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ScienceDirect ScienceDirect Procedia Engineering 00 (2017)000–000
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ScienceDirect
Procedia Engineering 00 (2017)000–000
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Procedia Engineering 206 (2017) 1044–1048
International Conference on Industrial Engineering, ICIE 2017 International Conference on Industrial Engineering, ICIE 2017
Thermomechanical Fatigue of Abrasive Grain Thermomechanical Fatigue of Abrasive Grain D.V. Ardashev* D.V. Ardashev* South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation South Ural State University, 76, Lenin Avenue, Chelyabinsk 454080, The Russian Federation
Abstract Abstract The article contains the results of the research intp microcutting processes of different materials with single abrasive grains. The research was conducted on the of face-grinding with a special device allows separate abrasive The article contains the results the researchmachine intp microcutting processes ofinstalled differentwhich materials withsetting singlethe abrasive grains. The grains microcutting. One of the factors changing thedevice research is thewhich temperature the processed sample. A researchand wasdoconducted on the face-grinding machine with during a special installed allows of setting the separate abrasive different temperature of the sample was achieved with the help of the gas burner. The results of the research made it possible to grains and do microcutting. One of the factors changing during the research is the temperature of the processed sample. A define thetemperature coefficient of ofthe thermomechanical fatigue forthe each combination of processing modeofand of the material and its different sample was achieved with help of the gas burner. The results the type research made it possible to changing to the temperature of the grinding sample. The results will help develop the methodology of the projecting define thedue coefficient of thermomechanical fatigue for each combination of to processing mode and type of materialeffective and its grinding a wide variety of grinding technological conditions, with respect to develop the working capacity of theofabrasive tool. changingoperations due to the in temperature of the sample. The results will help to the methodology projecting effective © 2017 The Authors. Published by Elsevier B.V. grinding operations in a wide variety of technological conditions, with respect to the working capacity of the abrasive tool. © 2017 The under Authors. Published by Elsevier Ltd. Peer-review responsibility of Elsevier the scientific of the International Conference on Industrial Engineering. © 2017 The Authors. Published by B.V. committee Peer-review under responsibility of the fatigue; scientific committee of the International Conference on Industrial Engineering Keywords: microcutting; thermomechanical grinding. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering. Keywords: microcutting; thermomechanical fatigue; grinding.
1. Introduction 1. Introduction Regime-tool equipment of grinding operations for short-run environment has to consider tool working capacity which will help equipment to project effective operations of machining. Today the task ishas to to develop an tool integrated generalized Regime-tool of grinding operations for short-run environment consider working capacity model will of the wear abrasive tool which considers all its mechanisms and fatigue in order which help to of project effective operations of machining. Today thesuch taskasisphysicochemical to develop an integrated generalized to predict working grinding all wheels while processing various makes of andinalloys. model of the wear ofcapacity abrasive of tooldifferent which considers its mechanisms such as physicochemical andsteel fatigue order Physicochemical interaction processing material studied earlier. a result of to predict working capacity ofofabrasive differentand grinding wheels whilewas processing variousAs makes of the steelcoefficient and alloys. chemical affinity interaction for the range grinding and alloys was got. is an aggregate intensity of reactive Physicochemical of of abrasive andsteel processing material was Itstudied earlier. Asofa the result the coefficient of diffusion affinity process for when abrasive grain steel contacts work grinding of [1,2]. There areofscientific chemical the the range of grinding and the alloys wasmaterial got. It iswhile an aggregate the intensity reactive researches that dealwhen with the strength characteristics of abrasive grain while grinding [3-11] but theyThere do notareaccount for diffusion process abrasive grain contacts the work material while grinding [1,2]. scientific researches that deal with strength characteristics of abrasive grain while grinding [3-11] but they do not account for
* Corresponding author. Tel.: +7-922-230-4807. E-mail address:author.
[email protected] * Corresponding Tel.: +7-922-230-4807.
E-mail address:
[email protected] 1877-7058 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering . 1877-7058 © 2017 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering .
1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the International Conference on Industrial Engineering. 10.1016/j.proeng.2017.10.592
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D.V. Ardashev / Procedia Engineering 206 (2017) 1044–1048 D.V. Ardashev / Procedia Engineering 00 (2017) 000–000
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different temperature in a cutting zone. The goal of this article is to research thermomechanical fatigue wear of abrasive grain by a microcutting method. Nomenclature y n kf T
radial wear rate of a grain number of loading cycles coefficient of thermomechanical fatigue temperature of a sample
2. Methodology and materials of the research To research the fatigue strength of abrasive grains the following work materials were chosen: steel 45, 40Kh, 40KhN, 38KhGN, 12KhN3A, 12Kh18N10T. All the samples went through heat treatment corresponding to the grinding operations. Tests were held on the sample which was heated in advance up to the following temperatures 20, 200, 400, 600 ºС. Five repeats for each temperature were held. The most comfortable microcutting method to carry out tests is formed alumina shown on fig. 1a, which is got by extrusion of a specially made charge with the following high temperature sintering. Formed alumina is similar to white alumina in crystalline and chemical form. Single grains were set in a special arbor (fig. 1b) with a screwed shank. Then the grains set into the arbor were grinded on the 4th coordinated sharpening fixture that allows forming a wedge angle of 90º on the grain [12]. In order to run tests of abrasive grains under the action of cyclic thermal stress, a special microcutting test bed on the basis of face grinding machine 3G71 was developed. A special metal disk was put on the machine, imitating the grinding wheel (fig.1 c) in circumference of which an arbor was twisted with a single abrasive grain (fig.1 d). The necessary temperature of the sample was achieved by its heating with the gas burner. The sample temperature was controlled by a portable pyrometer PP-1. Cutting depth was 0,01mm constantly.
Fig. 1. Equipment of microcutting test bed: a) formed alumina; b) an edged grain in arbour; c) steel disk, imitating a grinding wheel with arbor
D.V. Ardashev / Procedia Engineering 206 (2017) 1044–1048 D.V. Ardashev / Procedia Engineering 00 (2017) 000–000
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Coefficient of thermomechanical fatigue calculated by means of formula:
kf
y n
(1)
The fact that grinding with the stride of single grain is imitated in this research helps to minimize the influence of physicochemical abrasive and work material on the grains wear rate. Every following contact of a single grain with the work material occurs on the preform surface but not on the track of the preceding abrasive grain. Thus it occurs on reaction products of the abrasive and work material. This allows excluding the influence of other types of wear if not fully then to at least minimize their influence. 3. Research results Figure 2 presents the photographs of single grains after contact with different steel and also formed marks on the work surface. The photographs are made with the help of digital camera system and microscope MBS-9. Measurement results of indexes of grain interaction with work material are given in table 1 and picture 3. The wear of the abrasive grains and thermomechanical fatigue coefficient were counted while repeating tests three-times in every temperature sample. Table 1. Tests results Index
Radial wear y, mm
Quantity of loading cycles n, nm
Coefficient of thermomechanical fatigue kf ·10–3
Steel make
Temp T, degr.
45
21
0,015
200
40Kh
40KhN
38KhGN
12KhN3A
12Kh18N10T
0,019
0,017
0,018
0,021
0,015
0,016
0,016
0,018
0,015
0,016
0,015
400
0,016
0,013
0,015
0,012
0,018
0,016
600
0,015
0,011
0,014
0,010
0,019
0,019
800
0,015
0,011
0,014
0,013
0,014
0,019
–
60
65
60
90
50
60
Index magnitude
21
0,250
0,292
0,283
0,200
0,420
0,250
200
0,266
0,246
0,300
0,166
0,320
0,250
400
0,266
0,200
0,250
0,133
0,360
0,266
600
0,250
0,169
0,233
0,111
0,380
0,316
800
0,250
0,169
0,233
0,144
0,280
0,316
It is necessary to pay attention to the uniqueness of the dependence character of the thermomechanical fatigue coefficient of white alumina on the make of grinding steel and its temperature for steel of the similar composition: with more carbon content and little amount of alloy elements – chromium, nickel, titanium (40Kh, 40KhN, 38KhGN) and low-carbon alloyed by chromium, nickel, titanium (12KhN3A and 12Kh18N10T). The characteristic points for all the testing materials are temperatures of 200 and 600 degrees. In these points the real change of the magnitude of thermomechanical fatigue coefficient occurs. Consequently there is the change of the intensity of submersion of abrasive grains of white alumina. The gradual decrease of the abrasive grain wear is the characteristic feature of the first group of materials with the increase of temperature of grinding material. This decrease is seen when the temperature of steel changes from 200 to 600 degrees. When heating the working sample more than 600 degrees the coefficient of thermomechanical fatigue is on the same level for steel 40Kh и 40KhN and increases quickly for steel 38KhGN.
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The character of intensity changing of the abrasive grains wear from white alumina while working the second group of materials – high-alloy steel – is similar: the change of concentration of nickel and titanium changes only the intensity magnitude in 1,5 times.
Fig. 2. Formed marks and single abrasive grains after tests (200 ºС): steel 40Kh; b) steel 40KhN; c) 38KhGN; d) 12KhN3A; e) 12Kh18N10T.
Fig. 3. Dependence of the coefficient of abrasive grain thermomechanical fatigue on the make of grinding steel and its temperature 1 – 12KhN3A; 2 – 12Kh18N10T; 3 – 40KhN; 4 – 45; 5 – 40Kh; 6 – 38KhGN
4. Conclusion 1. The offered methodology of grain wear tests by microcutting helps to get the information about their working capacity while grinding different makes of steel and alloys using different temperatures in process zone.
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2. The coefficients of thermomechanical fatigue which are counted in our experiment will allow considering the fatigue mechanism of abrasive grain wear when developing the integrated model of wear of the grinding wheel [13-15]. 3. The offered methodology of the estimation of abrasive grain working capacity in changing technological conditions let us evaluate the effectiveness of different technological operations [16-18] which deal with the increase of grinding operation effectiveness. The present methodology helps to develop the existing approaches to making the grinding operations [19-21] and the machining of new materials [22,23]. Acknowledgements South Ural State University is grateful for financial support of the Ministry of Education and Science of the Russian Federation (grant No 9.5589.2017/ВР). References [1] D.V. Ardashev, Physicochemical wear of abrasive grains during grinding processes, Journal of Friction and Wear. 4 (2014) 284–289. [2] D.V. Ardashev, Predicting the Physicochemical Wear of an Abrasive Grain in Grinding, Russian Engineering Research. 35 (2015) 394–397. [3] S. Yossifon, C. Rubenstein, Wheel wear when grinding workpieces exhibiting high adhesion, International Journal of Machine Tool Design and Research. 22 (1982) 159–176. [4] S.J. Deutsch, Analysis of mechanical wear during grinding by empirical-stochastic models, Wear. 29 (1974) 247–257. [5] R. Neugebauer, K.-U. Hess, S. Gleich, S. Pop, Reducing tool wear in abrasive cutting, International Journal of Machine Tools & Manufacture. 45 (2005) 1120–1123. [6] M.P. Hitchiner, J. Wilks, Some remarks on the chemical wear of diamond and cubic BN during turning and grinding, Wear. 114 (1987) 327– 338. [7] Z. Shi, S. Malkin, Wear of Electroplated CBN Grinding Wheels, Journal of manufacturing science and engineering. 1 (2006) 110–118. [8] K. Wegener, H.-W. Hoffmeister, B. Karpuschewski, F. Kuster, W.-C. Hahmann, M. Rabiey, Conditioning and monitoring of grinding wheels, CIRP Annals. Manufacturing Technology. 60 (2011) 757–777. [9] С. Bao, Y. Song, S. Hou, X. Yang, J. Yang, W. Yao, Effect of the cBN grit surface oxidation on grinding performance of the vitrified cBN tool, Journal of Xi'an Jiaotong University. 49 (2015) 124–129. [10] W. Graham, C.M. Voutsadopoulos, Fracture wear of grinding wheels, International Journal of Machine Tool Design and Research. 18 (1978) 95–103. [11] S.K. Bhattacharyya, V.L. Moffatt, Characteristics of micro wheel wear in grinding, International Journal of Machine Tool Design and Research. 16 (1976) 325–334. [12] S.N. Korchak, The productivity of the grinding of steel parts, Mashinostroenie, Moscow, 1974. [13] D.V. Ardashev, Definition of Abrasive Grain Wear upon Grinding from the Standpoint of the Kinetic Theory of Strength, Journal of Friction and Wear. 36 (2015) 266–272. [14] D.V. Ardashev, Mathematic Model of a Blunting Area of an Abrasive Grain in Grinding Processes, with Account Different Wear Mechanisms, Procedia Engineering. 129 (2015) 500–504. [15] D.V. Ardashev, Recursive Model of the Blunting of an Abrasive Grain, Russian Engineering Research. 36 (2016) 781–783. [16] A.M. Kozlov, A.A. Kozlov, Shaping the surface topology of cylindrical components by means of an abrasive tool, Russian Engineering Research. 29 (2009) 743–746. [17] A.M. Kozlov, A.A. Kozlov, Y.V. Vasilenko, Modeling a Cylindrical Surface Machined by a Non-circular Face Tool, Procedia Engineering. 150 (2016) 1081–1088. [18] A.V. Tyuhta, Y.V. Vasilenko, A.M. Kozlov, Ways to Enhance Environmental Flat Grinding by Improving the Technology of the Coolant Supply, Procedia Engineering. 150 (2016) 1073–1080. [19] I.V. Shmidt, A.A. Dyakonov, Forming effective cycle of round grinding with radial feed, Key Engineering Materials. 685 (2016) 360–364. [20] L.V. Shipulin, A.A. D’yakonov, Imitation Model of Forecasting Surface Relief When Forming it During Cylindrical Grinding, Procedia Engineering, 150 (2016) 936–941. [21] A.A. D`yakonov, L.V. Shipulin, Wheel–workpiece interaction in peripheral surface grinding, Russian Engineering Research. 36 (2016) 63– 66. [22] I.V. Shmidt, A.A. Dyakonov, Stress state of parts coated with polymer composite materials during machining, Mechanics of Composite Materials. 51 (2015) 199–208. [23] I.V. Shmidt, A.A. Dyakonov, Finishing of laminar systems, Russian Engineering Research. 34 (2014) 822–825.