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Publications (10 of 23) Show all publications
Eynian, M., Das, K. & Wretland, A. (2017). Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part I: Cutting Forces, BurrFormation, Surface Quality and Defects. High speed machining, 3, 1-10
Open this publication in new window or tab >>Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part I: Cutting Forces, BurrFormation, Surface Quality and Defects
2017 (English)In: High speed machining, E-ISSN 2299-3975, Vol. 3, p. 1-10Article in journal (Refereed) Published
Abstract [en]

Titanium's Ti6Al4V, alloy is an important material with a wide range of applications in the aerospace industry.Due to its high strength, machining this material for desired quality at high material removal rate is challenging and may lead to high tool wear rate. As a result,this material may be machined with worn tools and the effects of tool wear on machining quality need to be investigated.In this experimental paper, it is shown how drills of various wear levels affect the cutting forces, surface quality and burr formation. Furthermore, it is shown that high cutting forces and high plastic deformation, along with high temperatures that arise in cutting with worn tools may lead to initiation of microscopic cracks in the workpiece material in proximity of the drilling zone.

Place, publisher, year, edition, pages
Warsaw, Poland: De Gruyter Open, 2017
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-11875 (URN)10.1515/hsm-2017-0001 (DOI)
Available from: 2017-12-04 Created: 2017-12-04 Last updated: 2018-06-18Bibliographically approved
Das, K., Eynian, M. & Wretland, A. (2017). Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part II: Microstructure and Microhardness. High speed machining, 3, 11-22
Open this publication in new window or tab >>Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part II: Microstructure and Microhardness
2017 (English)In: High speed machining, E-ISSN 2299-3975, Vol. 3, p. 11-22Article in journal (Refereed) Published
Abstract [en]

Drilling of Ti6Al4V with worn tools can introduce superficial and easily measured features such as increase of cutting forces, entry and exit burrs and surface quality issues and defects. Such issues were presented in the part I of this paper. In part II, subsurface quality alterations,such as changes of the microstructure and microhardness variation is considered by preparing metallographic sections and measurement, mapping of the depth of grain deformation, and microhardness in these sections. Drastic changes in the microstructure and microhardness were found in sections drilled with drills with large wear lands,particularly in the dry cutting tests. These measurements emphasize the importance of detection of tool wear and ensuring coolant flow in drilling of holes in titanium components.

Place, publisher, year, edition, pages
Warsaw, Poland: De Gruyter Open, 2017
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-11876 (URN)10.1515/hsm-2017-0002 (DOI)
Available from: 2017-12-04 Created: 2017-12-04 Last updated: 2018-06-18Bibliographically approved
Devotta, A. M., Beno, T., Siriki, R., Löf, R. & Eynian, M. (2017). Finite Element Modeling and Validation of Chip Segmentation in Machining of AISI 1045 Steel. Paper presented at Conference of 16th CIRP Conference on Modelling of Machining Operations, CIRP CMMO 2017 ; Conference Date: 15 June 2017 Through 16 June 2017. Procedia CIRP, 58, 499-504
Open this publication in new window or tab >>Finite Element Modeling and Validation of Chip Segmentation in Machining of AISI 1045 Steel
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2017 (English)In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 58, p. 499-504Article in journal (Refereed) Published
Abstract [en]

The finite element (FE) method based modeling of chip formation in machining provides the ability to predict output parameters like cutting forces and chip geometry. One of the important characteristics of chip morphology is chip segmentation. Majority of the literature within chip segmentation show cutting speed (vc) and feed rate (f) as the most influencing input parameters. The role of tool rake angle (α) on chip segmentation is limited and hence, the present study is aimed at understanding it. In addition, stress triaxiality’s importance in damage model employed in FE method in capturing the influence of α on chip morphology transformation is also studied. Furthermore, microstructure characterization of chips was carried out using a scanning electron microscope (SEM) to understand the chip formation process for certain cutting conditions. The results show that the tool α influences chip segmentation phenomena and that the incorporation of a stress triaxiality factor in damage models is required to be able to predict the influence of the α. The variation of chip segmentation frequency with f is predicted qualitatively but the accuracy of prediction needs improvement. © 2017 The Authors.

Place, publisher, year, edition, pages
Elsevier B.V., 2017
Keywords
Cutting; Forecasting; Machining centers; Scanning electron microscopy; Shear stress, Chip morphologies; Chip segmentation; Cutting conditions; Damage model; Microstructure characterization; Output parameters; Stress triaxiality; Stress triaxiality factor, Finite element method
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-11909 (URN)10.1016/j.procir.2017.03.259 (DOI)2-s2.0-85029738278 (Scopus ID)
Conference
Conference of 16th CIRP Conference on Modelling of Machining Operations, CIRP CMMO 2017 ; Conference Date: 15 June 2017 Through 16 June 2017
Available from: 2017-12-13 Created: 2017-12-13 Last updated: 2017-12-22Bibliographically approved
Agic, A., Eynian, M., Hägglund, S., Ståhl, J.-E. & Beno, T. (2017). Influence of radial depth of cut on entry conditions and dynamics in face milling application. Journal of Superhard Materials, 39(4), 259-270
Open this publication in new window or tab >>Influence of radial depth of cut on entry conditions and dynamics in face milling application
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2017 (English)In: Journal of Superhard Materials, ISSN 1063-4576, Vol. 39, no 4, p. 259-270Article in journal (Refereed) Published
Abstract [en]

The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining results. Unfavorable selection of cutting conditions might give rise to high load impacts that cause severe cutting edge damage. Under some circumstances the radial depth of cut in combination with milling cutter geometry might give unfavorable entry conditions in terms of cutting forces and vibration amplitudes. This phenomenon is originated from the geometrical features that affect the rise time of the cutting edge engagement into workpiece at different radial depths of cut. As the radial depth of cut is often an important parameter, particularly when machining difficult-to-cut materials, it is important to explore the driving mechanism behind vibrations generation. In this study, acceleration of the workpiece is measured for different radial depths of cut and cutting edge geometries. The influence of the radial depth of cut on the dynamical behavior is evaluated in time and frequency domains. The results for different radial depths of cut and cutting geometries are quantified using the root mean square value of acceleration. The outcome of this research study can be used both for the better cutting data recommendations and improved tool design.

Place, publisher, year, edition, pages
New York: Allerton Press, 2017
Keywords
milling entry, radial depth, cutting edge, cutting force, vibration
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-11769 (URN)10.3103/S1063457617040062 (DOI)000409936100006 ()2-s2.0-85029210912 (Scopus ID)
Available from: 2017-10-20 Created: 2017-10-20 Last updated: 2018-08-09Bibliographically approved
Parsian, A., Magnevall, M., Beno, T. & Eynian, M. (2017). Sound Analysis in Drilling, Frequency and Time Domains. Paper presented at 16th CIRP Conference on Modelling of Machining Operations, CIRP CMMO 2017; Cluny; France; 15 June 2017 through 16 June 2017. Procedia CIRP, 58, 411-415
Open this publication in new window or tab >>Sound Analysis in Drilling, Frequency and Time Domains
2017 (English)In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 58, p. 411-415Article in journal (Refereed) Published
Abstract [en]

This paper proposes a guideline for interpreting frequency content and time history of sound measurements in metal drilling processes. Different dynamic phenomena are reflected in generated sound in cutting processes. The footprint of such phenomena including torsional, lateral regenerative chatter and whirling in sound measurement results are discussed. Different indexable insert drills, at several cutting conditions, are covered. The proposed analysis could be used for studying, online monitoring and controlling of drilling processes. © 2017 The Authors.

Place, publisher, year, edition, pages
Elsevier B.V., 2017
Keywords
Acoustic variables measurement; Architectural acoustics; Drilling; Machining centers; Vibration analysis, Chatter; Cutting conditions; Frequency and time domains; Frequency contents; Indexable inserts; Regenerative chatters; Sound analysis; Vibrations, Time domain analysis
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-11907 (URN)10.1016/j.procir.2017.03.242 (DOI)2-s2.0-85029768891 (Scopus ID)
Conference
16th CIRP Conference on Modelling of Machining Operations, CIRP CMMO 2017; Cluny; France; 15 June 2017 through 16 June 2017
Note

Available online 31 May 2017

Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2018-06-18Bibliographically approved
Parsian, A., Magnevall, M., Beno, T. & Eynian, M. (2017). Time Domain Simulation of Chatter Vibrations in Indexable Drills. The International Journal of Advanced Manufacturing Technology, 89(1-4), 1209-1221
Open this publication in new window or tab >>Time Domain Simulation of Chatter Vibrations in Indexable Drills
2017 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 89, no 1-4, p. 1209-1221Article in journal (Refereed) Published
Abstract [en]

Regenerative chatter vibrations are common in drilling processes. These unwanted vibrations lead to considerable noise levels, damage the quality of the workpiece, and reduce tool life. The aim of this study is to simulate torsional and axial chatter vibrations as they play important roles in dynamic behavior of indexable insert drills with helical chip flutes. While asymmetric indexable drills are not the focal points in most of previous researches, this paper proposes a simulation routine which is adapted for indexable drills. Based on the theory of regenerative chatter vibration, a model is developed to include the asymmetric geometries and loadings that are inherent in the design of many indexable insert drills. Most indexable insert drills have two inserts located at different radial distances, namely central and peripheral inserts. Since the positions of the central and peripheral inserts are different, the displacement and thereby the change in chip thickness differs between the inserts. Additionally, the inserts have different geometries and cutting conditions, e.g., rake angle, coating, and cutting speed, which result in different cutting forces. This paper presents a time-domain simulation of torsional and axial vibrations by considering the differences in dynamics, cutting conditions, and cutting resistance for the central and peripheral inserts on the drill. The time-domain approach is chosen to be able to include nonlinearities in the model arising from the inserts jumping out of cut, multiple delays, backward motions of edges, and variable time delays in the system. The model is used to simulate cutting forces produced by each insert and responses of the system, in the form of displacements, to these forces. It is shown that displacements induced by dynamic torques are larger than those induced by dynamic axial forces. Finally, the vibration of a measurement point is simulated which is favorably comparable to the measurement results.

Place, publisher, year, edition, pages
London: Springer London, 2017
Keywords
Chatter, Indexable insert drill, Time-domain
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology; ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-8734 (URN)10.1007/s00170-016-9137-8 (DOI)000394500300097 ()2-s2.0-84979508770 (Scopus ID)
Note

Ingår i avhandling från 2015

Available from: 2015-12-01 Created: 2015-12-01 Last updated: 2017-12-18Bibliographically approved
Agic, A., Gutnichenko, O., Eynian, M. & Ståhl, J.-E. (2016). Influence of cutting edge geometry on force build-up process in intermittent turning. Paper presented at 7th HPC 2016 – CIRP Conference on High Performance Cutting, Chemnitz, Germany, May 31-June 2, 2016. Procedia CIRP, 46, 364-367
Open this publication in new window or tab >>Influence of cutting edge geometry on force build-up process in intermittent turning
2016 (English)In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 46, p. 364-367Article in journal (Refereed) Published
Abstract [en]

In the intermittent turning and milling processes, during the entry phase the cutting edges are subjected to high impact loads that can give rise to dynamical and strength issues which in general cause tool life reduction. In this study the effect of geometrical features of the cutting tool on the force generation during the entry phase is investigated. Cutting forces are measured by a stiff dynamometer at a high sampling frequency. In addition, the chip load area is analyzed and related to the measured cutting force. The results show that micro-geometrical features, in particular the protection chamfer, significantly affect the force generation during the entry phase.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Cutting, force, edge, chip, turning, dynamic
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-9324 (URN)10.1016/j.procir.2016.04.013 (DOI)2-s2.0-84978786104 (Scopus ID)
Conference
7th HPC 2016 – CIRP Conference on High Performance Cutting, Chemnitz, Germany, May 31-June 2, 2016
Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2018-04-16Bibliographically approved
Agic, A., Eynian, M., Hägglund, S., Ståhl, J.-E. & Beno, T. (2016). Influence of radial depth of cut on dynamics of face milling application. In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016. Paper presented at 7th Swedish Production Symposium, SPS, Lund, October 25-27, 2016 (pp. 1-9). Lund: Swedish Production Academy
Open this publication in new window or tab >>Influence of radial depth of cut on dynamics of face milling application
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2016 (English)In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016, Lund: Swedish Production Academy , 2016, p. 1-9Conference paper, Oral presentation only (Refereed)
Abstract [en]

The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining results. Unfavourable selection of cutting conditions might give rise to high load impacts that cause severe cutting edge damage. The radial depth of cut in combination with milling cutter geometry might under some circumstances give unfavourable entry conditions in terms of cutting forces and vibration amplitudes. This phenomenon originates from the geometrical features that affect the rise time of the cutting edge engagement into work piece at different radial depths of cut. As the radial depth of cut is often an important parameter, particularly when machining difficult to cut materials, it is important to explore the driving mechanism behind vibrations generation. In this study, acceleration of the work piece is measured for different radial depths of cut and cutting edge geometries. The influence of the radial depth of cut on the dynamical behaviour is evaluated in time and frequency domains. The results for different radial depths of cut and cutting geometries are quantified using root mean square value of acceleration. The outcome of this research study can be used both for the better cutting data recommendations and improved tool design.

Place, publisher, year, edition, pages
Lund: Swedish Production Academy, 2016
Keywords
Milling, entry, vibration
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-10141 (URN)
Conference
7th Swedish Production Symposium, SPS, Lund, October 25-27, 2016
Available from: 2016-12-07 Created: 2016-11-16 Last updated: 2018-08-12Bibliographically approved
Eynian, M. (2016). Selection of chatter-free milling conditions using vibration frequency measurements. In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016. Paper presented at 7th International Swedish Production Symposium, SPS16, Lund, Sweden, October 25–27, 2016 (pp. 1-6). Lund: Swedish Production Academy
Open this publication in new window or tab >>Selection of chatter-free milling conditions using vibration frequency measurements
2016 (English)In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016, Lund: Swedish Production Academy , 2016, p. 1-6Conference paper, Published paper (Refereed)
Abstract [en]

Unwanted vibration of the tool with respect to the workpiece, known as chatter, can damage machine tool, cutting tool, and the surface finish of the workpiece in a machining operation such a milling. These vibrations could be avoided by reducing the depth of cut, but this approach hurts the productivity and reduces material removal rate. Previous studies have established methods, known as stability prediction methods that provide that enable using large depth of cuts while avoiding chatter. The calculation of stability lobes commonly starts by measurement of dynamic properties of the machining structure. This paper investigates an alternative approach, in which vibration frequencies gathered during test cuts with the target machining system are used to identifying the modal parameters of the machining system in its operational condition. An earlier method that was based on a one dimensional dynamics model is modified to use relationships developed for a two dimensional model that describes the dynamics of spindles and tools with axisymmetric dynamics. This approach improves the stability lobe prediction considerably as shown in results.

Place, publisher, year, edition, pages
Lund: Swedish Production Academy, 2016
Keywords
Machining dynamics, chatter, milling, stability lobe diagrams, identification
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-10240 (URN)
Conference
7th International Swedish Production Symposium, SPS16, Lund, Sweden, October 25–27, 2016
Available from: 2016-12-07 Created: 2016-12-07 Last updated: 2018-08-12Bibliographically approved
Eynian, M. & Wretland, A. (2016). Sensitivity of Axis Tracking Errors of Machine Tools to Tool Wear in Drilling. In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016. Paper presented at 7th International Swedish Production Symposium, SPS16, Lund, Sweden, October 25–27, 2016 (pp. 1-7). Lund: Swedish Production Academy
Open this publication in new window or tab >>Sensitivity of Axis Tracking Errors of Machine Tools to Tool Wear in Drilling
2016 (English)In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016, Lund: Swedish Production Academy , 2016, p. 1-7Conference paper, Published paper (Refereed)
Abstract [en]

Axis Tracking Errors (ATEs) of the active and inactive axis of numerically controlled machine tools are presented as new means of detection of tool wear that forgo expensive sensors or modifications of the machining structure, however, very little has been published about their capabilities or limitations as signal source for monitoring. In this paper the ATEs and cutting forces in drilling tests in two different machine tools, with drills of varying wear levels are measured. The sensitivity to wear is compared by introducing Percent Deviation from New Tool (PDFNT) factor, which is applied to the peak-to-peak values of the signals. While the ATEs are very small in magnitude, they are highly sensitive to wear levels, with PDFNTs reaching to 1000% for some axis. In addition, the standard deviation of PDFNTs calculated in drilling of seven holes with the same tool represents the repeatability of ATEs. The PDFNTs for ATEs are rather repeatable, but less repeatable than the PDFNTs of the axial drilling force. Furthermore it is shown that ATEs of different machine tools have different levels of sensitivity to wear levels which necessitates calibrating of monitoring systems using ATEs for each machine tool separately.

Place, publisher, year, edition, pages
Lund: Swedish Production Academy, 2016
Keywords
Tool wear, monitoring, axis tracking errors, sensitivity, repeatability, drilling
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-10246 (URN)
Conference
7th International Swedish Production Symposium, SPS16, Lund, Sweden, October 25–27, 2016
Available from: 2016-12-08 Created: 2016-12-08 Last updated: 2018-08-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9331-7354

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