 14.74% for clad height, 16.71% for clad angle, and 5.166% for dilution ratio. These values demonstrate the precision of optimized parameter settings.

Contribution of the prominent Russian hygienist F. G. Krotkov to the development and practical use of military uniforms

The article presents some historical information about the origin and development of the doctrine of clothing in general and military clothing in particular. The data on the conduct of research on the hygienic properties of clothing and shoes by domestic military hygienists are presented. The role of F. G. Krotkov in the development of scientifically based requirements for military uniforms, the relevance of which remains to the present time, is emphasized.

Protective and Comfort Performance of Fire Protective Clothing

The study examined the fire protection performance of several woven products. Given that the comfort and fire protection properties of fire protective clothing (FPC) are opposite, it is important to consider the specific needs of firefighters when selecting the most suitable structure from various plain-woven derivatives, such as plain, basket, and ripstop. The yarn used was Nomex IIIA, which is a type of meta-aramid fibre. To achieve different thread densities, the pick density was adjusted while keeping the end density constant. The physical characteristics, thermal protective performance, thermal resistance, thermal conductivity, water vapour transmission rate and air permeability of all samples were assessed according to the appropriate standards. The goal was to identify the weave structure with the highest performance and the most optimal thread density. The basket weave structure was proposed as a fire protective clothing (FPC) having comfort qualities at a moderate level. Furthermore, increased density provided enhanced fire resistance, however, comfort must be sacrificed. Thus, to achieve a balance between fire protection and comfort, it was recommended to choose a thread density that is of an average level and the suggestion made by this research is to use the fabric as a basket weave design with an ends per inch of approximately 42, it is recommended to retain the pick density within the range of 46 with 44 tex Nomex IIIA yarn. The results of this study may be replicated in other designs using Nomex IIIA and comparable types of cloth and weave specifications.

Super hydrophobic coating and oil-water separation based on modified titanium dioxide and glycerol ethers

At present, the super hydrophobic surface is mostly constructed with siloxane colloid and fluoropolymer. The super hydrophobic surface can be broken by fine friction, and its acid-base resistance is poor. In this paper, firstly titanium dioxide (TiO2@GDE) was modified by ethylene glycol diglycyl ether (GDE). TiO2@GDE was mixed with dodecanoic acid (DA), perfluorodecyl triethoxysilane (PFTS) and GDE to make super hydrophobic mixture. By soaking in this mixture, the super hydrophobic surface of cotton cloth (SHC) was obtained. Among them, GDE is used as a cross-linking agent to cross-link PFTS, DA, TiO2@GDE and facial surface. PFTS and DA are used to reduce the surface energy, and TiO2@GDE is used to improve the surface roughness of cotton cloth. Secondly, the effects of construction condition parameters on the water contact angle and water rolling angle of SHC were explored. The results showed that the optimal mixture concentration was 20 g/L, soaking time was 30 min, drying temperature was 100 °C, and drying time was 2 h. Under the optimal conditions, the surface water contact angle (WCA) of the modified cotton cloth is 164±3°, and the water rolling angle is 9±3°. Finally, the obtained SHC is used for oil-water separation. Whether trichloromethane, or n-hexane and dichloromethane, separation efficiency can reach more than 99%. Whether it is the next oil-water separation directly after the completion of the last oil-water separation without drying, or the next oil-water separation after the completion of the last oil-water separation after drying, more than 10 times of oil-water separation can be carried out, and the separation efficiency can reach more than 98%. In addition, the self-cleaning property, durability, friction resistance and acid/alkali resistance of the SHC were tested, and the results were good. At the same time, the whiteness, thickness, gloss and CIELAB color are tested. The results show that the super hydrophobic coating constructed has little change in the physical properties of cotton cloth.

Analysis of the thermal expansion and mechanical properties of laser cladding of Invar alloy

Analysis of the thermal expansion and mechanical properties of laser cladding of Invar alloy

Effect of Scanning Speed on Microstructure and Properties of Laser Cladding Fe‐0.3C‐15Cr‐1Ni High Hardness Corrosion‐Resistant Alloy Coating on 3Cr13 Surface

Fe‐0.3C‐15Cr‐1Ni high hardness corrosion‐resistant alloy coating is prepared on the surface of 3Cr13 by laser cladding technology. The effects of scanning speeds on the microstructure, microhardness, and corrosion resistance of the coating are studied. The results show that the microstructure of the cladding layer is mainly composed of intracrystalline martensite and carbides distributed along the grain boundaries. When scanning speed increases from 3 to 5 mm s−1, the grain is obviously fined, and the number of carbides increases, further increasing scanning speed, the grain refinement degree decreases and the carbide quantity decreases gradually. When scanning speed is 5 mm s−1, the microhardness reaches the maximum, the corrosion resistance is significantly improved at 5 and 7 mm s−1, and the pitting potential and passivation zone width increase by 180–219% and 69–78%, respectively, compared with 3 mm s−1 sample, but further increases scanning speed to 9 mm s−1, the hardness and corrosion resistance significantly reduce. This is because scanning rate affects the component undercooling degree of the dynamic molten pool and the temperature gradient at the solidification interface front, which affects the growth of dendrites, the number of carbides, and further affects the alloying elements in the carbide and matrix.