Research of the horizontal parameters of the roughness machined surface by turning.

Salihu, Avdi ; Zeqiri, Hakif ; Bunjaku, Avdyl 等

1. INTRODUCTION

Process of processing with cutting is done with the purpose to obtain parts with determined characteristics. From the quality of processing part are depended also the exploiting features of the whole construction in which is the part fixed. The surface of the parts is defined in macro plan with the tolerance of the form and position. The surface roughness is reviewed in micro plan, that is shown as a union of very small prominence of the real surface in agreement defined as profile deviation of the surface from the accepted line in the limits of elementary length, wherein is reviewed the deviation of the form and waving. The description of it is done through parameters wherein are classified in three groups. The first group includes permanent parameters wherein are included parameters of height ,horizontal planimetrical and spotted parameters. The second group includes functional parameters of profile and roughness, whereas the third group includes functional parameters of roughness profile (Bushati & Milton, 2005).

In this work are shown experimental researched results for horizontal parameters and that the change of average distance of the tops s and average distance of roughness sm (fig.1) in dependence of the cutting speed v, cutting depth, cutting feed as well as the nose radius r.

[FIGURE 1 OMITTED]

2. CONDITIONS FOR EXPERIMENT REALIZATION

Machine: The experiments for measurement of roughness of the surface process are realized by numeric lathe model MD 5S GILDEMEISTER P = (1.85-25) kW with rotating nr. fields n=(100-4000) rev/min and feed (0.001-39.99) mm/rev

Metal cutting instrument: The cutting inserts: SNGN 120708 -120712-120720 from mixed ceramic ( Al [sub.2][O.sub.3] + TiC) of

HERTELL company are used. Also, the tool holder is used CSRNR 25x25 M12H3 that the cutting edge obtains these values: [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII].

Measure device: Measurement of parameters of the roughness on the processed surface is done with the computer measurement equipment Talasurf 6 of Taylor Hobson Company.

Research material: The rings are made of machined steel C45 (pursuant to DIN) in normal state with strength in limits of 185-200 HB with dimensions [??] 170 x 80 x 25 mm.

Processing parameters: The research process is realized with the change of v, s, a and r presented in tab.1 using the plan with many factors of the first row ([2.sup. 4] + 4 ) (Stankov, 1982).

3. ANALYSE OF THE RESEARCH RESULTS

The obtained results during the realization of the experiment and the solution of the plan are shown in tab. 2. After processing the data there are obtained the mathematical models 1 and 2 (Salihu, 2001).

The graphic interpretation of mathematical models is shown in fig 2 and 3. By analyzing the mathematical models and graphic interpretations it is seen that the speed increase influences in average distance sm and average distance s. Then with the increase of nose radius it is also increased average distance of roughness sm whereas there are reduced distances of tops of profiles s.

With the increase of cutting feed and cutting depth there are increased parameters sm and s.

[s.sub.m] = 1394 .978 [v.sup. - 0 0695] [s.sup. 0 947] [a.sup. 0.0146] [r.sup. 0 0211] (1)

s = 2608 .121 [v.sup. - 0 098] [s.sup. 1.717] [a.sup. 0 078] [r.sup. - 0 4431] (2)

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

4. CONCLUSION

The analyses of the mathematic models obtained make us possible to conclude:

--the change of the parameters in the function of cutting parameters can be represented in step function

--influence in increase of parameters s and sm have cutting feed and cutting depth.

--nose radius has influence in increase of sm whereas in reduction of s.

--the influence of speed influences in reduction of horizontal parameters

The results of the research are of the interest to show the exploited characteristics in the surface lay by choosing the cutting parameters.

5. REFERENCES

Bushati, A. (1975). Mechanical technology, volume I (Teknologjia mekanike), dispenca I, Faculty of mechanical engineering, Tirane

Milton C. Shaw (2005). Metal cutting principles, Arizona state University, ISBN 0-19-514206-3, Oxford, New York

Salihu, A. (2001). Research of machinability of cutting material with increased speed Hulumtimi i perpunueshmerise se materialit me prerje me shpejtesi te rritura), doctoral dissertation, Faculty of mechanical Engineering, Prishtine

Stankov, J. (1982). Measurement technical basic, methods and experiments planning (Osnove merne tehnike, metode planiranja eksperimenata), FTN, Novi Sad

Tab. 1. Characteristics of the factors

Nr Note Level Maximal average Minimal
 Code 1 0 -1

1 v (m/min) X1 700,000 458,258 300,000
2 s (mm/rev) X2 0.400 0,283 0,200
3 a (mm) X3 1,600 0,894 0,500
4 r (mm) X4 2,000 1,265 0,800

Tab. 2. Results of the experiment

 REAL PLAN OF MATRIX

Nr v s a r
 (m/min) (mm/rev) (mm) (mm)

1 300.000 0.200 0.500 0.800
2 700.000 0.200 0.500 0.800
3 300.000 0.400 0.500 0.800
4 700.000 0.400 0.500 0.800
5 300.000 0.200 1.600 0.800
6 700.000 0.200 1.600 0.800
7 300.000 0.400 1.600 0.800
8 700.000 0.400 1.600 0.800
9 300.000 0.200 0.500 2.000
10 700.000 0.200 0.500 2.000
11 300.000 0.400 0.500 2.000
12 700.000 0.400 0.500 2.000
13 300.000 0.200 1.600 2.000
14 700.000 0.200 1.600 2.000
15 300.000 0.400 1.600 2.000
16 700.000 0.400 1.600 2.000
17 458.258 0.283 0.894 1.265
18 458,258 0.283 0.894 1.265
19 458.258 0.283 0.894 1.265
20 458.258 0.283 0.894 1.265

 RESULTS

Nr Sm S
 ([micro]m) ([micro]m)

1 200.670 111.670
2 181.670 53.670
3 408.330 392.330
4 357.670 359.330
5 201.000 136.330
6 178.000 63.000
7 405.000 406.330
8 363.670 228.330
9 199.670 51.330
10 178.660 65.000
11 408.000 171.660
12 365.330 189.660
13 194.330 86.000
14 242.330 76.670
15 363.330 100.330
16 360.000 361.670
17 311.000 215.000
18 290.000 189.000
19 287.000 210.000
20 282.000 222.000