Development of a Method for Obtaining a Wear-Resistant Coating for a Cutting Tool

The article presents a method for producing a nanostructured wear-resistant high-hard coating with high physicomechanical and strength characteristics, resistance to shock and vibration loads. The result is an increase in adhesion between the substrate and the coating, as well as an increase in microhardness. One of the common methods of metal cutting is band-cutting machines that use closed band saws as cutting tools. Since materials with high physicomechanical characteristics (hardness, strength, etc.) are increasingly being used in modern production, which significantly complicates the cutting process and makes increased demands on the cutting tool. To expand the range of processed materials for which the productive use of band-cutting machines is possible, it became necessary to create a band saw with higher cutting characteristics. At the same time, the specificity of the working conditions of the band saw shows that the blade should have such characteristics as increased vibration resistance, resistance to alternating and dynamic loads, and the cutting part of the saw should have increased resistance to shock, dynamic, alternating loads, have high hardness, as well as increased wear resistance.

Gypsum Compositions Modified with Metallurgical Wastes

The main results of the study of the influence of man-made products of the metallurgical industry on the properties and structure of gypsum binder are presented. It has been proved that the introduction of man-made modifiers, metallurgical dust, and slag leads to an increase in the strength properties and electric conductivity of the material, but, over time, the waste efficiency decreases. The use of Portland cement as an activator leads to the formation of amorphous hydration products based on calcium hydrosilicates, which bind calcium sulfate crystals and provide an increase in the physicomechanical characteristics and electric behavior of the gypsum composite.

Effect of Fiber Stripes of COVID-19 Healthy Personal Materials On Durability, And Physicomechanical Characteristic of Concrete For Decorative Landscape Pavements And Artificial Rocks

This research presents a new method for determining the impact of healthy personal protection materials HPPM stripes, such as surgical masks, protective suits, overhead and safety foot shoes, on the durability, physicomechanical characteristics of concrete for use in architectural forms. As a result of the current global epidemic caused by Coronavirus, the use of (HPPM) such as surgical masks, protective suits, overhead and safety foot shoes has increased considerably (COVID-19). COVID-19's second and third waves are currently affecting various countries, necessitating the use of face masks (FM). As a result, millions of single FS have been discharged into the wild, washing up on beaches, floating beneath the seas, and winding up in hazardous locations. The effect of stripes fibers on physicomechanical aspects of concrete, such as workability, UCS, FS, IMs, spalling, and AbR; sorptivity, Sw; n; water penetration, permeability, and economic and eco-friendly aspects, was also discussed. With a focus on HPPM especially single-use face masks, this research investigates an innovative way for incorporating pandemic waste into concrete structures. SEM and XRD were also employed to analyze microstructures and the interfacial transition zone, as well as to identify the elements. HPPM was found to have a pore-blocking effect, which reduced permeability and capillary porosity. It was also discovered that the best concentrations of HPPM, particularly masks, were applied by volume at 0 %, 0.1, 1.5, 2.0, and 2.5 %. The usage of single-use face masks increased the strength qualities and overall performance of the concrete samples. The tendency of growing strength began to disappear around 2%. The results of this investigation show that stripe content has no effect on compressive strength. The stripe, on the other hand, is critical in determining the flexural strength of concrete. A SEM was used to analyze the microstructure of concrete. HPPM fibers are discovered to act as bridges across cracks, enhancing the matrixes transfer capability. From a technological and environmental standpoint, the study found that using healthy personal protection materials fiber in the production of concrete is viable.

Experimentally Predicted Optimum Processing Parameters Assisted by Numerical Analysis on the Multi-physicomechanical Characteristics of Coir Fiber Reinforced Recycled High Density Polyethylene Composites

This paper presents the analysis of processing parameters in the fabrication of coir fiber recycled high density polyethylene composite through experimental data and Taguchi grey relational analysis. Three processing parameters; fiber conditions, fiber length, and fiber loading with mixed level design, having orthogonal array L32 (2**1 4**2) were employed in the preparation of polymer composite. Numerical analysis assisted by Taguchi design was conducted on the experimental multi-physicomechanical characteristics of the polymer composite for optimum processing parameters. The optimum grey relational grade was gotten to be 0.8286 and was experimentally validated with 95% confidence interval. The optimum processing parameters were discovered to be a treated fiber having 8 mm length at 30% loading. Although, other processing parameters are significant, but fiber loading is the most significant parameter. Correspondingly, the contribution of residual error on the overall multi-physicomechanical characteristics is insignificant having 2.43% of contribution.

Determination of Physicomechanical Characteristics of the Cement Mortar with Added Fiberglass Waste Treated with Hydrogen Plasma

Solving the environmental problems and the economic aspects of the construction sector represent a global priority. The considerable quantities of raw materials and the energy consumed by this sector make it one of the most polluting economic activities. Fiberglass in various forms is widely used in the construction sector. In the manufacturing process and during the usage of fiberglass products, a significant amount of indestructible waste results, negatively impacting the environment. An innovative solution for utilizing this type of waste is the treatment with hydrogen plasma. This process results in two products: the first in the gaseous state used to obtain synthetic fuel and the second in solid-state, named slag. The composition of solid waste contains chemical compounds that can increase their strength if used as additives in mortars or concretes. This study presents the laboratory tests on mortars, in which a part of the cement amount was replaced with the solid component resulting from the plasma treatment of glass fiber waste. The results showed that replacing a part of the cement with these materials is a solution that minimizes the ecological footprint of the buildings.

THE EQUIPMENT FOR DEFINITION OF PHYSICOMECHANICAL CHARACTERISTICS OF MATERIALS BY PRESS-IN METHOD (review)

The article considers the main methods for determining the hardness of materials. The basic formulas for calculating the mechanical characteristics of materials by hardness values are presented. The analysis of methods for calculating tensile diagrams of materials by indentation diagrams is carried out. The paper considers the approaches to building a finite element model of material indentation The need to improve existing standards and develop computational methods is shown with a detailed description of techniques for recalculating indentation diagrams into mechanical characteristics of materials.

Reactive extrusion of nanocomposites based on ethylene copolimers and mineral fillers

The paper presents the results of a study of the influence of the temperature regime of reaction extrusion on the main physicomechanical characteristics of nanocomposites based on copolymers of ethylene with butylene and ethylene with hexene and natural minerals - clinoptilolite and vesuvian. The optimal temperature regime of extrusion of nanocomposites based on copolymers of ethylene and natural minerals was established. At a maximum extrusion temperature of 230 °C in the dosing zone, counterflow increases, which contributes to an increase in the residence time of the nanocomposite melt and, accordingly, to a decrease in extruder productivity. The possibility of mechanochemical synthesis of nanocomposites vulcanized with dicumyl peroxide on an extruder using monotreme technology has been proved. It was found that as a result of vulcanization of nanocomposites based on ethylene copolymers, a significant increase in the ultimate tensile stress and a decrease in the elongation at break are observed. With an increase in the maximum extrusion temperature in the extruder head to 230 °C, it does not lead to the appearance of a counterflow. At the same time, it was shown that with an increase in the temperature regime of extrusion of vulcanized nanocomposites over 200 °C, the time spent by the melt in the material cylinder practically does not undergo changes. A fundamental feature of the effect of chemical crosslinking with dicumyl peroxide on the processing process and the regularity of changes in the properties of nanocomposites are established. The probable mechanism of the vulcanization process in the melt of the polymer matrix and its selective effect on the reaction extrusion process, structural features and properties of nanocomposites are presented.

Study Smart-layer effect on the physical and mechanical characteristics of the samples from polymer composite materials under quasi-static loading

Currently, developments of the so-called Smart-constructions are relevant as they enable a real-time monitoring of changes in required values. Smart designs are widely used in the construction, automotive and aerospace industries. Technologies of creating products from polymer composite materials make it possible to introduce various sensors directly into the structure of a material, thereby create systems monitoring the state of structures. The most recommended for such implementation are fiber-optic sensors, which have a number of advantages over other sensors (luminescent, strain gauge, piezoelectric ones). However, when introducing the fiber-optic sensors, there is a number of difficulties, which are primarily associated with fragility of the optical fiber and lead to the breakdown of fiber-optic lines. As a result, it is necessary to develop a Smart-layer that will protect the optical fiber leads and will not significantly change the physical and mechanical characteristics. This paper aims to determine the stiffness and strength characteristics of samples made of polymer composite materials: reference samples, samples with embedded fiber-optic sensors, samples with embedded Smart-layers. In this work, a Smart-layer is understood as a coating that protects the fiber-optic sensors at the stage of implementation into a structure. The paper considers the following configurations of the Smart-layer: polymer reinforced mesh, polyamide and polyurethane layer. We analyzed and compared the influence of the embedded optical fiber and various configurations of the Smart-layer in the composite structure on the physicomechanical characteristics of the samples obtained under quasi-static loading (tension, compression, and interlayer shear). For a more detailed analysis of using the fiber-optic sensors and various configurations of the Smart-layer, the corresponding loads were simulated to assess their mechanical behavior. Based on the obtained physical and mechanical characteristics, a specific configuration of the Smart-layer was selected and justified for further researches.