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Научни трудове на Съюза на учените в България - Пловдив Серия В. Техника и технологии, том XIII., Съюз на учените, сесия 5 - 6 ноември 2015 Scientific Works of the Union of Scientists in Bulgaria-Plovdiv, series C. Technics and Technologies, Vol. XIII., Union of Scientists, ISSN 1311-9419, Session 5 - 6 November 2015.
RESEARCH SEVERITY PARAMETERS DURING PROCESSING MILLING WITH CHANGES IN THE DIRECTION OF MILLS
Bejtulla Krasniqi1*;Avdi Salihu2; Hakif Zeqiri2; Ahmet Latifi2
1.Ntsh''Krasniqi' ' GJILAN KOSOVO , 2.University of Mitrovica''I SA BULETINI'' KOSOVO
Abstract
In themetalprocessingindustryproduction machinesformetalcuttingprocessingof particular importance isthe requirementfor the qualityand accuracy ofthe work surfacein order to increasethetimeinthe carservice equipment.To achievehighqualitysurfacesmade, needto know thekey factorsthat influence theseverityoftheprocessedsurface(micro raised orundulations).Qualitysurfacesmadeupofanumberof factors, whichamong themselvesare closelyconnectedwiththeprocessingconditions, such asprocessingmode, coolingmode, lubrication, drivingstability, workingthe materialmicrostructure, cuttingtoolgeometryetc. From the results obtained experimental research severity parameters during milling processing with the change of direction of the milling, the RSt 37-2 stainless steel material according to DIN greatest impact has the of cuting depth (d),cutting feed (f ) and the cutting speed (v). However,thispaperisintendedto describe the analysis of the results obtained, we conclude that the change of regimes sizes processing parameters vary parameters of severity. There fore, optimization of processing regimes obtained better results roughness parameters Ra, Rt and Rz, butthere areother parameterswhicheditabilityimpact oncuttingmaterialsandthe quality oftheprocessedsurface, so it is proposed thatinthe futuretoexplorethedefinitionofother importantfactorsfor evaluating theprocessingof materialsby cutting.
Keywords
Processingwithcutting, Milling,Mills, Severity ofparameters,Referencelength,impact offactors, Quality surfaces
l.Introduction
The purposeof the paper isthe severity ofexperimentalresearchwork surfaceduring processingbyreamingtochangethe directionofmillingfor steelRSt37-2according toDIN.All the characteristicsof processing(cutting regimesused),factorsinfluencingtheseverity ofthisstainless steelsurface,the realization of the experimentmeasurements, mathematical modelsand analysis of resultsare givenin the relevant chapters,and thereforenotpresentedat the entranceof the paper. 232
5.0. Conditions of conducting experiment
Researchseverityduring processingparameterswithreamingtochangethedirection of themillingis examined materialofsteelRST37-2under (DIN s). It iswithdimensions(120 x60x20) mm.The sampleis processedinuniversal milling machinUWFKnuthGermanmanufacturingCompanywhich is locatedinlaboratoryFATSin Mitrovica, whichisshown in Figure5. 1.
Sampleprocessingisusedmillingwithstaggeredteethsymbolizedbythemanufacturersstandard885A Dinandisusingcutting toolholder40X27X63TGL2969/0316.Measurement
ofsurfaceseverittyparametersismadeelaboratecomputerdevicefor
measuringtheseverityTALYSURFintraof the companyTAYLORHOBSON, shownin Figure5.5.
Fig. 5.1. Machinewithwhich it is madethe Fig. 5.5. Measuringdevicefor measuring the realization ofthesamplepreparationseverity oftheprocessedsurfaceTALYSURF (FATS-Mitrovica).-Intra (FATS-Mitrovica)
Table6.4. Characteristics ofcuttingregimesand the level ofcodeused
CHARACTERISTICS OFINDEPENDENT VARIABLE SIZES
Nr. sizes levelcode maximum average minimum
1 0 -1
1. v [m/min] Xi 213.52 169.56 124.34
2. f [mm/min] X2 65 40 24
3. d [mm] X3 0.6 0.4 0.2
Table6.5. Plancodedmatrixoffirst orderwiththreefactors
Nr. Codinglevels Ra[^m] lnRa[^m] Values calculated Ra M
X0 X1 X2 X3
1 1 124.34 24 0.2 0.2254 -1.4898 0.258
2 1 213.52 24 0.2 0.2451 -1.4060 0.239
3 1 124.34 65 0.2 0.2874 -1.2468 0.301
4 1 213.52 65 0.2 0.2789 -1.2769 0.280
5 1 124.34 24 0.6 0.3500 -1.0498 0.335
6 1 213.52 24 0.6 0.2833 -1.2612 0.311
7 1 124.34 65 0.6 0.3830 -0.9597 0.392
8 1 213.52 65 0.6 0.3338 -1.0972 0.364
9 1 169.56 40 0.4 0.3385 -1.0832 0.316
10 1 169.56 40 0.4 0.3373 -1.0867 0.316
11 1 169.56 40 0.4 0.3112 -1.1673 0.316
12 1 169.56 40 0.4 0.3370 -1.0876 0.316
Mathematicalmodelisgiveninthisform:
R C kv fkf dkd R=C„-v -i -d R
(4.2)
Based on the resultsgiven in table6.5,usingscientificmethodsreferredtoexperimentand basedon theperformanceofchapter4,calculatedvalues ofconstantsandcoefficients ofa mathematicalmodel:
R =0.444- v-01365 ■ f 0 1569 ■ d 02392 (6.13)
Graphicinterpretationofa mathematicalmodel(6.13 )deviationsof averageroughnesRa[^m] isshown in figure6.9.
theprofilearithmetic
V=213.52[m/minl
Ra[(imm]
"'-^[pinm]
BWH
f [mm/min]
f [.mm/min]
V=169.56lm/minl
d[mm]
V=124.34[m
Ra[(im:
f[mm/min]
Birt» HSurt'irifii'Jk tsnAninvct .'mr.u»H
mm]- .
jk fli w« m m « * « * 4i i*m
d[mm]
Fig.6.9.Graphicinterpretationofa mathematicalFig.27. Graphicinterpretationis given, iemodelthe diagram ofprofilegraphsforthe first
experiment
7.0. Analysis of results
On the basis of results obtained experimentally mathematical model for research and graphic interpretation of the parameters of severity during processing by reaming to change the direction of the milling to RSt 37-2 stainless steel material according to DIN standard, is shown the impact of processing regimes for implementation the experiment: cutting speed, cutting feed, and cutting depth. For this research is mathematical statistical methods used by many factors Y= 2k + No, where all factors dependent variable (output), are given in the form of exponential function of the independent variables.Numerical values obtained by mathematical models with reaming the opposite direction and Milling with reaming-way:
Milling withtheopposite directionMillingwithreaming-way
By comparing the results obtained on the basis of numerical values for the experiment conducted research severity parameters Ra, Rt and Rz during processing by reaming with the change of direction that milling, drawn conclusions that the experiment conducted by reaming the opposite direction were obtained better results severity parameters comparing the results obtained with reaming-way
8.0. Conclusion
Based on the research results obtained for the parameters of severity during processing with milling to change the direction of milling,the RSt 37-2 stainless steel material according to DIN standard mathematical model analysis of many factors, graphic interpretation is presented impact factors used in the experiment.Realization of the experiment and analytical calculations and the use of literature so far, show the complexity and the conditions in which is the process of cutting and necessity define the surface severity of the milling process, the mathematical model is presented,which has foreseeable changes in physical phenomena and technological effects,processing.Fromwhat has been saidearlier cutting depth conclude thatcuttingisthe parameterthathas the mostimpact on theseverityof surfacesprocessedinthis research.Reason earned this result is that the first experiment was conducted with milling with opposite direction and milling reaming-way.On the basis of this research is important to emphasize that the biggest impact of the stakeholders in the area of processed severity depends on many factors that are associated with the processing conditions influence the severity parameters appear:the type of processing, cutting regime,geometry of the instrument,tool cooling and lubericant,rigidity of the material processing system settings etc. So it is proposed thatinthe futuretoexplorethedefinitionofother importantfactorsfor evaluating theprocessingof materialsby cutting.
9. References
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Ra=0.444- v-Rt=2.736- v-Rz=3.016- v"
-0.1365
,-0.0802
-0.1971
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