Wyniki wyszukiwania - Biblioteka Nauki

1

Cutting Force Reduction in The Milling of Aluminum Alloys with Serrated Cutting Tool Edges

100%

Rekers S. , Auerbach T. , Veselovac D. , Klocke F.

Journal of Machine Engineering

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2015

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tom Vol. 15, No. 4

27--36

EN

Structural components for aerospace industry are in most cases milled from solid. Usually more than 80 % of the bulk material is removed by milling processes in order to obtain the parts final shape. Due to economic aspects, high material removal rates are desired to reduce cost intensive machine cycle times. In order to meet high process design demands, optimized cutting forces at maximized material removal rates are of crucial interest. These are especially depending on the work piece material to be machined, the cutter work piece engagement conditions as well as the milling cutters geometry. The usage of milling tools with serrated cutting edge geometries enables a significant reduction of cutting forces. In this article, cutting forces during milling aluminum alloys using different serration geometries and engagement conditions are investigated. At first, a generic cutting force model is introduced. The required model parameters are approximated for the machined material by subsequent milling tests employing non-serrated cutters. In a second step, a model is presented allowing a time-domain simulation to obtain cutting force variations for cutters with serrated cutting edges. Finally, experimental data for different serrated cutters are compared with the simulated predictions.

2

Modeling of Vibration Behaviors of Turning Machining with the Constant Surface Speed Effect

100%

Royandi M. A. , Effendi I. A. , Ibrahim B. , Hung J. P.

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tom Vol. 15, no 3

134--145

EN

Turning machining is a complex process in which many variables can influence the desired results. Among those variables, cutting tool vibration and cutting force greatly affect the precision of the workpiece and the tool life. While the tool vibration and cutting force in feeding are primarily determined by cutting speed, feed rate, and depth of cut as well as the dynamic characteristics of the machining system. This paper presents an analytical modeling approach to investigate the effects of machining conditions based on the governing equation of the machining system. The machining behaviors under different conditions were simulated by Simulink block diagram. Basically, the cutting speed is considered the parameter dominating the vibration behavior and hence is served as the primary input for the simulation. The effectiveness of constant surface speed (CSS mode) or function G96 in the turning process was further examined through comparisons of the variations of vibration and cutting force generated in feeding with different conditions.

3

Cutting forces in dry and near dry cutting off machining

100%

Leppert T.

Journal of Polish CIMAC

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2013

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tom Vol. 8, no 3

37--43

EN

The article presents research results on the effect of cooling and lubrication on the cutting force in cutting off process of A11and C45 steel rods using different rake face shapes and cutting parameters. The aim of the investigation was to determine outcomes of elimination (dry cutting) or reduction (minimum quantity lubrication – MQL) of a cooling and lubricating fluid in the cutting off process. It has been concluded that the minimum quantity lubrication allowed decreasing the cutting force compared to dry cutting. The impact of eliminating or reducing the quantity of the cooling and lubricating medium on the cutting force in the cutting off process of both types of steel depend on the applied feed rate and cutting speed. Taking into account environmental reasons, the dry and MQL cutting off is advisable and highly justifiable.

4

A review on machinability in the milling processes

100%

Demirpolat H. , Kuntoğlu M. , Binali R.

Sustainable Production, Instrumentation and Engineering Sciences

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2023

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tom 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

Identification of dynamic cutting force coefficients by direct measurement of cutting forces during vibratory cutting

100%

Jemielniak K. , Nejman M. , Sniegulska-Gradzka D.

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2016

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tom Vol. 16, No. 3

47--57

EN

This paper presents the methodology of measuring the instantaneous cutting forces during vibratory cutting. It is based on elastically supported dynamometer vibrating with the tool during chatter. Acceleration of the dynamometer measured simultaneously allows for evaluation and elimination of inertia forces acting on the oscillating dynamometer. Displacements of the dynamometer and the tool in the feed direction during orthogonal cutting are measured by the contactless inductive sensor. The measurements allow for determination of averaged or instantaneous dynamic cutting force coefficients and their dependence on cutting conditions.

6

The effect of machining conditions on the forces in the process of roller brush machining

100%

Matuszak J.

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tom Vol. 11, no 4

294--300

EN

Because of its advantages, brushing processing has many uses. The main ones include the removal of corrosion products, surface cleaning, deburring and shaping the properties of the surface layer. The intensity of these processes depends on the degree of impact of brush fibres on the work surface. In the case of tools, in which the resilient fibres are the working elements, forces in the brushing process, apart from the machining parameters, depend on the characteristics and overall dimensions of individual fibres. The paper presents the results of studies of the influence of technological parameters and type of fibres on the radial force in the brushing process.

7

Impact of cutting tool geometry on the dynamic load of system in the machining process of nickel Alloy 625

100%

Hajnyš J. , Zlámal T. , Petrů J. , Pagáč M. , Rudawska A.

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tom Vol. 10, nr 32

24--31

EN

The article is focussed on comparing and determining the impact of the cutting geometry of the cutting tool due to dynamic load on system and microgeometry machined surface. For longitudinal turning nickel alloy Alloy 625 (W. Nr. 2.4856) rounded indexable cutting insert was used (RCMT 10T3M0 – F2) and its equivalent squared indexable cutting insert (SNMG 120412 – MR3) coated with fine-grained PVD (Ti, Al) N + TiN. Experimental testing of nickel Alloy 625 was under predetermined cutting conditions. In the selected depth of the removed material of 0.5 mm and 1.5 mm was measured in the course of machining the size of the individual components of cutting forces.

8

Workpiece temperature variations during flat peripheral grinding

100%

Smirnov V. A. , Repko A. V.

Management Systems in Production Engineering

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2018

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tom nr 2 (26)

93--98

EN

The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed ther-mophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.

9

Artificial neural network modelling of cutting force components during AZ91HP alloy milling

100%

Kulisz M. , Zagórski I. , Semeniuk A.

Applied Computer Science

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2016

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tom Vol. 12, no 4

49--58

EN

The paper presents simulation of the cutting force components for ma-chining of magnesium alloy AZ91HP. The simulation employs the Black Box model. The closest match to (input and output) data obtained from the machining process was determined. The simulation was performed with the use of the Statistica programme with the application of neural networks: RBF (Radial Basis Function) and MLP (Multi-Layered Perceptron).

10

Effect of silicon content on machinability of AL-SI alloys

100%

Akyüz B.

Advances in Science and Technology. Research Journal

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2016

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tom Vol. 10, nr 31

51--57

EN

In this study the effect of the change in the amount of Silicon (Si) occuring in Al-Si alloys on mechanical and machinability properties of the alloy was investigated. The change in mechanical properties and microstructure, which depends on the increase in Si percentage, and the effects of this change on Flank Build-up (FBU), wear on the cutting edge, surface roughness, and machinability were also studied. Alloys in different ratios of Si (i.e. 2 to 12 wt %), were employed in the study. The specimens for tests were obtained by casting into metal moulds. The results obtained from experimental studies indicate improved mechanical properties and machinability, depending on the rise in Si percentage in Al-Si alloys. It is also observed that the increase in Si percentage enhanced surface quality.

11

MDF - machinability during drilling

88%

Podziewski P. , Gorski J. , Czarniak P. , Wilkowski J. , Szymanowski K. , Cyrankowski M.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 87

12

Impact of the feed force on discontinuity of wood cutting with petrol chainsaw

88%

Maciak A.

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nr 66 Agric.Forest Eng.

13

Effect of thermal modification temperature of spruce wood on cutting parameters during circular saw blade cutting

88%

Hlásková L. , Kopecký Z. , Novák V.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2021

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tom No. 113

30--35

EN

Effect of thermal modification temperature of spruce wood on cutting parameters during circular saw blade cutting. The work examines the effect of temperature on energetical parameters (specific cutting resistance and cutting force) when cutting heat-treated wood of Norway spruce (Picea Abies) by a circular saw. The test samples were heat-treated at 160°C, 180°C, 200°C and 220°C. One sample was not heat treated and was used as a reference sample. In comparison with the theoretical assumptions, the influence of temperature on the cutting force and specific cutting resistance was confirmed. With increasing temperature of modification, the specific cutting resistance and cutting force decreased. The reduction of value of cutting force is related to changes in the chemical structure of the wood components, weight and density loss due to the increasing temperature of modification.

PL

Wpływ temperatury modyfikacji termicznej drewna świerkowego na parametry skrawania podczas cięcia piłą tarczową. W pracy zbadano wpływ temperatury modyfikacji na parametry skrawania (oprór skrawania i siła skrawania) przy cięciu piłą tarczową drewna świerka pospolitego (Picea Abies) poddanego obróbce termicznej. Próbki drewna do badań poddano obróbce w temperaturze 160°C, 180°C, 200°C i 220°C. Jako wariant kontrolny wykorzystano drewno naturalne (nie poddane obróbce termicznej). W ramach badan potwierdzono wpływ temperatury modyfikacji na siłę skrawania i opory skrawania drewna. Wraz ze wzrostem temperatury modyfikacji zmniejszały się wartosci oporu skrawania i siły skrawania. Zmniejszenie wartości siły skrawania związane jest ze zmianami struktury chemicznej składników drewna, ubytkiem masy i gęstości pod wpływem wzrostu temperatury modyfikacji.

14

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

88%

Zhu Q. , Sun W. , Zhou Y. , Gao C.

Eksploatacja i Niezawodność

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2021

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tom 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.

15

Analysing the impact of cutting force and vibration on surface roughness in external cylindrical grinding of SKH2 steel

88%

Hoang L. , Nguyen L. T.

Journal of Machine Engineering

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2023

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tom Vol. 23, No. 3

130--140

EN

The surface roughness of a part during external cylindrical grinding is directly impacted by cutting force and vibration, which are intermediate parameters. To improve the quality of finished parts, studying and controlling these parameters is essential. In this research, the Taguchi method combined with ANOVA analysis was utilized to analyse the effects of feed rate, cutting depth, and rotational speeds on cutting force and vibration amplitude. The test material used was SKH2 steel, which was heat-treated to a hardness of 60 HRC. The research aimed to investigate the relationship between cutting force, vibration, and surface roughness. The study concludes with an analysis of the influence of cutting force and vibration on the surface roughness of parts during external cylindrical grinding. The results show that as cutting force and vibration increase, the surface roughness of the workpiece in external grinding will also increase, and conversely when cutting force and vibration decrease, the surface roughness will decrease.

16

Path Interval and Its Relevance to Cutting Force in Ball and Filleted End Milling

88%

Sekine T.

Advances in Science and Technology. Research Journal

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2022

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tom Vol. 16, no 1

85--94

EN

Computerized milling process is widely used in product manufacturing. Although manufacturing has gradually become highly-automated, the selection of machining conditions still remains an ever-present challenge in the process. To provide some findings contributable for the process planning, this study focuses on ball and filleted end milling. After brief explanations were given to the path interval determinations in both milling processes, the experiments were conducted to verify and characterize each procedure. The results of computational procedures showed good agreement with the experimental ones. Then, material removal rate and cutting force were analytically proposed for effective selection of machining conditions. The following findings were obtained from the demonstrations with discussion. Ball end milling required relatively large cutting force in the first tool path even though the material removal rate was comparatively small. On the contrary, filleted end mill enabled us to maintain a moderate cutting force in the first tool path even if the material removal rate expanded with increasing tool radius.

17

Ispravlenie pogreshnosti raspolozhenija osi otverstija kombinirovanym osevym instrumentom

88%

Stepanov M. , Ivanova M.

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tom 17

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nr 7

18

Simulation testing of the machine tool equipped with the active feed drive

88%

Sveda J. , Valasek M. , Sika Z.

Journal of Machine Engineering

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2009

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tom Vol. 9, No. 2

81--92

EN

The vibration of a machine tool is mainly caused by the dynamic acceleration of a motion axis and by the forces that act on it. All the disturbance forces are transmitted to the machine tool frame through the drive (motor) and its regulation loop and they excite its vibrations. Thus the achievable dynamics and machining quality is negatively influenced. There are several possibilities how to suppress the excited vibrations including the recently introduced "motor on motor" technique which is based on the serial connection of two linear motors. This paper presents new simulation results performed on the simulation model of a real machine tool. The maximal achievable tuning of the regulation loop parameters of the motion axis equipped with the "motor on motor" technique was confronted with the conventional feed drive setting. The "motor on motor" feed drive properties were also tested in the virtual machining operation mode where the real measured cutting force was used. The sensitivity analysis of the reaction force and the middle mass movement of the "motor on motor" feed drive solution to the predicted cutting force introduced to the feed drive control has been investigated. The middle mass is represented by the shared part of both linear motors which absorbs the high frequency part of the reaction force by its movement.

19

Evaluation of the cutting force components and the surface roughness in the milling process of micro-and nanocrystalline titanium

88%

Habrat W. , Motyka M. , Topolski K. , Sieniawski J.

Archives of Metallurgy and Materials

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2016

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tom Vol. 61, iss. 3

1379--1384

EN

Nanocristalline pure titanium in comparison to inicrocrystalline titanium is characterized by better mechanical properties which influence its wider usability. The aim of the research was to evaluate whether the grain size of pure titanium (micro- and nanocrystalline) has influence on the cutting force components and the surface roughness in the milling process. Models of cutting force components for both materials were prepared and differences between the results were examined. The feed rate effect on selected parameters of surface roughness after milling of micro- and nanocrystalline pure titanium was determined.

20

Dobór siły skrawania na kole czerpakowym koparek na podstawie badań oporów urabiania

75%

Alenowicz J. , Onichimiuk M. , Wygoda M.

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tom R. 51, nr 5

15-19

PL

Przedstawiono dotychczasowy deterministyczny model składowej stycznej siły skrawania na kole czerpakowym koparki. Zaprezentowano nowy statyczny model składowej stycznej powyższej siły. Opisano zalety wynikające z zastosowania tego modelu w projektowaniu i eksploatacji koparek kołowych, Podano przykład praktycznego zastosowania modelu statystycznego przy doborze wartości składowej stycznej siły urabiania i wymaganej mocy napędu mechanizmu układu urabiania dla planowanej nowej koparki kołowej, przeznaczonej do urabiania odpadów paleniskowych jednej z krajowych elektrowni węglowych.

EN

Former deterministic model of cutting force tangent component on a bucket wheel has been discussed. A new static model of tangent component of above-mentioned force has been presented. Merits resulting from utilization of this model in bucket wheel excavators designing and exploitation have been described. An example of practical utilization of the static model in order to select proper value of cutting force tangent component and required power of mining system driving gear for planned construction of a new bucket wheel excavator designed for furnace wastes exploitation in one of domestic coal power plants have been presented.