Mica Hybrid Composites

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ScienceDirect Materials Today: Proceedings 16 (2019) 808–815

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ICAMMAS17

An Experimental Investigation of Drilling Al/Sic/Mica Hybrid Composites *

S.Senthil babu a, B.K.Vinayagam b, M.Yogeshwaranc a

Assistant Professor – Mechanical, Valliammai Engineering College. Research Scholar, SRM University, Chennai b Professor – Mechatronics, SME, SRM University, Chennai c PG Scholar - Mechanical, Valliammai Engineering College, Chennai.

Abstract

These days’ composites are finding wide application in all fields of Engineering because of their better properties. Drilling is the most generally perceived machining operation performed on composites and the quality of drilled hole has an imperative bearing. This paper analyses the microscopic and SEM images of the specimen surface and explores the impact of various drilling parameters on the thrust force induced and the roughness of drilled hole surface in drilling Al/Sic/Mica hybrid composites. The tests were carried out on a Vertical machining centre utilizing LMT Onsrud Solid Carbide 8 Facet uncoated Drills of diameter 5mm, 7.5mm and 10mm. Response surface methodology is used to develop mathematical models to predict the drilling thrust force and the surface roughness of the drilled holes in terms of various drilling parameters. The drilling parameters considered for the analysis are spindle speed, feed rate and drilling tool diameter. The outcomes demonstrated that the created model can be viably utilized for the forecast of drilling force and surface roughness of the holes drilled in the hybrid composites considered. © 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Advances in Materials, Manufacturing and Applied Sciences. Keywords: Hybrid composites; 8 facet drill; Response surface methodology; Mathematical model.

1. Introduction The likelihood of exploiting specific properties of the constituent materials to meet specific requests is the most critical inspiration for the advancement of composites. Composite is a materials framework made out of two or more physically particular stages whose blend produces total properties that are not the same as those of its constituents. Metal matrix composites (MMCs) have fundamentally enhanced properties including high specific quality; specific modulus, damping limit and great wear resistance contrasted with unreinforced alloys.

* Corresponding author. Tel.: +91-9884206878; E-mail address: [email protected] 2214-7853 © 2019 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Advances in Materials, Manufacturing and Applied Sciences.

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The expansion of consumer requirements for quality metal cutting related items has driven the metal cutting industry to constantly enhance quality control of metal cutting procedures [1]. Surface roughness which is utilized to decide and assess the nature of an item is one of the significant quality properties of an end-milled item. So as to acquire better surface roughness, the correct setting of cutting parameters is critical before the procedure happens. As a beginning stage for deciding cutting parameters, technologists could utilize the hands on information tables that are outfitted in machining information handbooks [2]. Surface roughness assumes a noteworthy part in the execution of exactness machines. Roughness is ordinarily measured by a stylus instrument that opens up and records the vertical movements of a stylus as it moves at a consistent speed over the surface to be measured. For delicate surfaces, be that as it may, non-reaching procedures, for example, optical strategies are best Drilling is frequently utilized in commercial enterprises attributable to the requirement for component assembly in mechanical structures. Numerous researchers reported that the nature of the drilled surfaces depend firmly on the geometry of the tool, drilling parameters and tool material [3]. A wrong determination of these parameters can prompt material degradations. Drilling of MMCs stance numerous issues to the fabricating designers, for example, high drilling forces, tool wear, and burr. The drilling procedure in MMCs for picking appropriate tool material and creating quality holes [4]. The mechanics of drilling composite materials has been contemplated alongside the nature of the holes and the impacts of tool geometry and tool material. Numerous researchers have contemplated the drilling and turning attributes of ceramic reinforced composites [5], [6]. This paper examines the impact of various drilling parameters on Thrust force in drilling Al/Sic/Mica hybrid composites and surface roughness of the drilled holes. The analyses were directed on a CNC Vertical machining centres utilizing Multifaceted (LMT Onsrud Solid Carbide 8 Facet uncoated Drills) drills of diameter 5mm, 7.5mm and 10mm. Response surface model is created to relate the thrust force and surface roughness for various drilling parameters. The machining parameters considered for the tests are spindle speed, feed rate, and drill diameters. The outcomes demonstrated that the created model can be adequately utilized for the forecast of Thrust forces and surface roughness in drilling of Al/Sic/Mica hybrid composites. 2. Experimentation 2.1. Specimen Preparation Stir casting strategy is utilized to prepare the specimen for our examinations. It is a fluid state strategy for composite making, in which the softening was done in a graphite crucible. Scraps of aluminum alloy (Al6061) were preheated at 450°C for 3 hours [7]. Then the furnace temperature was raised over the liquidus temperature to soften the alloy scraps totally and afterward preheated strengthening materials (10% of particulate silicon carbide of size 40µm and 5% of mica powder) are included and blended completely with a liquid matrix metal. The molten slurry is poured into a preheated rectangular mould and allowed into solidify as shown in Fig 1.. The solidified casting is machined to our required size of 100mm x 100mm x 10mm. 2.2. Microstructure Study For microstructural study, specimens were cut from the cast. The Microstructure was imaged with a Dewinter optical microscope instrument. Microstructure was used to characterize the distributions of the material [8]. Microstructure are taken under a magnification of 150x and the etchant used is kellar Reagent Hydro fluoric solution. Fig 1 Shows the polished matrix of metal matrix composite surface at 100X magnifications. The matrix shows the particles of composite SiC is uniformly distributed. While the particles of SiC are finer and the mica particles are larger and present as lump in metal matrix. The SiC particles occupied the grain boundary which is seen as thin grain boundaries as the matrix is not etched. Fig 2 shows the microscopic image at 200X magnifications and the mica particles are more present in the metal matrix Fig 3 shows the clear thick grain boundaries after etching with kellar’s reagent soln. the grain boundaries showed the occupied SiC particles in it. Some particles also distributed in the matrix. The black round particles are Mg2Si eutectic particles precipitated in primary alpha aluminium solid solution. The mica particles are distributed in metal matrix.

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Fig. 1. Optical micrograph as polished at 100X

Fig. 3. Optical micrograph as etched at 100X

Fig. 2. Optical micrograph as polished at 200X

Fig. 4. Optical micrograph as etched at 200X

Fig 4 shows the microstructure at 200X which resolved the grain boundaries of primary aluminium matrix. The SiC have occupied the grain boundary voids whereas the mica particles present along with Mg2Si in metal matrix. 2.3. SEM Analysis For the micro structural studies, specimens were cut from cast and then mechanically polished into good finish. Reinforcement morphology and its distribution in the metal matrix along with other intrinsic micro structural features were identified by examining the samples in a EVO HD 15 ZEISS Germany make Scanning Electron Microscope (SEM).

Fig. 5. SEM image of the composition at 300X

Fig. 6. SEM image of the composition at 1000X

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Fig. 5 shows the SEM image of the specimen surface under a magnification of 300X. The effect of addition of mica in the metal matrix produced very fine surface with mica particles projected at the surface as fine particles and effected the fine finish. Fig. 6 shows the same image, but at higher magnification of 1000X. the fine surface finish produced by the process is established. Some embedded particles of SiC could be seen in the matrix as black particles at the track surface

Fig. 7. SEM image of drilled hole surface at 300X

Fig. 8. SEM image of drilled hole surface at 1000X

Fig. 7 shows the drilled surface of the bore by multi-faceted drill. The bore surface shows the SiC particles in the metal matrix embedded and projected out. The debris of the particles of base metal aluminium alloy are lower in the surface. The drill has not produced any consistent tracks but has produced high surface finished surface without any independent tracks. No crest and troughs observed in the metal matrix. The particles of SiC are uniformly distributed on the bore surface and the drilling operations has brought SiC particles to the surface. The SiC particles have fragmented to smaller size. The particles of mica completely covered with metal matrix and at some areas the particles appear at the surface which is measured as 10 microns. Fig 8 shows the surface resolved by SEM at 1000X magnification. The track is free from fissures and shows the plastic deformation of the metal matrix. The particles of mica are not seen as they seemed to have covered by the metal matrix by plastic deformation. 2.4. Drilling Experiments In our study, the drilling tests were led on a Vertical CNC machining centre utilizing Solid carbide 8 facet uncoated drills of diameter 5mm, 7.5mm and 10mm under various spindle speeds of 1000, 2000 and 3000 rpm and for various feed rates of 0.05, 0.10, 0.15 mm/rev. The 8 facet solid carbide tools used in our experiments. To enhance the viability, the analyses were directed according to the L27 orthogonal array as shown in Table I. The PC controlled data acquisition system was utilized to gather and record the data amid investigations. The Kistler dynamometer was utilized to record the thrust forces amid drilling operation [9]. Another reaction parameter, Drilled hole surface Roughness is measured by utilizing Surface Roughness Tester at Kosaka labs, Chennai. 3. Modelling And Analysis For examination, Response surface methodology is utilized, which is a social event of test techniques, truthful and numerical frameworks that are useful for the examination of issues in which the response of interest is affected by various parameters and the objective is quality improvement and to minimize the response parameter [10]. Design expert-7 sotware is used to apply response surface methodology and to fit the trial data to the second order polynomial [11].

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.Table 1. Drilling Experimental Results Test No

Responses Drilling Parameters Drill dia A (mm)

Feed rate B (mm/rev)

Speed C (rpm)

Surface Roughness (µm)

Thrust force (N)

1

-1

-1

-1

2.720

155.694

2

-1

-1

0

2.464

120.834

3

-1

-1

1

2.231

95.86

4

-1

0

-1

3.297

201.468

5

-1

0

0

3.075

168.15

6

-1

0

1

2.786

132.204

7

-1

1

-1

4.274

248.128

8

-1

1

0

3.985

204.038

9

-1

1

1

3.718

174.32

10

0

-1

-1

2.765

175.384

11

0

-1

0

2.298

136.95

12

0

-1

1

1.865

103.632

13

0

0

-1

2.971

222.472

14

0

0

0

2.375

186.529

15

0

0

1

2.042

149.748

16

0

1

-1

3.596

268.61

17

0

1

0

3.308

235.589

18

0

1

1

3.008

198.15

19

1

-1

-1

2.742

201.642

20

1

-1

0

2.426

167.01

21

1

-1

1

2.156

133.062

22

1

0

-1

2.908

248.346

23

1

0

0

2.453

213.965

24

1

0

1

2.264

179.42

25

1

1

-1

3.452

296.02

26

1

1

0

3.119

261.798

27

1

1

1

2.936

226.782

The final regression equation for the response factor surface roughness of the drilled hole is given below. Surface Roughness = 2.49 - 0.23 A + 0.54B - 0.32C - 0.20AB - 0.016AC + 0.026BC + 0.25A2 + 0.26B2 + 0.040C2. (1) Regression equation for the response factor, Thrust force is given as Thrust force = 185.60 + 23.74A + 45.74B - 34.70C + 2.40AB - 0.32AC - 1.11BC + 4.15A2 - 0.061B2 + 1.18C2 (2)

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From the mathematical models in equations (1) and (2), the predicted values of surface roughness and the thrust force for all the tests were calculated and tabulated below in the Table2. Table 2. Actual And Predicted Values Test No

Response – Surface Roughness (µm)

Response – Thrust Force (N)

Actual

Predicted

Actual

Predicted

1

2.720

2.86

155.694

157.059

2

2.464

2.49

120.834

122.609

3

2.231

2.2

95.86

90.519

4

3.297

3.314

201.468

201.57

5

3.075

2.97

168.15

166.01

6

2.786

2.706

132.204

132.81

7

4.274

4.288

248.128

245.959

8

3.985

3.97

204.038

209.289

9

3.718

3.732

174.32

174.979

10

2.765

2.596

175.384

174.569

11

2.298

2.21

136.95

139.799

12

1.865

1.904

103.632

107.389

13

2.971

2.85

222.472

221.48

14

2.375

2.49

186.529

185.6

15

2.042

2.21

149.748

152.08

16

3.596

3.624

268.61

268.269

17

3.308

3.29

235.589

231.279

18

3.008

3.036

198.15

196.649

19

2.742

2.832

201.642

200.379

20

2.426

2.43

167.01

165.289

21

2.156

2.108

133.062

132.559

22

2.908

2.886

248.346

249.69

23

2.453

2.51

213.965

213.49

24

2.264

2.214

179.42

179.65

25

3.452

3.46

296.02

298.879

26

3.119

3.11

261.798

261.569

27

2.936

2.84

226.782

226.619

Fig. 9 and 10 show the graphs plotted between the actual experimental values and the predicted values from the formulated mathematical models for roughness and thrust force respectively.

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Actual vs Predicted values

4.5

Variable Actual Predicted

Variable Actual Predicted

300

4.0 Thrust Force in N

Roughness in µm

250 3.5

3.0

2.5

2.0

200

150

100 3

6

9

12 15 Expt No

18

21

24

27

3

Fig. 9. Actual vs Predicted values of roughness

6

9

12 15 Expt No

18

21

24

27

Fig. 10. Actual vs Predicted values of thrust force

Table 3. Response table for Means (Roughness) - Smaller is better

Level

Dia

Feed

Speed

1 2 3 Delta Rank

3.172 2.692 2.717 0.480 3

2.407 2.686 3.488 1.081 1

3.192 2.834 2.556 0.635 2

Table 4. Response table for Means (Thrust Force) - Smaller is better

Level

Dia

Feed

Speed

1 2 3 Delta Rank

166.7 186.3 214.2 47.5 3

143.3 189.1 234.8 91.5 1

224.2 188.3 154.8 69.4 2

Table. 3 shows that the feed rate have greatest influence on surface roughness of the drilled holes. The next influencing factor is spindle speed and then the drill tool diameter. Similarly, response table of means for thrust force is shown in table 4. For thrust force also, the feed rate is the most influencing factor, followed by spindle speed and drill tool diameter. The main effect plots for drilled hole surface roughness and the thrust force induced on drilling Al/Sic/Mica specimen when using 8 faceted uncoated solid carbide drills are shown in figs 11 & 12. Main Effects Plot for Means

Main Effects Plot for Means

Data Means

Data Means

Drill dia

3.50

Feed

Drill dia

3.25

200

2.75 2.50 5.0 3.50

7.5 Speed

10.0

0.05

0.10

0.15

3.25

Mean of Means

3.00

Mean of Means

Feed

225

175 150 5.0

7.5 Speed

10.0

1000

2000

3000

0.05

0.10

0.15

225 200

3.00

175

2.75 2.50

150 1000

2000

3000

Fig. 11. Main effect plots for Means For roughness

Fig. 12. Main effect plots for Means For Thrust force

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4. Conclusion In this experimental study, the optical microscopic and SEM images of the surface of the prepared specimen of Al/Sic/Mica hybrid composite and SEM images of the drilled hole surfaces using multifaceted uncoated solid carbide drills were studied. The investigations on the drilling performance of Al/Sic/Mica hybrid metal matrix composites using multifaceted uncoated solid carbide drills have been done and the following points were concluded. 1. Linear regression equations are developed to predict the values of drilled hole surface roughness and the thrust forces induced during drilling. 2. The predicted values are compared with measured values and are found to be in good agreement. 3. Through ANOVA, it is found that the most influencing drilling parameter to control the surface roughness and thrust forces is the feed rate, followed by the spindle speed drill tool diameter. Acknowledgements The authors would like to acknowledge the support of Valliammai Engineering College, Kattankulathur, Chennai, Anna University Chennai, Met Mech Lab, Chennai and Kosaca calibrations lab, Chennai. References [1] T.S. Mahesh Babu, N.Muthu Krishnan, “An experimental Investigation of turning Al/SiC/B4C Hybrid Metal Matrix Composites using ANOVA analysis”, Scholarly Journal of Engineering Research Vol. 1(2), pp. 25-31, May 2012 [2] N. Radhika, R. Subramanian, S. Venkat Prasat,”Tribological Behaviour of Aluminium/Alumina/Graphite Hybrid Metal Matrix Composite Using Taguchi’s Techniques,” Journal of Minerals & Materials Characterization & Engineering, Vol. 10, No.5, pp.427-443, 2011 [3] P. Kishore Kumar, K. Kishore, Laxminarayana ,”Prediction Of Thrust Force And Torque In Drilling On Aluminum 6061-T6 Alloy,” International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 3, March – 2013 pp 2278-0181. [4] Evren Kabakli, Melih Bayramoðlu, Necdet Geren, “Evaluation Of The Surface Roughness And Geometric Accuracies In A Drilling Process Using The Taguchi Analysis,” Materials and technology 48 (2014) 1, 91–98. [5] Dinesh Kumar, Jasmeet Singh, “Comparative Investigation of Mechanical Properties of Aluminium Based Hybrid Metal Matrix Composites,” International Journal of Engineering Research and Applications March 2014 2248-9622. [6] Alakesh Manna and Kanwaljeet Singh, “An Experimental Investigation on Drilled Hole Surface during Drilling of Al/SiC-MMC,” International Journal of Surface Engineering & Materials Technology, Vol. 1 No. 1 July-Dec. 2011, ISSN: 2249-7250. [7] Ajay Singh, Love Kumar, Mohit Chaudhary, Om Narayan, PallavSharma, Piyush Singh, Bhaskar Chandra Kandpal, Som Ashutosh, “Manufacturing Of Ammcs Using Stir Casting Process And Testing Its Mechanical Properties,” Int J Adv Engg Tech/IV/III/JulySept.,2013/26-29. [8] M.D.Antony Arul Prakash and M. Arockia Jaswin, “Microstructural Analysis of Aluminium Hybrid Metal Matrix Composites Developed Using Stir Casting Process,” International Journal of Advances in Engineering, 2015, 1(3), 333 - 339. [9] A. Munia Raj, Sushil Lal Das and K. Palanikumar, “Influence of Drill Geometry on Surface Roughness in Drilling of Al/SiC/Gr Hybrid Metal Matrix Composite,” Indian Journal of Science and Technology Vol 6 (7) | July 2013 0974-5645 [10] S. Madhavan, S. Balasivanadha Prabu, “Experimental investigation and Analysis of Thrust Force in Drilling of Carbon Fibre Reinforced Plastic Composites using Response Surface Methodology,” International Journal of Modern Engineering Research (IJMER), Vol.2, Issue.4, July-Aug. 2012 pp-2719-2723 [11] A.Arun premnath, T.Alwarsamy, T.Abhinav, C. Adithya Krishnakant, Suraface Roughness Prediction by Response Surface Methodology in Milling of Hybrid Aluminium Composites, International Conference on Modeling Optimization and Computing, Procedia Engineering 38 (2012) 745 – 752.