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1
Content available Influence of grinding conditions on the topographic characteristic of machined surfaces
100%
Żak K.
Journal of Machine Engineering
|
2014
|
tom Vol. 14, No. 2
47--56
EN
This paper compares the ability of grinding processes to enhance functional properties of the surface textures produced. The main objective of such a comparison is to facilitate the decision about precision grinding operations. The experimental study performed includes two grinding operations using electro-corundum Al2O3 and CBN wheels. For this purpose, the topographic features of ground surfaces with the Sa roughness parameter of about 0.2?m were compared. Apart from the set of 3D roughness parameters, the frequency, fractal, wavelet and motif characteristics were analyzed.
2
Content available Energy-based characterization of precision hard machining using partially worn CBN cutting tools
100%
Grzesik W. , Denkena B. , Zak K.
Journal of Machine Engineering
|
2019
|
tom Vol. 19, No. 2
54--62
EN
This paper highlights the performance of precision hard turning with CBN cutting tools from energy point-of-view with additional tool wear effect. For this purpose several wear tests were performed during which the tool nose wear VBC and the corresponding changes of component forces Fc, Ff and Fp were continuously measured. Based on the measured forces and geometrical characteristic of the uncut layer, specific cutting and ploughing energy were determined for several combinations of cutting parameters. Consequently, changes of energy consumption resulting from tool wear evolution for variable feed rate, depth of cut and tool nose radius were presented.
3
Obróbka na twardo a szlifowanie
100%
Siwiec J.
Świat Obrabiarek
|
2010
|
tom R. 5, nr 1-2
20-21
PL
W czasach rosnącej globalizacji gospodarki na świecie, przyglądamy się zmaganiom konwencjonalnych i nowych technologii produkcji. Te ostatnie mają między innymi poprawić produktywność, jakość wyrobów, elastyczność i ekologiczność procesów obróbki. Za przykład nowych technologii można podać wciąż rozwijającą się obróbkę z dużymi prędkościami skrawania HSC (High Speed Cutting), obróbkę wysokowydajną HPC (High Performance Cutting), oraz obróbkę na twardo HM (Hard Machining).
4
Content available Influence of the path type on selected technological effects in the trochoidal milling
100%
Waszczuk K. , Karolczak P. , Wiśniewska M. , Kowalski M.
|
2017
|
tom Vol. 11, no 1
147--153
EN
The article presents basic information about machining materials in hardened state – it particularly describes a method of the so called hard milling. The paper discusses strategies and methods in hard milling, presents trochoidal milling, its advantages and disadvantages. It also presents research methodology and effects which concerned determination of a tool path impact on selected technological effects after trochoidal milling of the groove.
5
Content available Areal field and fractal based characterization of hard surfaces produced by different machining operations
88%
Zak K.
Journal of Machine Engineering
|
2016
|
tom Vol. 16, No. 1
24--32
EN
This literature survey highlights the possible influences of surface roughness parameters on functional properties of surfaces produced by different finishing operations. The prediction of such functional properties as fatigue, sealing capacity, adhesion, friction, wear and corrosion resistance based on five groups of spatial (S) roughness parameters is overviewed. In contrast, traditional approach based on 2D roughness parameters is provided. Some real 3D surface topographies produced with desired functional properties by finishing cutting and abrasive operations are characterized. This survey confirms the vital role of machined surfaces in the functionality of machine components.
6
Content available remote Correlation analysis between tool wear, roughness and cutting vibration in turning of hardened steel
88%
Abidi Y. , Boulanouar L.
Engineering Transactions
|
2021
|
tom 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.
7
Content available remote Effect of cutting parameters on chip formation in orthogonal cutting
88%
Ben Salem S. , Bayraktar E. , Boujelbene M. , Katundi D.
Journal of Achievements in Materials and Manufacturing Engineering
|
2012
|
tom Vol. 50, nr 1
7--17
EN
Purpose: of this paper is to study the chip formation to obtain the optimal cutting conditions and to observe the different chip formation mechanisms. Analysis of machining of a hardened alloy, X160CrMoV12-1 (cold work steel: AISI D2 with a ferritic and cementite matrix and coarse primary carbides), showed that there are relationships between the chip geometry, cutting conditions and the different micrographs under different metallurgical states. Design/methodology/approach: Machining of hardened alloys has some metallurgical and mechanical difficulties even if many successful processes have been increasingly developed. A lot of study has been carried out on this subject, however only with modest progress showing specific results concerning the real efficiency of chip formation. Hence, some crucial questions remain unanswered: the evolution of white layers produced during progressive tool flank wear in dry hard turning and to correlate this with the surface integrity of the machined surface. For the experimental study here, various cutting speeds and feed rates have been applied on the work material. Findings: The “saw-tooth type chips” geometry has been examined and a specific attention was given to the chip samples that were metallographically processed and observed under scanning electronic microscope (SEM) to determine if white layers are present. Research limitations/implications: This research will be followed by a detail modelling and need more experimental results for a given a good prediction of the results occurred on the damage related to the microstructure by using the cutting parameters. Practical implications: A special detail was given to the mechanism of chip formation resulting from hard machining process and behaviour of steel at different metallurgical states on the material during the case of annealing and or the case of quench operations. Originality/value: For the sake of simplicity, ANOVA (Analysis of Variance) was used to determine the influence of cutting parameters. It gives a practical and useful tool for the machining in the industrial operations.
8
Struktura geometryczna powierzchni w skrawaniu materiałów utwardzonych
75%
Bogdan M.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
|
2013
|
tom z. 102
17-18
EN
This paper demonstrates characteristics of hard machining processing. Surface roughness and tool wear in hard turning using cubic boron nitride tools is presented. Additionally, this article shows potential advantages of hard turning process.
9
Content available Influence of the Trochoidal Tool Path on Quality Surface of Groove Walls
63%
Waszczuk K. , Skowronek H. , Karolczak P. , Kowalski M. , Kołodziej M.
Advances in Science and Technology. Research Journal
|
2019
|
tom Vol. 13, no 3
38--42
EN
The article presents the results of machining materials in hardened state. In the paper, different trochoidal tool paths are compared with each other and with the conventional milling. The results of measurements show the relationship between tool path, roughness and waviness of grooves wall. The paper also presents pictures of grooves which were made. These results provide comparative material useful in the choice of the best milling strategy to the cutting process.
10
Content available Influence of the Trochoidal Tool Path Generation Method on the Milling Process Efficiency
63%
Waszczuk K.
Advances in Science and Technology. Research Journal
|
2020
|
tom Vol. 14, no 3
199--203
EN
The article presents a comparison of three trochoidal paths: written by G-Code, generated using the overlays from the machine level, and generated using the CAD/CAM environment. The parameters determining the effectiveness of the process were: maximum achievable feed speed, surface roughness and waviness, cutting forces and cutting temperature when milling NC6 steel (50HRC) using a 10 mm cutter dimeter. The main measurement results include: an increase in the maximum feed speed value by almost 35% when using the A and C paths compared to the type B path and nearly a double increase in surface roughness when using the path generated using the CAD/CAM environment compared to the B path. The most important conclusions was that it is not always possible to machine with the recommended parameters by the tool manufacturer, especially when machining narrow grooves. It was proven that that the use of paths with the displacement described by arcs and straight lines as a trochoidal step over reduces the possibility of milling at high feed rate.
11
Content available remote Obróbka materiałów w stanie utwardzonym
63%
Siwiec J.
Czasopismo Techniczne. Mechanika
|
2011
|
tom R. 108, z. 5-M
93-100
PL
W czasach rosnącej globalizacji gospodarki na świecie przyglądamy się zmaganiom konwencjonalnych i nowych technologii produkcji. Te ostatnie mają poprawić m.in. produktywność, jakość wyrobów, elastyczność i ekologiczność procesów obróbki. Dzięki rozwojowi technologii obróbki, a przede wszystkim nowym materiałom konstrukcyjnym narzędzi skrawających jak polikrystaliczny regularny azotek boru, oraz rozwojowi konstrukcji obrabiarek udaje się obniżyć koszty produkcji nawet o 80%. W artykule przedstawiono charakterystykę obróbki w stanie utwardzonym oraz tendencje rozwoju, koncentrując się głównie na tzw. toczeniu na twardo. Zaprezentowano także konfrontację technologii szlifowania i alternatywnej dla niej obróbki w stanie utwardzonym.
EN
In an era of increasing globalization of the economy in the world, we are witnessing the struggle of conventional and new production technologies. The latter are designed to improve productivity, product quality, flexibility and environmental performance of production processes. Both the development of processing technologies, and above all, the new cutting tools construction materials such as regular polycrystalline cubic boron nitride (PCBN) and the development of the construction machine tools enable to reduce production costs by up to 80%. This paper presents the characteristics of hard machining processing and development trends, focusing mainly on the so-called hard part turning technology. It shows the confrontation between grinding and alternative technologies for its hard part turning.
12
Content available remote Efekty technologiczne obróbki na twardo materiałów metalowych.
63%
Kawalec M.
Mechanik
|
2006
|
tom R. 79, nr 1
20-26
PL
Przeznaczenia, charakterystyka i zalety obróbki na twardo. Przykłady wyrobów ksztaltowanych obróbką na twardo. Chropowatość powierzchni obrobionej i stabilność krawędzi skrawającej. Dokladność obróbki. Cechy fizyczne warstwy wierzchniej po obróbce. Nowe trendy w obróbce na twardo.
EN
Application, specific features and advantages of the hard machining process. Roughness of the machine surface against stability of cutting edge. Machining precision. Physical features of the top surface after hard machining operation. New tendencies in hard machining process methods.
13
Content available remote Wpływ geometrii przekroju poprzecznego warstwy skrawanej w strefie przy osi wiertła na jego obciążenie
63%
Nowakowski Z.
Archiwum Technologii Maszyn i Automatyzacji
|
2004
|
tom Vol. 24, nr 2
69-76
PL
W artykule przedstawiono wyniki pomiarów sił dla różnych konstrukcji wierteł z płytkami wymiennymi. Pomiary wykonano podczas obróbki stali WCL w stanie miękkim (295 HV02) i zahartowanym (58 HRC). Przeanalizowano wpływ przekroju poprzecznego warstwy skrawanej w strefie przy osi wiertła na wartość siły promieniowej F,7, oraz wypadkowej siły odporowej Fp. Oceniono zmiany stosunku obciążenia ostrza wewnętrznego do zewnętrznego dla wiertła z płytkami wymiennymi w zależności od stanu materiału obrabianego (miękki, zahartowany).
EN
In the article results of forces measurements for various constructions of indexable insert drills have been shown. Measurements have been carried out during machining of the WCL steel in soft (295 HVo,2) and hardened (58 HRC) state. Influence of cut form in zone near axis of the drills on value of radial force F,.p and resultant thrust force F,, has been analyzed. Comparison of changes of load on internal wedge to load on external wedge ratio for given construction of indexable insert drill depending on state of work material (soft, hardened) has been done as well.
14
Content available Analysis of the compromise between cutting tool life, productivity and roughness during turning of C45 hardened steel
63%
Abidi Y.
Production Engineering Archives
|
2021
|
tom 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.
15
Content available Relationship between surface roughness and chip morphology when turning hardened steel
63%
Abidi Y.
Production Engineering Archives
|
2020
|
tom Vol. 26, Iss. 3
92--98
EN
Hard machining is a process which has become highly recommended in manufacturing industry to replace grinding and perform production. The important technological parameters that determine this process are tool wear, machined surface roughness, cutting force and morphology of the removed chip. In this work, an attempt has been made to analyse the morphology and form of chip removed during turning of hardened steel AISI 1045 (40HRC) with mixed ceramic tool type CC650. Using a Taguchi plan L9, whose factors are cutting speed and feed rate with three levels for each. Macroscopic and microscopic results of chip morphology were correlated with these two cutting parameters additional to surface roughness. Sufficient experimental results were obtained using the mixed ceramic tool when turning of hardened steel AISI 1045 (40HRC) at high cutting speeds. Roughness of machined surface confirmed that it is influenced by feed rate. Chips show a sawtooth shape for all combinations of the experimental plan used. The chip form changed with cutting parameters variation and given an important indicator of suraface quality for industriel. Having the indicators on the surface quality from simple control of chip without stopping machining give an important advantage in order to maximize production and reduce costs.
16
Content available remote Wear of ceramic tools in hard machining
63%
Grzesik W.
Journal of Achievements in Materials and Manufacturing Engineering
|
2008
|
tom Vol. 26, nr 2
127-130
EN
Purpose: The principle purpose of this investigation is to recognize the wear phenomenon of the mixed ceramic tips against 60 HRC alloy steel specimens in dry and hard turning operations. This knowledge allows optimal machining chains to be planned by the manufacturing engineers. Design/methodology/approach: Light optical microscopy (LOM), scanning electron microscopy (SEM), BSE technique and X-ray diffraction analysis (XRM) were applied for observations of worn tool surfaces, wear products and the distinction of wear mechanisms occurring. Findings: It was found that wear mechanisms observed in the machining tests involve abrasion, fracture, plastic flow, material transfer and tribochemical effects which appear depending on the mechanical and thermal conditions generated on the wear zones. Research limitations/implications: Investigations were performed under varying feed rate, constant cutting speed of 100 m/min and small depth of cut of 0.2 mm to perform finishing cuts. Practical implications: In this study both microscopic and microstructural aspects of ceramic tool wear were taken into consideration. Moreover, the development of the crater and flank wear and the associated wear mechanisms were identified. Originality/value: In particular, two types of transfer layer formation with different morphologies occurring at the rake-chip interface are distinguished.
17
Obróbka materiałów w stanie utwardzonym
63%
Siwiec J.
Świat Obrabiarek
|
2010
|
tom R. 5, nr 7-9
23-26
PL
W czasach rosnącej globalizacji gospodarki na świecie przyglądamy się zmaganiom konwencjonalnych i nowych technologii produkcji. Te ostatnie mają poprawić m.in. produktywność, jakość wyrobów, elastyczność i ekologiczność procesów obróbki. Dzięki rozwojowi technologii obróbki, a przede wszystkim nowym materiałom konstrukcyjnym narzędzi skrawających jak polikrystaliczny regularny azotek boru (ang. polycrystalline cubic boron nitride, w skrócie PCBN) oraz rozwojowi konstrukcji obrabiarek udaje się znacząco obniżyć koszty produkcji. Artykuł przedstawia charakterystykę obróbki w stanie utwardzonym oraz tendencje rozwoju, koncentrując się głównie na tzw. toczeniu oraz frezowaniu na twardo. Ukazuje także konfrontację technologii szlifowania i alternatywnej dla niej obróbki w stanie utwardzonym.
EN
Observing the increasing globalization of the economy, we are witnessing the struggle of conventional and new production technologies. The latter are designed to improve productivity, product quality, flexibility and environmental performance of production processes. Both the development of processing technologies, and above all, the new cutting tools construction materials such as regular polycrystalline boron nitride (PCBN) and the development of the construction machine tools enable to reduce significantly production costs. The article presents the characteristics of hard machining processing and development trends, focusing mainly on the so-called hard part turning and hard part milling technology. It shows the confrontation between grinding and alternative technologies for its hard part turning.
18
Content available remote Application of continuous wavelet transform for assessment for surface roughness profile after machining of hardened AlSI 52100 steel
63%
Brol S. , Grzesik W.
Archive of Mechanical Engineering
|
2007
|
tom Vol. LIV, nr 2
147-154
EN
In this paper, the authors present surface roughness profile assessment using continuous wavelet transform (CWT). Roughness profiles after turning and rough and finish belt grinding of hardened (62HRC) AISI 52100 steel are analyzed. Both Morlet and “Mexican hat” analyzing wavelets are used for the assessment of extrema and frequency distribution. The results of the CWT as a function of profile and momentary wavelet length are presented. It is concluded that CWT can be useful for the analysis of the roughness profiles generated by cutting and abrasive machining processes.
PL
W artykule autorzy przedstawili sposób oceny profili chropowatości powierzchni z wykorzystaniem ciągłego przekształcenia falkowego (CPF). Przedmiotem analizy falkowej były profile po toczeniu na twardo oraz wstępnym i wykańczającym szlifowaniu taśmowym stali AISI 52100 w stanie utwardzonym. Wykorzystano dwie falki analizujące: „Meksykański kapelusz” i falkę Mor- leta do oceny odpowiednio: rozkładu ekstremów oraz częstotliwości i amplitudy falek składowych. Wyniki przekształcenia falkowego przedstawiono w funkcji długości profilu i chwilowej długości falki analizującej. Stwierdzono, że CPF może być wykorzystywane do analizy profili chropowatości powierzchni zarówno po obróbce ostrzem o określonej geometrii, jak i po obróbce ściernej.
19
Content available remote An investigation of 2D and 3D-surface microtopography produced by hard part machining.
51%
Grzesik W. , Wanat T.
Advances in Manufacturing Science and Technology
|
2004
|
tom Vol. 28, nr 4
5-16
EN
The main aim of the study is assessment and comparison of the measured surface profiles (2D-arragement) and surface microstereometries (3D-arrangement) produced during hard part turning operations keeping different machining conditions. As a result the paper provides a special contribution to surface roughness generation when turning a 40H low chromium alloy steel (equivalent To AlSl 5140 or DIN 41Cr4) heat treated to the hardness of about 60 HRC, with mixed ceramic cutting tools. Comparable surface roughness values were produced in finish turning with Ra values of about 0,25 micrometer. Some results obtained are compared with those related to finish grinding available in literature.
PL
Głównym zadaniem przedstawionych badań jest ocena i porównanie mierzonych profili powierzchni (odwzorowanie 2D) i mikrostereometrii powierzchni (odwzorowanie 3D) wytworzonej podczas operacji toczenia na twardo w różnych warunkach obróbki. Wyniki stanowią specjalny wkład do generowania chropowatości powierzchni w toczeniu narzędziami z ceramiki mieszanej niskostopowej stali 40H (równoważnej gatunkom AlSI 5140 i DIN 41Cr4) obrobionej cieplnie do twardości około 60 HRC. W operacjach wykańczających wytwarzano porównywalne wartości i chropowatości powierzchni o Ra około 0,25 mikrometra. Niektóre uzyskane wyniki porównano do odpowiednich rezultatów szlifowania wykańczającego dostępnych w literaturze.
20
Content available remote Innowacyjne technologie: obróbka materiałów w stanie utwardzonym
51%
Siwiec J.
Obróbka Metalu
|
2011
|
tom nr 4
37-39
PL
Zmagania konwencjonalnych i nowych technologii produkcji trwają już od wielu lat. Specjaliści z całego świata głowią się nad problemem poprawy produktywności, jakości wyrobów, elastyczności i ekologiczności procesów produkcyjnych. Wszystko po to, aby spełnić coraz to nowsze normy i wymagania swoich klientów. To, co kiedyś wykraczało poza oczekiwania klientów, dziś stało się normą. Jak zatem zaspokoić wciąż rosnące oczekiwania? Z pomocą mogą przyjść nam innowacyjne technologie produkcji. Jedną z takich technologii jest obróbka materiałów w stanie utwardzonym, a w szczególności upowszechniające się tzw. toczenie na twardo. Publikacja przedstawia charakterystykę obróbki materiałów w stanie utwardzonym, konfrontację z technologią szlifowania oraz kierunki rozwoju.
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