Cutting & Tools in Technological System

FORM ACCURACY AND CUTTING FORCES IN TURNING OF X5CRNI18-10 SHAFTS: A STUDY ON CYLINDRICITY, COAXIALITY, STRAIGHTNESS, AND WAVINESS AT SMALL FEEDS

2025-06-18T09:39:36+03:00

This paper investigates how the cutting speed (vc), feed rate (f) and depth of cut affects the cutting forces and the quality of the surface during turning operations. For the study different experiments have been performed at two depths of cut (0.5 mm and 1.0 mm) to observe how they affect the cutting force, cylindricity, coaxiality (COAX DIN), straightness and waviness. From the results it can be said that the cutting forces and surface deviations increase with the increase in depth of cut. Cutting force normally brings down the forces and enhances surface quality but feed rate has exactly opposite impact. Thus, it is necessary to choose parameters wisely to keep machining efficiency and dimensional accuracy in balance.

COMPUTATIONAL AND ANALYTICAL MODELS OF THE MAJOR TYPES OF CUTTING TOOL FAILURE

2025-05-29T12:43:57+03:00

The paper presents analytical and numerical models for assessing the reliability of cutting tools used in the processing of critical parts for the defence and energy industries. The criteria of boundary wear on the back and front surfaces, possible fatigue failure and plastic deformation of the cutting edge are taken into account. Analytical dependencies have been constructed to calculate the number of parts that can be machined before tool failure, taking into account the physical and mechanical characteristics of the tool and processed materials, technological modes and thermal loading conditions. The results allow for the selection of tools and cutting parameters based on increased reliability and process optimisation. These mathematical dependencies make it possible to take into account the predominant type of cutting tool wear, which is especially important when working with large parts on heavy machine tools. The results of the study are of practical importance for industry, as they allow to increase the stability and productivity of technological processes.

MODELING THE IMPACT OF NONLINEAR OSCILLATIONS ON THE QUALITY OF THE WORKING SURFACE OF PARTS IN FINISHING OPERATIONS

2025-05-28T12:07:13+03:00

The paper investigates the influence of finishing operations on the roughness of machined surfaces in the case when the machine-tool-fixture-tool-part (MTFTP) system is in the zone of nonlinear oscillations. For this purpose, models of dynamic oscillatory processes accompanying the machining of working surfaces of parts are built in the Simulink system of the MATLAB package. The formation of self-excited oscillations of the MTFTP mechanical system during finishing operations is determined with one or two degrees of freedom associated with the heterogeneity of the processed material and external disturbing forces in the ranges of fundamental and subharmonic resonances containing, in addition to the excitatory element itself, also zones of dry friction of the tool with the processed surface. These studies not only demonstrate the behavior of mechanical systems capable of self-excited oscillations, but also allow their results to be successfully applied to optimize the quality characteristics of machined surfaces during finishing operations. It has been shown that resonant curves under nonlinear oscillations of mechanical systems of finishing operations affect not only the formation of the roughness of the machined surface, but also the appearance of scorch marks on them and the formation of defects such as cracks.

CUTTING FORCE DISTRIBUTION IN TANGENTIAL TURNING OF 42CRMO4 ALLOY STEEL: INFLUENCE OF HIGH CUTTING SPEEDS AND HIGH FEED RATES

2025-06-18T11:12:28+03:00

This study investigates the cutting force distribution during tangential turning of 42CrMo4 alloy steel under high cutting speeds and high feed rates. The experiments were conducted by varying cutting speed (200 and 250 m/min), feed rate (0.3 and 0.8 mm/rev), and depth of cut (0.1 and 0.2 mm). The major cutting force, feed directional force, and thrust force components were measured, and their maximum values and relative ratios were analysed. The results indicate that both cutting speed and feed rate have a significant influence on the magnitude and distribution of the cutting force components. Higher cutting speeds generally led to a reduction in cutting force values, while increased feed rates resulted in higher force magnitudes and altered force ratios. The obtained data contribute to a better understanding of the cutting mechanics in tangential turning, supporting process optimization and the selection of appropriate cutting parameters for improved machining performance.

CARBON DIOXIDE EMISSIONS AND SURFACE ROUGHNESS ANALYSIS DURING DIAMOND BURNISHING

2025-06-18T08:54:17+03:00

Carbon emissions are one of the most pressing environmental problems of our time. CO2 emitted by human activities, especially industry, transport and energy production, is a major contributor to the gradual warming of the Earth's atmosphere. The aim of my research is to investigate the relationship between carbon dioxide emissions and surface roughness by varying different technological parameters during diamond burnishing. In the first chapter of this paper, we will review the current state of the art and literature on carbon dioxide emissions and then, based on a chosen methodology, we will show how carbon dioxide emissions from diamond polishing can be quantified. Following the calculation, we will present the technological parameters used for the machining, the test pieces on which we measured surface roughness after diamond burnishing, and some additional calculations needed to evaluate the data. In the main part of the research, we will evaluate the calculated data using 2D and 3D surface roughness metrics, with a special focus on the characteristics of the Abbott-Firestone curve.

ANALYSIS OF PARAMETERS OF LASER-INDUCED PERIODIC MICROSTRUCTURES (LIPSS) ON THE SURFACE OF STAINLESS STEEL USING AUTOCORRELATION FUNCTIONS

2025-05-28T16:55:13+03:00

In modern mechanical engineering, the control of surface quality of components, which directly affects their operational characteristics, is becoming increasingly important. One of the key aspects is the analysis of surface microstructure, particularly its periodicity, as it determines properties such as wear resistance and corrosion resistance. Laser processing is one of the promising technologies that allows the formation of regular microstructures, such as LIPSS (Laser-Induced Periodic Surface Structures). Despite extensive research, the mechanism of LIPSS formation remains not fully understood, and the results often show variable periodicity and orientation. To accurately analyze these structures, mathematical and statistical methods, such as two-dimensional autocorrelation analysis (ACF) and fast Fourier transform (FFT), are required. This study proposes a methodology for evaluating the periodicity of microstructures obtained during laser treatment of metallic samples, using digital video microscopy. The application of two-dimensional autocorrelation and spectral analysis within the Gwyddion environment ensures reproducible and objective assessment of microstructures, while demonstrating the effectiveness of ACF for surface topography analysis. The obtained data show the presence of pronounced periodicity in the studied microstructure and confirm the complexity of the LIPSS formation mechanisms, contributing to accurate quantitative analysis and adaptive control of laser modification processes.

CURRENT RESEARCH IN THE DEVELOPMENT OF TREATMENT AND POLISHING TECHNOLOGIES TO OBTAIN HIGH-QUALITY SURFACES (REVIEW)

2025-05-27T18:38:55+03:00

Modern research indicates the effectiveness of using abrasive and chemical-mechanical methods in polishing, taking into account the characteristics of the abrasives used. At the same time, for chemical-mechanical polishing (CMP), researchers consider two directions: the influence of different abrasives, i.e., emphasis on the mechanical component of CMP, and the influence of suspension, i.e., emphasis on the chemical component. As an abrasive for polishing, diamonds are used in the tool in the form of metallic Cu6Sn5 and polymer diamond film overlays, as well as with the use of a mixed abrasive suspension of cerium and diamond. The features of polishing Al2O3–SiO2 with mixed particles and pure – SiO2, as well as new abrasives of the core-shell type SiO2@A-TiO2 are separately considered. In new suspensions containing Fe, Al2O3, a new material is added - graphene oxide (GO), and deionized water is also used in CMP, and this is a certain modern research trend.

PREDICTION OF RESIDUAL DEFORMATIONS IN PRODUCTS MANUFACTURED BY SELECTIVE LASER SINTERING

2025-05-31T18:37:55+03:00

This study addresses the critical challenge of predicting residual deformations in industrial products manufactured using selective laser sintering (SLS) technology. Residual deformations represent one of the primary factors leading to geometric inaccuracies in SLS-produced parts, directly affecting their functional performance and dimensional precision. The research proposes and validates a novel hypothesis that existing prediction models developed for plastic injection molding can be effectively adapted for SLS applications through appropriate conversion factors. Given the absence of specialized tools for SLS deformation prediction in the current market, this approach leverages the mature capabilities of the SOLIDWORKS Plastics software as an alternative solution. The methodology involves creating finite element models of test components, specifying material properties similar to SLS powders, and simulating thermal conditions that mimic the SLS process. Through a comparative analysis of twelve distinct geometries, a significant correlation between predicted deformations and actual measured deformations was established. This coefficient enables reliable translation between simulation results and actual SLS outcomes. The findings demonstrate that technological compensating deformations can be effectively calculated and applied to original triangulation models, substantially reducing geometric deviations in final products. The research bridges the gap between established injection molding simulation techniques and the rapidly evolving field of additive manufacturing, providing a practical approach to enhance dimensional accuracy without requiring specialized SLS deformation prediction software. This research was developed at the Department of "Integrated Technologies of Mechanical Engineering" named after M. Semko of NTU "KhPI".

MECHANICAL BEHAVIOR PREDICTION OF CARBON FIBER-REINFORCED ONYX IN FDM USING INTEGRATED STATISTICAL AND MACHINE LEARNING APPROACHES

2025-05-30T19:38:59+03:00

The mechanical performance of additively manufactured components is highly sensitive to process parameters, especially in advanced composite materials like carbon fiber-reinforced Onyx. This study presents a comparative optimization framework combining Response Surface Methodology (RSM) and machine learning (ML) to model and enhance the tensile and flexural strengths of Fused Deposition Modeling (FDM) printed Onyx composites. Key parameters including infill pattern, infill density, and nozzle temperature—were systematically varied using a Taguchi L9 design, and mechanical testing was performed according to ASTM standards. Statistical analysis revealed infill pattern as the most significant factor affecting strength properties. RSM provided reliable predictions with R² values of 97.61% (tensile) and 95.93% (flexural), while ML models, particularly XGBoost coupled with Bayesian optimization, achieved superior prediction accuracy with zero average error. Both methods converged on the same optimal parameters hexagonal infill, 60% infill density, and 265 °C nozzle temperature highlighting the consistency and robustness of the integrated approach. The results demonstrate that combining traditional statistical methods with advanced machine learning offers a powerful pathway for precise process control and mechanical optimization in polymer composite additive manufacturing.

GEOMETRICAL ACCURACY OF CONCRETE WALLS MANUFACTURED BY 3D PRINTING

2025-06-20T10:28:44+03:00

The presented results were obtained during a theoretical and experimental study of the geometric accuracy and surface quality parameters of concrete walls manufactured using additive technologies. Theoretical aspects of the classification of defects and deviations of surfaces obtained by layered concrete construction have been developed. The study examines the influence of layer thickness on printing precision and defect formation in 3D concrete printing (3DCP) processes. Two experimental samples were fabricated with different layer thicknesses: 20 mm and 15 mm. Systematic measurements were conducted to evaluate crack depth on vertical surfaces, pore depth on horizontal surfaces, track width variations, and deviations from straight-line geometry. The experimental methodology involved comprehensive measurement protocols using precision instruments to assess geometrical parameters and surface quality characteristics. Statistical analysis was performed to quantify the relationships between layer thickness and printing accuracy, including calculations of mean values, standard deviations, and coefficients of variation for all measured parameters. Results demonstrate significant improvements in geometrical accuracy when reducing layer thickness from 20 mm to 15 mm. Crack depth on vertical surfaces decreased by 56%, while deviations from straight-line geometry improved by 32%. Most notably, track width stability showed a remarkable enhancement, with the coefficient of variation improving by 91%, indicating substantially improved process repeatability. The 15 mm layer thickness configuration exhibited superior performance across all measured parameters, demonstrating enhanced layer adhesion, reduced surface defects, and improved dimensional consistency. The coefficient of variation for crack depth decreased from 43% to 24%, while deviation variability reduced from 32% to 12%, confirming improved process control and predictability. These findings provide valuable insights for optimizing 3D concrete printing parameters and establishing quality control protocols for additive construction applications. The research contributes to the development of standardized practices for concrete 3D printing technology and demonstrates the critical importance of layer thickness optimization for achieving high-quality printed concrete structures. The results confirm the effectiveness of implementing thinner layers, given the increased requirements for geometric accuracy and surface quality in automated concrete construction processes. This research was conducted at "Geopolimer" LTD to implement innovative technologies in the construction industry.