Wyniki wyszukiwania - BazTech

1

Investigation of the effects of machining parameters on cutting conditions during orthogonal turning of austenite stainless steel

Kónya Gábor, Takács János, Miskolczi István, Kovács Zsolt F.

Production Engineering Archives

|

2024

|

Vol. 30, Iss. 1

86--93

EN

The 1.4306 austenite stainless steel has been prominently utilized as a material in the automotive and aerospace industry. Considerable interest has been garnered in the machinability of stainless steel owing to its high strength and poor thermal conductivity. The aim of this study is to ascertain the influential cutting parameters, specifically the cutting speed and feed rate, on cut-ting forces, cutting temperature, and chip evaluation. Thus, austenite stainless steel was subjected to free-cutting using a carbide recessing tool under dry conditions. The principle of measuring cutting temperature, a complex procedure due to varying thermal homogeneity, was elucidated. For the turning experiments in question, the standard Taguchi orthogonal array L9 (32 ), featuring two factors and three levels, was employed. The experimental results were analyzed using MiniTab 17 software. The findings reveal a substantial effect of feed rate on cutting force, cutting temperature, and chip evaluation. The highest cutting force and cutting temperature were observed at a feed rate of 0.15 mm/rev. Conversely, the cutting force was minimized at a cutting speed of 100 m/min, indicating potential for increasing the cutting speed. The augmentation of feed rate led to chip compression and discoloration, attributed to elevated cutting force and a larger chip cross-section that efficiently dissipates heat from the cutting zone

2

Machinability of steels used for drinking water installation fittings

Chaczyk Agnieszka, Skoda Philipp, Krawczyk Janusz

Inżynieria Materiałowa

|

2024

|

Vol. 45, nr 1

6--11

EN

The machinability of two steels was assessed: 11SMnPb37 with reduced lead content and lead-free 11SMn30 steel. Turning tests were performed based on the selection of parameters, as a result of which the tool will be worn after 1 minute. The evaluation took into account power consumption, chip shape, changes in the surface layer and surface roughness. The tests are aimed at determining the own index of machinability of materials used in SANHA Polska. The generally available machinability index has to be adapted to each application [1]. This adaption is often pretty time and cost consuming. Therefor we are looking for a fast and cheap alternative for the rich machine park with various machining properties. The developed methodology and the obtained results are the basis for further research conducted as part of the implementation doctorate, the aim of which is to implement the production of well-machinable lead-free materials for drinking water installation, characterized by good solderability and corrosion resistance.

PL

Przeprowadzono ocenę skrawalności dwóch stali: 11SMnPb37 z obniżoną zawartością ołowiu i bezołowiowej stali 11SMn30. Próby toczenia wykonano w oparciu o dobór parametrów, w wyniku których narzędzie zostało zużyte po czasie 1 min. Przy ocenie wzięto pod uwagę pobór mocy, kształt wióra, zmiany w warstwie wierzchniej materiału i chropowatość powierzchni. Badania miały na celu wyznaczenie własnego indeksu skrawalności materiałów stosowanych w SANHA Polska. Ogólnie dostępny wskaźnik skrawalności musi być dostosowany do danego zastosowania [1]. Taka adaptacja jest często dość czasochłonna i kosztowna. Dlatego przeprowadzono 1-minutowy test jako szybką i tanią alternatywę dla bogatego parku maszynowego o różnych właściwościach obróbczych. Opracowana metodyka i otrzymane wyniki stanowią podstawę do dalszych badań prowadzonych w ramach doktoratu wdrożeniowego, którego celem jest wdrożenie do produkcji dobrze skrawalnych materiałów bezołowiowych przeznaczonych do instalacji wody pitnej, charakteryzujących się dobrą lutownością i odpornością na korozję.

3

Influence of Aluminium Oxide Nanoparticles Mass Concentrations on the Tool Wear Values During Turning of Titanium Alloy Under Minimum Quantity Lubrication Conditions

Szczotkarz Natalia, Adamczuk Krzysztof, Dębowski Daniel, Gupta Munish Kumar

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no 1

76--88

EN

Recently, environmental consciousness has led to the quest for ways to minimise negative elements in machining operations that threaten operator health and the environment. Titanium alloys are hard to cut, thus cooling the cutting zone is essential to reduce tool wear. Variations in Al2O3 nanoparticle concentrations supplied to the MQL cutting fluid affect cutting wedge wear during Ti6Al4V alloy turning. A diameter of 15 nm nanoparticles were utilised at 0.25, 0.5, 0.75, and 1 wt% mass concentrations. In the experiments, the flank face wear band width VBB and crater width KB were measured. Comparisons were also made using dry-cutting tools and the MQL approach without nanoparticles. X-ray microanalysis was used to quantify and qualitatively assess the chemical composition of chosen rake surface micro-areas. Studies showed that Al2O3 nanoparticle mass concentration affects tool wear when turning a hard-to-cut alloy. 0.5 and 0.75 wt% mass concentrations had the lowest flank and rake wear of the four mass concentrations. The SEM examination showed that 0.5 wt% mass concentration decreased adhesive wear the most.

4

A review on machinability in the milling processes

Demirpolat Havva, Kuntoğlu Mustafa, Binali Rüstem

Sustainable Production, Instrumentation and Engineering Sciences

|

2023

|

vol. 1, nr 1

27--36

EN

This review paper focuses on the up-to-date machinability characteristics of milling processes such as cutting forces, surface roughness and tool wear and their impacts on the cutting mechanism. The methodology pur-sued in this paper is to analyze the previous research articles published between 2019–2022 classifying them into the subcategoriesthat usemill-ing operation as manufacturing strategy. As known, milling is one of the most used machining processes in industry and often applied for academic studiesforawide range of materials. Therefore, used sensor systems, main aim and the preferred methodology were summarized in the context of this paper. Seemingly, a great number of machinability papers have been published recently which focuses on the several types of engineering ma-terials and utilized various types of sensor system to improve the surface roughness and tool life. In addition, the investigation showed that optimi-zation approaches have been applied broadly to detect the best machining conditions. Also, it was observed that several modeling approaches such as finite element analysis is a good alternative to analyze the process.

5

A comparative study of CNN, LSTM, BiLSTM, AND GRU architectures for tool wear prediction in milling processes

Zegarra Fabio C., Vargas-Machuca Juan, Coronado Alberto M.

Journal of Machine Engineering

|

2023

|

Vol. 23, No. 4

122--136

EN

Accurately predicting machine tool wear requires models capable of capturing complex, nonlinear interactions in multivariate time series inputs. Recurrent neural networks (RNNs) are well-suited to this task, owing to their memory mechanisms and capacity to construct highly complex models. In particular, LSTM, BiLSTM, and GRU architectures have shown promise in wear prediction. This study demonstrates that RNNs can automatically extract relevant information from time series data, resulting in highly precise wear models with minimal feature engineering. Notably, this approach avoids the need for excessively large window sizes of data points during model training, which would increase model complexity and processing time. Instead, this study proposes a procedure that achieves low prediction errors with window sizes as small as 100 data points. By employing Bayesian hyperparameter optimization and two preprocessing techniques (detrend and offset), RMSE errors consistently fall below 10. A key difference in this study is the use of boxplots to provide a better representation of result variability, as opposed to solely reporting the best values. The proposed approach matches more complex state of-the-art. methods and offers a powerful tool for wear prediction in engineering applications.

6

Advances in friction stir welding of Ti6Al4V alloy complex geometries: T-butt joint with complete penetration

Ambrosio Danilo, Wagner Vincent, Vivas Javier, Dessein Gilles, Aldanondo Egoitz, Cahuc Olivier

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 3

art. no. e182, 2023

EN

In this work, the friction stir weldability of Ti6Al4V T-joints has been investigated. Its aims are: (i) to study the influence of tool and welding parameters on weld quality, (ii) to assess the joints’ mechanical strength to foresee future applications, and (iii) to characterize Co-based FSW tools’ wear by following the wear during the tests. Welds’ defectivity is studied by cross-section macrographies analysis. Independently from welding parameters and tools, internal voids are avoided, and a suitable weldability window is identified. Microstructure observations have corroborated temperatures below the -transus point even in the nugget zone, guaranteeing joints’ maximum mechanical strengths at 96% and 87% of the base material for UTS and Y, respectively. Contrarily, elongation at break is very low, without reaching 20% of the base material. The failure is linked to section thinning and kissing bond defects at the joints’ corners. Additionally, tool wear proved to be a critical issue while friction stir welding Ti6Al4V. The inner part of the shoulder is the most sensitive to wear. The consequent high wear rate might be a problem for mass production. The work established the pertinence of assembling complex geometries of Ti6Al4V using friction stir welding, considering weld quality and the mechanical strength achieved. However, critical factors such as section thinning, kissing bond, and tool wear must be carefully addressed to avoid joints’ low elongation at break and to guarantee their mechanical strength.

7

Determination of twist drill bits wear: the effect of the composition and structure of the steels

Prałat Karol, Krupińska Andżelika, Ochowiak Marek, Włodarczak Sylwia, Matuszak Magdalena, Ciemnicka Justyna, Koper Artur, Wójcicka Karolina

Polish Journal of Chemical Technology

|

2022

|

Vol. 24, nr 3

8--13

EN

The aim of the study was to relate the infl uence of the chemical composition, structure, and basic properties as hardness of the tested drill bits on resistance to their wear. The chemical composition of the drill bit was investigated using the electric excitation emission spectrometry method and EDS microanalysis. Metallographic specimens were prepared and observed to determine the structure of each tool. Hardness tests were carried out on the shank and the working part of the tools. Material wear tests were carried out on the basis of measuring the wear of the drill bit flank. It has been shown that the appropriate selection of the chemical composition and heat treatment has a signifi cant impact on the wear resistance of cutting tools, which directly translates into their quality.

8

Progress in structured and textured cutting tools. Part 2. Influence of structured and textured cutting tools on the process performance

Grzesik Wit

Mechanik

|

2022

|

R. 95, nr 7

6--10

EN

This paper presents the possible influence of structured and textured cutting tools made of different cutting tool materials. Some recently published data concerning research works in the influence on the cutting mechanics (componential cutting forces and chip formation mechanism), heat generation and transfer, interface contact conditions and lubrication, interface friction and tool wear are discussed.

PL

W artykule przedstawiono możliwy wpływ strukturyzowanych i teksturyzowanych ostrzy skrawających wykonanych z różnych materiałów narzędziowych na przebieg procesu skrawania. Omówiono wnioski z ostatnio opublikowanych prac badawczych na temat czynników mających wpływ na mechanikę procesu (składowych siły skrawania i procesu tworzenia wiórów), generowania oraz rozpływu ciepła, warunków kontaktu i smarowania, tarcia i zużycia ostrza.

9

Material dynamic behavior in cutting zone of Inconel 718 and its infuence on cutting process

Hao Zhaopeng, Cheng Gang, Li JiNing, Fan Yihang

Archives of Civil and Mechanical Engineering

|

2022

|

Vol. 22, no. 3

art. no. e146

EN

The nickel-based superalloy Inconel 718 is widely used in aerospace and other fields due to its excellent performance. However, the alloy elements are presented in the form of compounds with high hardness, such as TiC, NbC, MoC, TiN and so on, which lead to complex cutting deformation in machining Inconel 718. In this study, the cutting experiments and the fast tool-drop test were carried out to obtain the chip root. Combining the split Hopkins pressure bar (SHPB) test, a scanning electron microscope (SEM) was used to observe the metallographic micrographs of the specimens and analyzed the plastic dynamic behavior of the material in the cutting area. The soft and hardening mechanism in the dynamic deformation process was described. The stress distribution model of material in the cutting area was proposed and the influence of stress distribution on cutting deformation, side fow and tool wear during the cutting process were also given.

10

Wear and surface characteristics on tool performance with CVD coating of Al2O3/TiCN inserts during machining of Inconel 718 alloys

Agari Shailesh Rao

Archive of Mechanical Engineering

|

2022

|

LXIX, nr 1

59--75

EN

The Inconel 718 alloys, which are primarily temperature resistant, are widely used in aviation, aerospace and nuclear industries. The study on dry cutting processes for this alloy becomes difficult due to its high hardness and low thermal conductivity, wherein, most of the heat transfers due to friction are accumulated over the tool surface. Further, several challenges like increased cutting force, developing high temperature and rapid tool wear are observed during its machining process. To overcome these, the coated tool inserts are used for machining the superalloys. In the present work, the cemented carbide tool is coated with chemical vapor deposition multi-layering Al 2O 3/TiCN under the dry cutting environment. The machining processes are carried out with varying cutting speeds: 65, 81, 95, and 106 m/min, feed rate 0.1 mm/rev, and depth of cut 0.2 mm. The variation in the cutting speeds can attain high temperatures, which may activate built-up-edge development which leads to extensive tool wear. In this context, the detailed chip morphology and its detailed analysis are carried out initially to understand the machining performance. Simultaneously, the surface roughness of the machined surface is studied for a clear understanding of the machining process. The potential tool wear mechanism in terms of abrasion, adhesion, tool chip off, delaminating of coating, flank wear, and crater wear is extensively identified during the processes. From the results, it is observed that the machining process at 81 m/min corresponds to a better machining process in terms of lesser cutting force, lower cutting temperature, better surface finish, and reduced tool wear than the other machining processes.

11

Testing of Air-Cooling Efficiency of the Underside of a Turning Tool Carbide Insert in EN-GJL 250 Cast Iron Turning Operations

Bartoszuk Marian, Prażmowski Mariusz, Hurey Igor

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 4

1--9

EN

This article shows the results of research on the effectiveness of operation of an original tool air cooling system in cutting. A case of turning EN-GJL 250 cast iron with TH10 tungsten carbide cutting inserts without protective coatings was selected for testing. The paper gives constructional details of the tested tool cooling system and discusses the principle of its operation. The research carried out has shown that this way of cooling the cutting insert causes a significant decrease in temperature in all sub-areas of the cutting zone. In addition, air cooling has been proven to significantly reduce cutting tool wear and slightly improve the roughness of the machined surface. The results obtained showed that the proposed method of cooling can be successfully used in the treatment of grey cast iron. In the future, it may serve as a basis for the construction of a professional cooling system for industrial applications.

12

Cutting Mechanics when Turning Powder Metallurgy Produced Nickel-Cobalt Base Alloy with a Cubic Boron Nitride Insert

Daź Waldemar, Habrat Witold, Tymczyszyn Jarosław, Krupa Krzysztof

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 4

163--175

EN

For the critical aero-engine parts it’s important to understand influence of cutting tools, cutting parameters, tool ware etc. on near surface condition which highly affect fatigue strength and at the same part life-time. New material implemented for the latest designs of aero-engines parts generate challenges for machining processes to fulfil strict requirements of aviation standards. Finish machining is the most important stage of process influencing fatigue strength. cBN tool are often used for final stage of machining. The objective of this study was analysis of cutting mechanics during finish turning of modern nickel-cobalt based alloy with cBN insert. Observations of cutting tool wear and cutting parameters influence on the components of cutting force, surface roughness and residual stress are presented in this paper.

13

Analysis of the compromise between cutting tool life, productivity and roughness during turning of C45 hardened steel

Abidi Youcef

Production Engineering Archives

|

2021

|

Vol. 27, Iss. 1

30--35

EN

Tool wear and surface roughness as performance indexes are considered to be the most important in terms of hardened materials’ machinability. The best combination of cutting parameters which enhances the compromise between tool life, productivity and machined surface quality contribute to benefice on production cost, which makes manufacturing industry interested in it. The aim of this research is to investigate the life of ceramic cutting tool and machining productivity together with surface roughness during turning of hardened steel C45, with focus on the selection of the optimal cutting parameter combination. The experiments are carried out based on uni-factorial planning methodology of cutting speeds and feed rates. The results show that the mixed ceramic tool is suitable for turning hardened steel C45 (40 HRC) and the conclusion is that it performed well in terms of tool life, productivity and surface quality at a combination of cutting speed (200 m/min), feed (0.08 mm/rev) and depth of cut (0.3 mm). Additionally, a tool life model has been proposed which is presented very high coefficient of determination.

14

A review of the recent investigations regarding texturized cutting tools

Jarosz Krzysztof

Mechanik

|

2021

|

R. 94, nr 4

6--9

EN

This paper presents some important, recently performed investigations on the laser texturing technology applied to the PCD and PCBN cutting tools and some resulting process outputs including cutting forces, tool wear indexes concerning both rake and flank tool faces. It was documented that the properly texturized tool faces results in a substantial reduction of cutting forces, elimination of the adhesion interaction between the tool and the chip, and reduction of abrasive and diffusion tool wear. The role of additional lubrication supply to the cutting zone with modified contact properties is discussed.

PL

W artykule przedstawiono kilka ważnych, niedawno przeprowadzonych badań nad technologią teksturowania laserowego zastosowaną w narzędziach skrawających z PCD i PCBN oraz niektóre wynikające z tego procesu wyniki odnośnie do siły skrawania, wskaźników zużycia narzędzia, dotyczące zarówno powierzchni natarcia, jak i powierzchni bocznej narzędzia. Udokumentowano, że odpowiednio teksturowane powierzchnie narzędzi powodują znaczne zmniejszenie sił skrawania, eliminację interakcji adhezyjnej między narzędziem a wiórem oraz zmniejszenie zużycia ściernego i dyfuzyjnego narzędzia. Omówiono rolę dodatkowego doprowadzania smaru do strefy skrawania o zmodyfikowanych właściwościach stykowych.

15

New method for determining single cutting edge breakage of a multi-tooth milling tool based on acceleration measurements of an instrumented tool holder

Ramsauer Christoph, Bleicher Friedrich

Journal of Machine Engineering

|

2021

|

Vol. 21, No. 1

67--77

EN

In machining applications predominantly for automated machining cells, tool life is often not used to its full extend and cutting tools are exchanged prematurely to avoid tool breakage and thus machine downtime or even damage at work piece or machine. Both effective process monitoring and adequate process control require reliable data from sensors and derived indicators that enable meaningful evaluation. Acceleration measurement by the instrumented tool holder provides signals with high quality from close to the cutting zone. Using the monitoring system, the gained data of the instrumented tool holder can be analyzed especially for the use case of unexpected tool wear, chipping of the cutting edge or breakouts at end mills. This paper describes the data analysis based on the rotational sensor and the corresponding effects on the measurement, an advanced assessment of the spectral distribution in the frequency domain and the experimental results of a test series.

16

Investigation of notch wear mechanisms in the machining of nickel-based Inconel 718 alloy

Grzesik Wit

Journal of Machine Engineering

|

2021

|

Vol. 21, No. 1

56--66

EN

This paper highlights tool wear mechanisms in the machining of heat resistance alloys including nickel-based Inconel 718 alloy which is one of the most popular material in the aircraft industry. Special attention was paid to the notch wear which develops on the flank face due to high temperature oxidation of the cutting tool material at temperature of about 800°C. The experimental procedure includes the diffusion couple methods and tool wear tests which assess the degradation of the deposited coating. The obtained results were supported by SEM images of the flank face periphery and EDS analysis performed in the regions of intensive oxidation. Some conclusions and ongoing research on the investigation of the oxidation phenomenon of cutting tool materials are outlined.

17

Correlation analysis between tool wear, roughness and cutting vibration in turning of hardened steel

Abidi Youcef, Boulanouar Lakhdar

Engineering Transactions

|

2021

|

Vol. 69, iss. 4

403--421

EN

Hard machining is a process that has become highly recommended for replacing grinding in the manufacturing industry. This is due to its ability to machine complex shapes with reduced production costs by reducing the machining time and being an ecological process. Three technological parameters determine the quality and productivity generated from this process: cutting vibration, surface roughness and tool wear. Therefore, the analysis of the correlation between them is very important. In the present investigation, the analysis of the correlation between cutting vibration, surface roughness and tool wear during a dry machining of hardened steel with a mixed ceramic tool is conducted in order to control these parameters online. This analysis is validated by developing predictive mathematical models. To neutralize the effect of cutting parameters, a combination of parameters such as cutting speed, feed rate and depth of cut to be used in the experimental tests is selected from the literature based on a quality-productivity optimum performance. In the early stage, the effect of machining time on the three technological parameters is studied, then assessed by developing predictive mathematical models. In the second stage, an experimental and statistical analyses such as the Pearson and Spearman correlation methods are employed to determine correlations between tool wear, surface roughness and cutting vibration. Each parameter is compared with the other two. The models and their validations are developed using the Minitab 16 tool, and the predictions are obtained with desirable deviations. The examination of the outcomes from the first stage reveals that the machining time has a significant effect on the three parameters. The regression models are found to be satisfactory in predicting each technological parameter. In the second stage, the results show a strong correlation between tool wear and cutting vibration, confirmed by the high Pearson and Spearman coefficients. The correlations between surface roughness and tool wear or the cutting vibration are strong only when the flank wear Vb is inferior 0.3 mm (which is required by the ISO standard). The regression models are developed with a desirable coefficient of regression (R2). The novelty of this work lies in the fact that we consider the cutting vibration as a response generated the during cutting process and not as a variable affecting the other technological parameters. This was rarely studied in previous researches.

18

A tool wear condition monitoring approach for end milling based on numerical simulation

Zhu Qinsong, Sun Weifang, Zhou Yuqing, Gao Chen

Eksploatacja i Niezawodność

|

2021

|

Vol. 23, no. 2

371--380

EN

As an important research area of modern manufacturing, tool condition monitoring (TCM) has attracted much attention, especially artificial intelligence (AI)- based TCM method. However, the training samples obtained in practical experiments have the problem of sample missing and sample insufficiency. A numerical simulation- based TCM method is proposed to solve the above problem. First, a numerical model based on Johnson-Cook model is established, and the model parameters are optimized through orthogonal experiment technology, in which the KL divergence and cosine similarity are used as the evaluation indexes. Second, samples under various tool wear categories are obtained by the optimized numerical model above to provide missing samples not present in the practical experiments and expand sample size. The effectiveness of the proposed method is verified by its application in end milling TCM experiments. The results indicate the classification accuracies of four classifiers (SVM, RF, DT, and GRNN) can be improved significantly by the proposed TCM method.

19

Multiobjective Performance Investigation of CNT Coated HSS Tool Under the Response Surface Methodology Platform

Chandru Manivannan, Selladurai Velappan, Venkatesh Chenrayan

Archives of Metallurgy and Materials

|

2021

|

Vol. 66, iss. 2

627--635

EN

The present research employs the statistical tool of response surface methodology (RSM) to evaluate the machining characteristics of carbon nanotubes (CNTs) coated high-speed steel (HSS) tools. The methodology used for depositing carbon nanotubes was Plasma-Enhanced Chemical Vapor Deposition (PECVD). Cutting speed, thickness of cut, and feed rate were chosen as machining factors, and cutting forces, cutting tooltip temperature, tool wear, and surface roughness were included as machining responses. Three-level of cutting conditions were followed. The face-centered, Central Composite Design (CCD) was followed to conduct twenty number of experiments. The speed of cutting and rate of feed have been identified as the most influential variables over the responses considered, followed by the thickness of cut. The model reveals the optimized level of cutting parameters to achieve the required objectives. The confirmation experiments were also carried out to validate the acceptable degree of variations between the experimental results and the predicted one.

20

Comprehensive analysis of tribological factor influence on stress-strain and thermal state of workpiece during titanium alloys machining

Stupnytskyy Vadym, She Xianning

Archive of Mechanical Engineering

|

2021

|

LXVIII, nr 2

227--248

EN

The article describes how different friction coefficients under certain cutting conditions and parameters affect the formation of the stress-strain and thermal states of the product when titanium alloy machining. A new research methodology is used for the study. Firstly, in the initial data for simulation, each time a different declared coefficient of friction is proposed, and every such task of the cutting process modelling is solved for various cutting parameters. The second stage analyzes how these coefficients influence the stress-strain and thermodynamic state of the workpiece and tool during cutting, as well as the tool wear dynamics. In the third stage of the study, ways for ensuring these analytically-grounded tribological cutting conditions are proposed. The analysis of different wear criteria in the simulation models of titanium alloys cutting is carried out. Experimental studies confirm simulation results.