Quality Of Surface Layer Research Articles

The Analysis Of Deterioration Of Village Road: A Case Of Palasah-Majalengka

Raising international issues related to road maintenance and repair. Road damage occurring in various countries, including cracks, potholes, and surface deformation, significantly impacts transportation safety and efficiency. Many roads in certain regions experience damage such as cracks, potholes, and surface deformation due to increased traffic loads and extreme weather conditions. The purpose of this paper is to analyze road damage in Karamat Village according to Bina Marga standards, to identify and understand the causes and effects of such damage. Primary data is the data collected from field observations at the study site, referred to as primary data or first-hand data. The road damage found on Pajaten road in Karamat Village, Majalengka Regency includes patches, cracks, disintegration, potholes, and waves. The purpose of routine maintenance is to improve the surface layer quality without increasing structural strength. The Pajaten road section in Karamat Village, Majalengka Regency, has conditions of loose stones, cracks, patches, potholes, and waves. The Directorate General of Highways states that the calculation results have a priority order of 10, placing it in the priority group > 7. According to Bina Marga, road damage is addressed through a routine maintenance schedule. Patching is the recommended and suggested method for repairing cracks, ruts, and collapses on roads.

Synthesizing vulnerability indices within a diverse lithological context: Corollaries for groundwater quality assurance and surface layer corrosiveness of Lokoja Geomaterials, Nigeria

ABSTRACT This study provides prototypical evaluation of groundwater vulnerability to contamination and soil corrosivity in Lokoja region, central Nigeria. By combining the aquifer vulnerability index, integrated electrical conductivity, groundwater confinement overlying strata depth to water table (GOD), and electrical anisotropy coefficient (λ) derived from lithological composition, resistivity, and layer thickness; the study identifies substantial vulnerabilities in the groundwater resources. Findings indicate that over 70% of the region is moderately to very highly vulnerable to groundwater pollution, especially in the eastern and southern parts, highlighting the need for tailored groundwater management strategies in highly vulnerable areas, covering 40% of the region. Corrosion potential varies spatially, with 80% of the upper layer being minimally corrosive and around 45% of the lower moisture-rich layer showing moderate to significant corrosiveness, emphasizing risks in central and northern zones associated with lithological compositions and moisture content. These accentuate the necessity of rigorous monitoring programs and strict land use regulations to protect aquifers and infrastructure. This research underscores the value of proactive management for safeguarding groundwater resources, providing an invaluable framework for decision-making and resource allocation to tackle contamination and corrosion risks. Importantly, the research addresses a significant research gap in a region with limited scientific exploration.

Evaluation of nanoparticle-enhanced silane and vinyl ester coatings for protecting concrete from ammonium sulfate

Inferior quality of concrete surface layers can lead to significant deterioration of concrete infrastructure due to the infiltration of fluids and deleterious substances from the surrounding environment. Concrete structures such as foundations, abutments, flatwork, and underground tanks in agricultural and mining zones, as well as slabs in factories producing ammonium-based fertilizers, are highly susceptible to ammonium sulfate attack, which is known as the most aggressive sulfate deterioration driven by acid-sulfate reactions. Coatings are an effective strategy for protecting such concrete structures to restore its performance and prolong its service life. Therefore, this study aimed at investigating the performance of nano-based coatings as superficial treatments for concrete elements exposed to aggravated exposures of ammonium sulfate. Silane (hydrophobic agent) and vinyl ester (membrane-forming polymer) were used as base resins, in which nano-clay and nano-calcium carbonate particulates were dispersed at different dosages (0, 2.5, and 5 %). In addition, a colloidal silica solution was used as a surface treatment. The durability of coated concrete specimens was evaluated under two ammonium sulfate exposures: full immersion and combined with cyclic environmental conditions (freezing-thawing and wetting-drying cycles). Degradation of concrete specimens was monitored by visual assessment and quantified in terms of mass and length changes over time. In addition, the deterioration mechanisms and coatings’ performance were studied by thermal, mineralogical, and microstructural tests. The results showed that colloidal silica could not adequately protect concrete specimens from these exposures. Conversely, silane nanocomposites improved the durability of concrete under both exposures and superior performance was generally observed for concrete specimens coated with vinyl ester nanocomposites.

A Simulation Study on Sieving as a Powder Deposition Method in Powder Bed Fusion Processes.

Powder deposition of even and homogeneous layers is a major aspect of every powder bed fusion process. Powder sieving is commonly performed to powder batches outside of the PBF machine, prior to the part manufacturing stage. In this work, sieving is examined as a method of powder deposition rather than a method to solely filter out agglomerates and oversized particles. Initially, a DEM powder model that has been validated experimentally is implemented, and the sieving process is modelled. The sieving process is optimized in order to maximize mass flow, duration of its linear stage and total mass sieved during linearity. For this, a Taguchi design of experiments with subsequent analysis of variance is deployed, proving that the larger the initial powder loaded in the sieve, the larger the sieve stimulation necessary, both in terms of oscillating frequency and amplitude. The sieve's aperture shape is also evaluated, proving that the more sides the canonical polygon has, the less the mass flow per aperture for the same maximum passing particle size. Then, the quality of the layer produced via controlled sieving is examined via certain layer quality criteria, such as the surface roughness, layer thickness deviation, surface coverage ratio and packing density. The findings prove that controlled sieving can outperform powder deposition via a non-vibrated doctor blade recoater, both in terms of layer surface quality and duration of layer deposition, as proven by surface skewness and kurtosis evaluation.

QUALITY AND CONTINUITY OF PLASMA PROCESSING OF THE TOP SURFACE LAYER OF THE REDUCER DRIVING SHAFT

The method of repairing and restoring machine parts by plasma flow is one of the most advanced methods. Based on this, the article explains the superior indicators of plasma processing of the worn upper surface layer of the drive shaft of the reducer. It is noted that the internal structure of the general reducer consists of a combination of details. It is said that the drive shaft is the main part of the reducer that is subjected to the greatest load during operation. And in connection with the diametrical inner surface of the gear wheel and the top surface of the drive shaft, these surfaces are subject to wear in the process of vibration during operation. It is noted that a certain restoration method should be carried out for the worn part of the upper surface layer of the drive shaft. And this method is carried out to increase the physical-mechanical properties of the upper surface layer of the drive shaft. The restoration of the upper surface layer of the part (drive shaft) by the plasma method is explained. The coating formed on the upper surface layer of the drive shaft of the reducer as a result of diffusion increases the service life of this shaft. It is called from the vacuum-ion plasma method. And as a general result, plasma processing has a positive effect on the quality and durability of the wearable top surface layer of the reducer drive shaft. It is noted that this processing method is effective for strengthening the worn upper surface layer of the drive shaft of the reducer. Keywords: drive shaft, top surface layer, plasma processing, strength, quality, continuity.

Применение ультразвука в процессе аддитивного производства пластиковых деталей

Despite huge prospects for the layer-by-layer synthesis of products, which makes it possible to produce parts of a unique shape, the widespread use of the method face the problems of making a proper microgeometry of the product surface, which due to the peculiarities of layer-by-layer production is rather rough, and mechanical methods of machine working often do not admit the possibility of figure-shaped parts post processing. The article studies the problem of ensuring the quality of the plastic parts surface layer obtained by additive technologies. For this purpose, it is proposed to use ultrasonic processing technologies. The existing methods of using ultrasonic vibrations in the production of plastic parts are analyzed: the manufacture of wire for 3D printing with additives, which results in an increase in the mechanical properties of the product. Besides, liquid treatment of a solvent-loaded product in order to remove supporting elements. Studies have been carried out on the finishing of parts in a solvent aerosol obtained by ultrasonic spraying. This method has a number of advantages in comparison with the treatment in solvent vapors obtained during its heating, which include the possibility of regulating the size of droplets, their moving speed, aerosol concentration, caused by changing the modes of ultrasonic treatment. As a result of experimental studies, it is found that the use of this treatment method eventuates an increase in the quality of the sample surfaces to be worked, and besides, it reduces the height parameters of roughness in the direction perpendicular to the layered growth of the product by more than a factor of ten. The mechanism of changing the microgeometry of the surface is as follows: when aerosol droplets contact the surface, part of the material forming the protrusions dissolves and fills valleys, while in the liquid state; after finishing the work, the material polymerizes, generating a surface with improved features.

The Impact of Heating Rate on the Kinetics of the Nitriding Process for 52100 Steel.

The aim of this study was to determine the impact of the heating rate of steel balls made of AISI 52100 alloy steel on the kinetics and efficiency of the gas nitriding process when carried out using a chemical reactor with precise thermo-gravimetric measurements, which allowed for changes in sample mass during heating and nitriding to be monitored with an accuracy of 50 µg. In the chemical reactor, the examined alloy steel was subjected to a heating process at the selected nitriding temperature of 590 °C. Two heating variants were used: the first variant relied on heating to the nitriding temperature with different rates-1 °C per minute, 2 °C per minute, 5 °C per minute and 10 °C per minute, respectively-whereas the second variant relied on the fast-25 °C per minute-heating of treated specimens to a temperature of 475 °C, at which, the nitrogenous potential of the atmosphere promotes faster nitrogen diffusion deep into the nitrided substrate, followed by reheating up to the nitriding temperature at different rates: 1 °C per minute, 2 °C per minute, 5 °C per minute, and 10 °C per minute, respectively. To evaluate the impact of heating rate kinetics and effectiveness during nitriding on the obtained surface layer quality, we investigated the phase composition, microhardness distribution, and thickness of the obtained diffusion layers. It was found that heating to a temperature of 475 °C in the nitriding process does not significantly affect the average mass gain of a sample. Above this temperature, within the range of nitriding temperatures, the extension of time increases the sample's mass gain. Simultaneously, it was found that the use of a constant heating rate allows for thicker nitrided layers and a greater sample hardness to be obtained. Dual-stage heating, in turn, is more effective in the context of sample mass gain per time unit.

Analysis of existing methods for improving the quality of surface layers

The article analyzes and classifies the main methods of improving the surface quality of friction pairs. The reliability of the machines is directly related to the quality of the surface layer, which is characterized by geometric and physico-mechanical parameters. The performance properties depend on the quality of the surface layer — wear resistance, corrosion resistance, contact fatigue resistance, etc. The paper presents a comparative analysis of the main methods of increasing the hardness of the surface.

Development of the structure and methodological support of the system for analysis of the details shaping using the technological inheritability of their quality parameters

Theoretical approaches, computer modell methods and experimental studies analyse the state and behaviour of machine parts to determine the changes in their properties and parameters from a single synergetic position. Development and implementation of integrated information systems for control of technological processes of manufacturing parts and machines assembly is an essential mover of the economic growth of industrialized countries. Complicating the operational conditions for the products increases the requirements for the parameters of their accuracy, surface layer quality, performance characteristics and reliability indicators. A mechanical engineering product is a technical system consisting of many subsystems and using the functionally-oriented design of technological processes planning for parts manufacturing. The structure and methodological providing of the PSPAS-system (Product Shaping / Processing Analysis System) investigates. PSPAS system includes the investigations of the technological inheritability of mechanical engineering product quality parameters combined with the analysis of traditional subsystems (cutting, surface plastic deformation, surface layer modification, assembly). Rheological simulation modelling, holding of experimental studies, the combination of mathematical modelling, theoretical and practical studies of technological processes ensure the implementation of the CAF system using the principle of functionally-oriented design during parts manufacturing and machines assembly.

Effect of drilling parameters on the hole surface integrity of low alloy steel for nuclear power during BTA deep hole drilling

Boring trepanning association (BTA) deep hole drilling is widely used in machining tube sheet of steam generator. In order to get a better service integrity, the surface quality after machining is required to be higher. In this paper, the effect mechanism of BTA deep hole drilling on the integrity and quality of the machined surface layer of low alloy steel SA508Gr.3Cl.2 for nuclear power is investigated. The results show that the gradient microstructure can be obtained by BTA drilling on the surface of the inner hole, including the recrystallized layer with grain refinement and the plastic deformation layer with high-density sub-crystal structure and grain distortion. With the increase of drilling speed and feed rate, the thickness of deformation layer increases. During the BTA deep hole drilling, the proportion of low-angle grain boundaries (LAGBs) increases with the increasing depth from the machined surface. The increase of drilling speed leads to the increase of recrystallization degree and the proportion of LAGBs in the machined surface. The effect of feed rate on the proportion of LAGBs is opposite. The machined surface is characterized by regular peak and valley, and there are typical surface defects mainly involving feed marks, surface tearing, and plowing grooves. With the increase of drilling speed, the surface roughness will decrease. The effect of feed rate on surface roughness is obviously lower than that of drilling speed. With the increase of drilling speed, and feed rate, the depth of hardened layer increases gradually, which is caused by dislocation strengthening and fine grain–strengthening effect during BTA drilling process. Higher drilling speed is recommended in forming a better machined surface with a strengthening layer of a certain thickness.

Investigation of microstructure of fretting wear behavior in 6061-T6 aluminum alloy

PurposeThe purpose of this study is to investigate the microstructure of fretting wear behavior in 6061-T6 aluminum alloy. The fretting wear of blind riveted lap joints of 6061-T6 aluminum alloy plates, which are widely used in aircraft construction, was investigated. Fretting damages were investigated between the contact surface of the plates and between the plate and the rivet contact surface.Design/methodology/approachExperiments were carried out using a computer controlled Instron testing machine with 200 kN static and 100 kN dynamic load capacity. Max package computer program was used for the control of the experiments. Fretting scars, width of wear scars, microstructure was investigated by metallographic techniques and scanning electron microscopy.FindingsIt was found that fretting damages were occurred between the plates contacting surface and between the plate and rivet contact surface. As load and cycles increased, fretting scars increased. Fretting wear initially begins with metal-to-metal contact. Then, the formed metallic wear particles are hardened by oxidation. These hard particles spread between surfaces, causing three-body fretting wear. Fretting wear surface width increases with increasing load and number of cycles.Originality/valueThe useful life of many tribological joints is limited by wear or deterioration of the fretting components due to fretting by oscillating relative displacements of the friction surfaces. Such displacements are caused by vibrations, reciprocating motion, periodic bending or twisting of the mating component, etc. Fretting also tangibly reduces the surface layer quality and produces increased surface roughness, micropits, subsurface microphone.

Technologies for Asphalt Pavement Surface Testing in Road and Bridge Construction

Asphalt pavement is currently one of the main components in the construction of roads and bridges. However, from a practical point of view, various quality problems are prone to occur in the surface layer of asphalt pavement, which will lead to the poor overall quality of road and bridge projects. Therefore, it should be applied reasonably. Advanced testing technologies are used to test the mixture quality, compaction, segregation, thickness, and other aspects of the asphalt pavement surface layer, so as to improve the quality of the asphalt pavement surface layer, and then improve the overall quality of road and bridge construction. Therefore, this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.

Specificity of the stress-strain and thermodynamic state simulation of the titanium alloy workpiece in the cutting zone

Titanium alloys have specific mechanical and physical-chemical properties that significantly reduce their machinability. Providing high productivity and accuracy has a great sense at the stage of technological preparation of machine-building production, taking into account the high cost of products from titanium alloys, as well as the need to provide increased operational properties. Simulation of machining processes of titanium alloys has many differences from the simulation of cutting of medium-carbon steels. This article focuses on recommendations for selecting an effective cutting model, describing the specific rheological properties of titanium alloys, optimizing solver selection, and cutting fracture criteria. The stages of adiabatic shear are described. The use of these recommendations contributes to the development of a more adequate model of machining titanium alloys and the choice of optimal cutting parameters to ensure a given quality of the machined surface layer of the workpiece.

Special features of the dynamic cutting process analysis in the machining of titanium alloys

The achievement of high accuracy parameters and the surface layer quality of the machined surface greatly depends on the dynamic stability of the system “Machine-Fixture-Tool-Workpiece”. It is especially important for machining titanium alloys because intensive tool vibrations are generated due to the adiabatic shear phenomenon. The causes and consequences of such effects are described in the article. The paper also describes a specific method for studying the dynamic state of the cutting system of titanium alloys, based on the system integration of the classical method of the analytical description of the vibration processes arising when machining and the method of rheological simulation of the cutting process. Two important problems are proposed to be solved for the effective analysis of the system modeling results: first, it is the filtering of the noise signal with preservation of the limiting values of modeling results and maximum sensitivity using the Savitsky-Golay mathematical apparatus; second, the problem of approximation and interpolation of the filtered function of cutting parameters by Fourier transform in time.

Anisotropic cutting mechanisms on the surface quality in ultra-precision machining of R-plane sapphire

The machined surface-layer quality of sapphire is influenced by its anisotropic properties. This work investigates the anisotropic cutting mechanisms on the surface quality of R-plane sapphire in ultra-precision machining. Plunge-cutting experiments were conducted to reveal ductile-to-brittle transition (DBT) depth. The groove topography and profiles show that the DBT depth with machining direction perpendicular to A-plane (type PER) can reach 200 nm, while the DBT depth with machining direction parallel to A-plane (type PAR) is <143.51 nm. However, the TEM images show a crack of 560 nm depth existing in the subsurface of type PER groove although its surface exhibits ductile characteristics. Besides, HRTEM results reveal that the dislocation defects determine the affected-layer depth for type PER groove, while the twinning defects dominate the affected-layer depth for type PAR groove. Moreover, overlap-cutting experiments highlight that the cutting force with type PER is larger than that with type PAR. MD simulation results indicate that the plastic deformation depth for type PER groove is higher than that for type PAR groove. In regards to the precision machining of sapphire, comprehensive evaluation of DBT depths, subsurface damage and cutting forces is essential for optimizing the process parameters.

Selected aspects of the design of special monolithic carbide milling cutters for austenitic steels

In many machining applications, the appropriate selection of cutting toolsin relation to the type of material being machined, the machining parametersand the required shape and dimensional accuracy is of particular importance.This especially applies to operations requiring the use of specific tools, i.e. toolsthat are not included in the standard offer but are tailor-made according tothe individual needs of the customer. The article focuses on the machiningproblems of selected austenitic grades of stainless steel and the selection oftechnologies (i.e. machining parameters and strategies and tool geometry)concerning the design and use of special monolithic carbide milling cutters.The possibilities of manufacturing elements from austenitic steels with highshape and dimensional accuracy and high surface layer quality are limited.Due to their high ductility, the tendency to create growths on the cutting edgeand the high compression strength coefficient, these materials pose a serioustechnological challenge. The analysis of phenomena presented in the articleforms the basis for developing guidelines for designing the machining processusing special monolithic carbide cutters dedicated for specific applications.

Evaluation of the influence of three-dimensional printing conditions on peel resistance and surface roughness of flexible polymer-textile composites

Extensive fashion and textiles research have adopted fused filament fabrication in three-dimensional printing. However, much research has dedicated itself to experimenting with rigid materials that lack the capability to mimic conventional textile-like garments. The commercialization of thermoplastic polyurethane/elastomers have posed greater potentials for developing flexible polymer-textile composites. Such materials will enable the creation of ergonomically designed textiles with optimized flexibility and elasticity aimed for garments. This study examines the influence of polymers, textile surface roughness, and nozzle temperature on peel resistance and polymer coefficient of friction/surface roughness. T-peel tests (ISO 11339:2022), cross-sectional microscopic image analysis, and a KES-FB4-A surface tester were used to evaluate the surface quality and peel resistance between polymer-textile assemblies. Our results revealed thermoplastic-polyurethane-knitted combinations to demonstrate superior peel resistance owing to knitted structure’s pore structure and thermoplastic polyurethane’s lower melting temperature. Moreover, a significant increase in peel strength was found at 260°C (above recommended printing temperature) in thermoplastic-polyurethane-knitted fabrics at 3.24 N/mm. While the coefficient of friction remained similar, a rougher surface quality was discovered at higher temperatures in thermoplastic polyurethane at 3.85 μm warp/4.35 μm weft. In thermoplastic elastomer, the roughest surface was found at 240°C measuring 3.65 μm warp/3.37 μm weft. This study fills a lack of research into flexible polymer-textile composites by suggesting parameters for achieving an equilibrium between optimal adhesion and polymer layer surface quality.

Development of a technological process for the restoration of piston pins using deforming broaching

The article discusses the technological process of restoring the geometric dimensional accuracy of piston pins of internal combustion engines (ICE) due to the expansion of the internal hole by a deforming element. As part of conducting research taking into account the resource of the used plasticity of the processed material, the processing modes are determined, the deformation scheme is selected and the geometry of the deforming element is calculated. The selection of the necessary deformation of the part during processing of the piston pin was carried out under the condition of compensating for wear and ensuring an allowance for subsequent mechanical processing. This made it possible to ensure the necessary processing quality of the pin hole surface layer according to the resource parameter of the used plasticity. The deformation scheme was chosen from the condition of ensuring the geometric accuracy of the pin outer surface, which determines the size and uniformity of the allowance for subsequent processing. For these reasons, a scheme was chosen in which the deformation is carried out by two elements with a change of the support end after the first pass. The optimal geometry of the deforming tool was determined from the standpoint of minimizing errors and preserving the initial length of the pin. The results of the conducted experiments showed that using selected expansion schemes, tensions and geometry of the deforming tool, made it possible to ensure the necessary allowance for the next mechanical processing, as well as the invariance of the part length after processing.

Technological Methods of Ensuring the Reliability of Lock Connections in Marine Gas Turbines

Abstract The article presents the test results of the surface quality parameters after broaching of heat-resistant steels of grades: 1.7335 (13CrMo4-5) and 1.4841 (X15CrNiSi25-20). The aim of the work is to determine the technological methods of obtaining the lowest treated surface roughness, surface layer hardening and the elimination of surface defects after broaching. To investigate the influence of cutting conditions (cutting speed, tool geometry and feed) on surface roughness and hardness, the physical modeling method of the broaching was used. As a result of the research, recommendations for improvement of the main parameters of the surface layer quality when broaching samples from selected grades of heat-resistant steels.

Flow Field Measurements Of The Grinding Cooling Liquid Jet

The workpiece cooling by metalworking fluids, which has a significant influence on the workpiece surface layer quality, is not fully understood for industrial grinding processes. This necessitates a significant effort in determining optimal cooling conditions empirically, raising part manufacturing costs. As a solution, a measurement method for the metalworking fluid flow field near the grinding wheel is desired to close the knowledge gap. However, the fluctuating curved surfaces of the coolant cause unpredictable light deflections and reflections, making optical flow measurements difficult. To evaluate the effect of light deflections on the coolant flow measurements, particle image velocimetry is applied in combination with background-oriented schlieren and a ray-tracing approach. Here we study coolant flow measurements in a grinding machine for in-process supply conditions, at first without a working piece and with a focus on the measurability and reliability of the coolant flow from the nozzle exit to the interaction with the rotating grinding wheel. As a result, for the nozzle flow, a systematic measurement deviation of up to 2 % is identified and after the correction, a plausible flow behaviour is obtained. Furthermore, the in-situ measurements of the coolant flow in interaction with the grinding wheel reveal a detailed description of the fluid-workpiece interaction.