Elsevier Editorial System(tm) for Materials and Design Manuscript Draft Manuscript Number: Title: CUTTING FORCES IN TURNING OF GRAY CAST IRON USING SILICON NITRIDE BASE CUTTING TOOL Article Type: Original Paper Keywords: Silicon nitride, Cutting force, Gray cast iron. Corresponding Author: José Vitor Candido Souza, Ph. Corresponding Author's Institution: Instituto Nacional de Pesquisas Espaciais (INPE) First Author: José Vitor Candido Souza, Ph. Order of Authors: José Vitor Candido Souza, Ph.; Maria do Carmo Nono, PhD; Claudio Augusto Kelly, PhD; Marcos Valério Ribeiro, PhD; Olivério Moreira de Macedo Silva, PhD Abstract: This paper present the results of an experimental investigation on the effect of cutting forces on turning gray cast iron with silicon nitride (Si3N4) based ceramic tool. Turning experiments were carried out at five different cutting speeds and feed rates with depth of cut was kept constant. Tool performance was evaluated with respect to tool wear, temperature, surface finish produced and cutting forces generated during turning. The Si3N4 based ceramic cutting tool showed highter performance to increase cutting speed. These results can be associeted at good high temperature strength and contains graphite flakes in grey cast iron.

INPE - INSTITUTO NACIONAL DE PESQUISAS ESPACIAIS

S.J.Campos-SP, January, 16, 2007. Av. dos Astronautas,1.758 Jd. Granja CEP 12245-970 São José dos Campos - SP - Brasil Tel: 55-12-3945-6679 3945-6989 Fax: 55-12-3945-6717 To: Editor-in-Chief:

Professor K.L. Edwards

School of Engineering

University of Derby

Kedleston Road

Derby

DE22 1GB

UK Ref.: Submission of Manuscript to Materials & Design

Dear Professor Edwards,

We are pleased to submit our paper entitled “CUTTING FORCES IN TURNING OF

GRAY CAST IRON USING SILICON NITRIDE BASE CUTTING TOOL” for your

considerations. This is an original contribution for publication at Materials & Design.

My address for further correspondence is the following:

Prof. Dr. José Vitor C. de Souza

Av. dos Astronautas.1758,Jd. Granja – CEP: 12227-010 São José dos Campos –

SP.Brasil. Tel: 55 (12) 3945-6000 or 55-12-3945-6679

e-mail: vitor@las.inpe.br

Thank you once more for your attention.

sincerely yours,

José Vítor Cândido de Souza

Cover Letter

CUTTING FORCES IN TURNING OF GRAY CAST IRON USING SILICON NITRIDE BASE CUTTING TOOL

J.V.C. Souza1, M. C.A. Nono1, C. A. Kelly2 M. V.Ribeiro3, O.M.M. Silva4

1INPE - Av. dos Astronautas,1.758, S. J. Campo s - SP, CEP. 12245-970, Brazil

2FAENQUIL-DEMAR – Polo Urbo Industrial, Gleba AI-6, s/n, Lorena - SP, CEP. 12600-000, Brazil

3FEG-UNESP – Av.Ariberto Ferreira da Cunha, 333, Guaratinguetá – SP, CEP. 12516-410, Brazi

4CTA-IAE/AMR - Pça. Marechal do Ar Eduardo Gomes, 50, S. J. Campo s - SP, CEP. 12228-904, Brazil

vitor@las.inpe.br / candidojvc64@yahoo.com.br

Abstract

This paper present the results of an experimental investigation on the effect of

cutting forces on turning gray cast iron with silicon nitride (Si3N4) based ceramic tool.

Turning experiments were carried out at five different cutting speeds and feed rates with

depth of cut was kept constant. Tool performance was evaluated with respect to tool

wear, temperature, surface finish produced and cutting forces generated during turning.

The Si3N4 based ceramic cutting tool showed highter performance to increase cutting

speed. These results can be associeted at good high temperature strength and contains

graphite flakes in grey cast iron.

Keywords: Silicon nitride, Cutting force, Gray cast iron.

* Corresponding author. Tel.: +55 (12) 3945-6679, 39456989, FAX: +55 (12) 3945-6717

E-mail address: vitor@las.inpe.br / candidojvc64@yahoo.com.br (J.V.C. Souza).

Manuscript

1. Introduction

The term ceramics is applied to a range of inorganic materials of widely varying

uses. Generally these materials are non-metallic and in most cases have been treated at a

high temperature at some stage during manufacture. Ceramics are far less ductile than

metals and tend to fracture immediately when any attempt is made to deform them by

mechanical work [1]. They are often of complex chemical composition and their

structures may also be relatively complex.

Ceramics in recent years have been sought in many applications due to their

improved properties like good thermal shock resistance, good high temperature

strength, creep resistance, low density, high hardness and wear resistance, electrical

resistively, and better chemical resistance [2]. On the negative side, they feature low

ductility and fracture toughness at room temperature and standard pressure so that

fracture will occur once the atomic linkage forces are exceeded [2]. Therefore in

machining test using ceramic materials is a big challenge and quite expensive affair

because of their inherent brittleness. Recent work on the machining of compacted

graphite iron, Souza, 2004 has confirmed that brittleness of cutting tools ceramics can

be a big problem in the quality surface finish [3]. Cutting forces are widely recognized

as an optimum performance estimator of machining operations. Many authors, compiled

in the trend reports by Van Luttervelt et al. [2] and Ehman et al. [4], have addressed

their research work to the prediction and measurement of these forces. Both force

modulus and direction are directly related to different aspects of the removal process,

with a clear influence on the efficiency of the operation and the quality of the machined

part [5].

Thus, cutting force is result of the extreme conditions at the tool-workpiece

interface. This interaction can be directly related to the tool wear and, in the worst of the

cases, to the failure of the tool [6] and [7]. Consequently, tool wear and cutting forces

are related to each other, although that relationship is different for each different wear

mechanism (flank, crater, tool breakage). Cutting forces are also related with chatter and

process instability [7] and [8]. Chatter results in a loss accuracy of machined parts or in

damages of the machines structure.

In order to analyze the different situations that may arise during a machining

operation, in this paper the analysis utility, based on the simultaneous measurement of

the three orthogonal components of the cutting force (Fx, Fy, and Fz, measured with a

dynamometer and the current position of the tool in machining centre, is presented. The

performance of turning tests are a main step for turning optimization of gray cast iron.

In this paper was focus, three case studies will be shown. Process of manufacture

cutting tools, characterization and finally apply in turning tests. However it must be

remarked that the system has been developed only for running machining tests and

diagnostics, since in an industrial environment dynamometric devices such as the one

here used are not applied because of their high cost.

1.2. Machinability of gray cast iron

The presence of graphite particles in gray cast iron, renders this material to have

good machinability by nearly all criteria, especially when compared to steels. Low rates

of tool wear, high rates of metal removal, relatively low cutting forces and power

consumption are the characteristics of cast iron. The surface of the machined cast iron,

however, is rather matt in character. When machining gray cast iron the graphite

particles determine cutting forces and surface roughness while the matrix determines the

tool life [9] and [10].

When a steel part is replaced with ductile iron, better machinability is considered

to be the most important gain. Although there is no definite information in the published

literature that gray cast iron has better machinability than steels, data obtained from

manufacturers like General Motors shows that parts manufactured from gray cast iron

leads to improvement in tool life by 20–900% when compared to the heat treated forged

steels. Very fine surface finishes can be obtained on gray cast iron. For machining gray

cast iron, it is possible to find some practical cutting parameters value from the

machining handbook [11], [12] and [13].

1.3. Surface finish

One of the important parameters in evaluating the performance of a cutting tool is

the surface quality it produces on the machined work piece. It is well known in turning,

the surface quality largely depends upon the accuracy of replication of cutting nose on

the work surface. An ideal tool material is the one which can ensure high fidelity of its

nose replication, thereby ensuring good control over the surface quality [14]. The

advantage of machining using ceramic cutting tools is generally seen in higher levels of

surface finish obtained compared to that of other conventional tools such as cemented

carbides. While dimensional accuracy is controlled by flank wear of the turning tools,

the surface quality largely depends upon the stability of the cutting nose. Therefore the

variation of surface roughness with cutting speed it will be presented in this paper.

1.4. Influence of cutting force in the work material

The ceramic cutting tools have an advantage in the machining of hard work piece

materials. The variation of main cutting force with cutting speed on machining steel

(45HRC) using Ti[C,N] mixed alumina ceramic cutting tool is presented in paper [15].

In this paper it can be noted that the cutting forces of the ceramic cutting tool decrease

with cutting speed. The decrease of cutting force with respect to cutting speed when

using Ti[C,N] mixed alumina ceramic cutting tool shows that this type of ceramic

cutting tool can machine the work piece material with high speed and at low cutting

forces. The lower cutting forces result in a lower distortion of work piece [15], which

improves the surface finish while machining with the ceramic cutting tools.

In general the ceramic cutting tool materials produce good surface finish for

harder work piece materials. The surface finish of the work material improves with

cutting speed. Wuyi Chen et al. reported that surface finish was improved with

increasing cutting speed during machining medium hardened steel using CBN tools

[16]. It was reported that the ceramic tools exhibited superior performance as compared

to the carbide tools, especially at higher machining speeds, both in terms of tool life and

surface finish of the work-piece [17].

2. Materials and experimental procedure

The composition of Si3N4 ceramics were prepared 77.90Si3N4– 4.8Y2O3–

4.80CeO2–10.0AlN– 2.50Al2O3 (in wt.%) was produced and characterization. In this

work, they were produced using powders of α-Si3N4 (H.C. Starck, Germany,

d=3.2 g/cm3), α-Al2O3 (Alcoa Chemicals, Brazil, d=3.98 g/cm3), Y2O3 (H.C. Starck,

d=5.03 g/cm3), CeO2 (H.C. Starck, d=2.70 g/cm3) and AlN (H.C. Starck, d=3.26 g/cm3).

Suspensions comprising 100 g of appropriate powder mixture were prepared. The

suspensions were planetary-milled in an Al2O3 cube (i.e., milling container) for 3 h,

using 250 g of Si3N4 balls of different sizes. The weight loss of the Si3N4 balls and the

cube was always measured. The results indicated that the contamination level

introduced in this stage was <0.2 %. After drying (100 °C, 24 h), the powders were

sieved (100 mesh). Samples (16.36mm x 16.36mmx 7.5mm) were prepared by uniaxial

pressing (50 MPa) following by isostatic pressing (300 MPa, 2 min). The green samples

were embedded in a mixture of powders of Si3N4 and BN (70: 30 weight ratio) inside a

graphite crucible and sintered at 1850 °C for 2 h, in nitrogen atmosphere (0.1 MPa) with

a heating rate of 25 oC/min.

2.2. Characterizations

To remove any possible superficial layer formed at the surface of the samples

during sintering, the sintered samples were rectified and then polished until mirror

finishing at both sides. After cleaning in ultrasonic bath with acetone and then with

distilled water, the samples were stored in an oven of 100 °C to avoid water uptake from

atmospheric humidity.

Relative density of the samples after sintering was determined by Archimedes

method, correlating with the theoretical density of the mixtures. The weight loss was

determined by measurement of weight, before and after sintering. The phase

composition of the sintered samples was determined by X-ray diffraction analysis

(Phillips PW1380/80), using CuKα radiation, slow scanning and 0.02 °/s step. The

microstructures were observed by SEM investigations of polished surface after having

them chemically etched by molten NaOH/KOH mixtures at 500 °C for 5 min.

Hardness was determined by Vickers indentations under a load of 20 N, for 30 s.

Fracture toughness was calculated by the crack length emerging from the indentation

marks, using the equation proposed by Evans and Charles for Palmqvist shaped cracks

[18].

2.3. Cutting performance

All experiments were carried out on a computer numerical control (CNC) lathe

(Romi, Mod. Centur 30D) under dry cutting condition. The ceramic insert were cut and

ground to make SNGN120408 (12.7 mm×12.7 mm, 4.76 mm thickness, 0.08 mm nose

radius and 0.2 mm×20° chamfer) Fig.1.

Figire 1

A tool holder of CSRNR 2525 M 12CEA type (offset shank with 15° [75°] side

cutting edge angle, 0° insert normal clearance and 25 mm×25 mm×150 mm) was used

for the cutting experiments. The cutting performance of the silicon nitride base tools

was tested by machining gray cast iron. The Chemical composition and mechanical

properties of the gray cast iron were given in Table 1.

Table 1

The cutting tests for machining of gray cast iron were performed at a cutting

speed of 180, 240, 300, 360, 420 m/min with a feed rate of 0.12, 0.23, 0.33, 0.40, and

0.50 mm/rev and a constant depth of cut of 1.0 mm. The dimension of work material

was 105 mm in diameter and 300 mm in length. The wear of the tools was determined

by measuring the wear depth on the flank face by using a were measured using a

toolmakers microscope. To complete analysis of tool life was considered at finish

surface (Ra and Ry) using a surface roughness tester (Mitutoyo Surftest 402 series 178)

was adopted and to measure at temperature work-piece/cutting tools was used an

infrared pyrometer. Flank wear of 0.3 mm (ISO 3685) and variation abrupt of Ry has

been used as end tool life criterion. A three-force component analogue dynamometer

capable of measuring cutting forces during turning was utilized in test. A computer

connection for data acquisition was also made and calibrated. The analogue data can be

evaluated numerically on a computer and when required can be converted back to

analogue. A schematic illustration of measured forces is given in Fig. 2 [19].

Figire 2

The machining tests on grey cast iron work piece were chosen because the

ceramics are generally used to machine cast iron [20]. Grey cast iron contains graphite

flakes and it is widely used in the manufacturing industry [21].

3. Results

3.1. Properties of cutting tools

The relative density of the specimens after gas-pressure sintering process

presented values higher than 98.12 ± 0.14 % for this composition, demonstrating that

dense ceramics were obtained. Phase analysis by X-ray diffraction revealed only the

presence of β-Si3N4 indicating that the α-β-Si3N4 transformation has been completed

and, furthermore, that the additives formed an amorphous intergranular phase Fig.3.

Figire 3

The specimen investigated yielded ceramic materials of high hardness, more than

18.65 ± 0.15 GPa and the fracture toughness values are near to 5.96 ± 0.12 MPa m1/2.

These results can be attributed to several factors such as the high relative density, the

complete α-β-Si3N4 transformation, but mainly due to microstructural aspects Fig.4 [22

and 23].

Figire 4

The mass loss during the sintering was about 2.50 % sample. This behavior

demonstrates the viability of using Y2O3–CeO2–AlN–Al2O3 as sintering additive,

promoting important sintering activity for the composition. Thus, the sintering

parameters applied are adequate to produce ceramics cutting tools at high density.

3.2. Variation of machining forces with cutting speed

The variations of machining forces with cutting speed in shown in Fig. 5. It is

seen that after an initial rise, the cutting force component decrease in magnitude as the

cutting speed increases. With low cutting speed, the cutting wedge tends to plow on the

work surface, resulting in higher order cutting force, but as the cutting speed increases,

the cutting becomes more or less steadier, with a consequent reduction in cutting force

component.

Figire 5

From the Fig. 5, it can be seen that the cutting force component was greater than

the thrust force component by a considerable margin. These results were in agreement

Lanna, 2004 and indicate that the material removal has occurred in ductile manner

without fracture thus preventing the occurrence of a brittle material removal [24]. The

effect of variations in operating parameters may be seen in cutting forces and surface

temperatures, but knowledge of what takes place internal to the workpiece is extremely

desirable.

During machining, a considerable amount of temperature rise occurs in the cutting

zone Fig. 6 and 7.

Figire 6

Figire 7

This heat has to be normally dissipated by the work-piece, tool, chip and the

surroundings. But in gray cast iron machining, since the work-piece is a good conductor

of heat, a major portion of the heat developed at the cutting zone has to be dissipated by

the tool and chip. Therefore, the dependence of temperature on cutting speed will exert

a greater influence on the tool performance especially at higher speeds. With lower

order cutting velocity, the cutting wedge of the tool tends to plow on to the work surface

resulting in a marginally higher order force. As the cutting speed increases, the cutting

becomes steadier with a consequent reduction in cutting force components. The

decrease in cutting forces above a cutting velocity of 300 m/min can be attributed to the

possible thermal degradation of the gray cast iron. The other two components of the

machining force, namely, the thrust and feed forces also exhibited a similar trend.

3.3. Variation of machining forces with feed of cut

The effects of the variations of the feed of cut on the machining forces were

studied using the cutting velocity of 300 m/min, and with a tool having a negative rake

angle of 20◦. The variations of machining forces with the variation in feed of cut are

shown in Fig. 8.

Figire 8

All the three components of the machining force are seen to increase with the feed

of cut. The cutting force dominates over the thrust and feed force components clearly

indicating the material removal by plastic deformation.

3.4. Surface roughness

Surface finish was shown to be improved by increasing cutting speed (Fig. 9),

though the improvement was very limited.

Figire 9

Producing a better surface finish at higher cutting speed is not something unusual

in metal cutting [25]. It is observed that the surface finish is not affected by the

increased tool flank wear. In all cutting conditions, the variation of surface finish with

the flank wear is insignificant. The surface roughness values remained almost constant

although the flank wear increased with the increase of time to feed and depth of cut

constant. However, the magnitude of surface roughness is higher for lower cutting

speed. When increase cutting speed and feed rate constant (0.33 mm/rev), surface finish

even improved with the increase of flank wear (Fig. 10).

Figire 10

However in this paper observe that increasing wear of cutting tool improved the

roughness of the workpiece. These results have been common when using ceramic

cutting tools on machining gray cast iron [26].

3.5. Flank wear

Fig. 11 shows the flank wear progression with increasing cutting length for

Vc=300 m/min, feed rate of 0.33 mm/rev and depth of cut was kept constant at 1.0 mm.

Figire 11

Flank wear measurements were taken at an interval of every 1500 m length cut.

With the workpiece diameter of 105 mm and employed depth of cut of 1 mm, when the

tests were stopped when the maximum flank wear value (VBmax) exceeded 0.3 mm. In

this was represent one micrographs of cutting tools that use in machining longer time

because in others conditions flank wear exhibited low and similar wear behaviors at all

cutting speeds Fig. 12. In this Figure can be seen more clearly the average flank wear

(VBmax), in which shows the in Fig. 11 by the corresponding maximum cutting length

(in m).

Figire 12

It is clearly seen that flank wear rate curves is linear with cutting length indicating

that cutting tools have had long life was agreement [19].

4. Conclusions

The results of turning of gray cast iron using silicon nitride base tools were

presented. The effect of cutting speed and feed of cut on machining forces were

analyzed. Studies have indicated that:

1. The Si3N4 based ceramic cutting present important performance in high-speed

turning of gray cast iron. The low wear of the insert suggests that this tool is suitable for

machining gray cast iron.

2. The cutting process becomes more and more stable as the speed increases. The

accommodation during cutting at the highest speed can be better. This might suggest

that high-speed machining is more and more stable for the tool–work–machine system

under consideration, with decrease in the force components up to speed of 300 m/min.

3. As the feed of cut is increases the machining forces also increase.

4. Several it is possible observe that all the two components of the roughness are

seen to decrease with the length of cut.

5. Surface finish of the work part is not influenced by the tool wear. However,

increasing speed, feed or depth of cut does influence the surface finish.

6. The cutting force decreases with increasing cutting speed owing to the high

temperatures generated at the cutting zone. The decrease in the cutting force obtained

with Si3N4 based ceramic cutting tool is more to machining gray cast iron. This, together

with the results obtained for flank wear and surface roughness, indicates that, among

many tools Si3N4 will have the most suitable tool, for turning of gray cast irons at high

cutting speeds.

Acknowledgement

The authors would like to thank for financial support by CAPES and FAPESP.

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471.

[2] S. Van Luttervelt, T.H.C. Childs, I.S. Jawahir, F. Klocke and P.K. Venuvinod,

Present situation and future trends in modelling of machining operations, Ann CIRP 47

(1998) (2), pp. 587–626.

[3] J.V.C. Souza, E. A. Cunha, M.R.V. Moreira, G. V. Martins, E. A. Raymundo, C. A.

Kelly, Torneamento do ferro fundido vermicular utilizando pastilhas cerâmicas à base

de negrito de silício (Si3N4), Anais, Congresso de Usinagem, (2004), Brazil.

[4] K.F. Ehman, S.G. Kapoor, R.E. DeVor and I. Lazoglu, Machining process

modeling: a review, J Manufact Sci Eng Trans ASME 119 (1997), pp. 655–663.

[5] L.N. López de Lacalle, A. Lamikiz, J.A. Sánchez and I. Fernández de Bustos,

Recording of real cutting forces along the milling of complex parts, Mechatronics,

V.16, (2006), PP. 21-32.

[6] L.N. López de Lacalle, A. Gutiérrez, J.I. Llorente, J.A. Sánchez and J. Albóniga,

Using high pressure coolant in the drilling and turning of low machinability alloys, Int J

Adv Manufact Technol 16 (2000) (2), pp. 85–91.

[7] S.A. Tobias, Machine-tool vibration, Blackie, London (1965).

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technology, Chapman and Hall, London (1985) pp. 48–153.

[9] Ductile Iron Data For Desing Engineer, Ductile Iron Society (DIS), 2001.

[10] E.M. Trent, Metal Cutting, Tanner Ltd., London (1984).

[11] The Iron Casting Handbook, Iron Casting Society, Inc., 1981.

[12] Machining Data Handbook, 3rd ed., Metcut Research Associates, Inc., Cincinnati,

OH, 1980.

[13] Machining Ductile Irons, International Nickel Co. Inc., New York, 2001.

[14] T. Sornakumar, M.V. Gopalakrishnan, R. Krishnamurthy and C.V. Gokularatnam,

Development of alumina and Ce-TTZ ceramic composite (ZTA) cutting tool. Int. J.

Refract. Metals Hard Mater. 8 (1995), pp. 375–378.

[15] A. Senthil Kumar, A. Raja Durai and T. Sornakumar, Machinability of hardened

steel using alumina based ceramic cutting tools, International Journal of Refractory

Metals and Hard Materials V. 21, (2003), pp 109-117.

[16] W. Chen, Cutting forces and surface finish when machining medium hardness steel

using CBN tools. Int. J. Mach. Tools Manufact. 40 (2000), pp. 455–466.

[17] A. Chakraborty, K.K. Ray and S.B. Bhaduri, Comparative wear behavior of

ceramic and carbide tools during high speed machining of steel. Mater. Manufact.

Process. 15 (2000), pp. 269–300.

[18] A.G. Evans and E.A. Charles, J Am Ceram Soc 59 (1976), pp. 7–8.

[19] N. Camuşcu, Effect of cutting speed on the performance of Al2O3 based ceramic

tools in turning nodular cast iron, Materials & Design, V.10, (2006), pp. 997-1006.

[20]. C.W. Beeghly. In: J.A. SwartleyLoush, Editor, Tool Materials for High Speed

Machining, ASM International, USA (1987), p. 91.

[21] S.K. Bhattacharyya, E.O. Ezugwu and A. Jawaid. Wear 135 (1989), p. 147.

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of microstructural design of β-Si3N4 ceramics. Z. Metallkd 92 7 (2001), pp. 788–795.

[24] M.A. Lanna, A.A.L. Bello, J.V.C. Souza, Avaliação das tensões e deformação em

ferramentas cerâmicas de nitreto de silício, Anais 48º Congresso Brasileiro de

Cerâmicas, (2004), Brazil.

[25] South China Institute of Technology (Ed.), Principles of Metal Cutting and Design

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Process, Anais, UNINDU, (2005), Brazil.

List of captions for illustrations

Fig. 1. Photograph of silicon nitride based insert.

Fig. 2. Force components measured in turning tests [26].

Fig. 3. XRD pattern of sintered ceramic cutting tool, using Cu Kα radiation.

Fig. 4. Microstructure of cutting tools.

Fig. 5. Typical variation of machining forces with cutting speed.

Fig. 6. Temperature vs feed to vc = 300m/min.

Fig. 7. Temperature vs cutting speed to f = 0.33mm/rev.

Fig. 8. Forces vs feed to vc = 300m/min.

Fig. 9. Surface roughness vs cutting speed to. f=0.33 mm/rev, ap=1.0 mm.

Fig. 10. Surface roughness vs cutting speed to f=0.33 mm/rev, ap=1.0 mm.

Fig. 11. Flank wear vs cutting length vc = 300m/min, f=0.33 mm/rev, ap=1.0 mm.

Fig. 12. Micrograph of cutting tool after machining to cutting length of 7500m.

List of captions for table

Table 1. Chemical composition and mechanical properties of gray cast iron used for

cutting test (Hick, 2000)

Fig1

Fig2

10 20 30 40 50 60 70 800

100200

300400500

600700

αααααααα αααααααααααα ααααααααααααaaa a aaa

ααααa ββββββββββββ

ββββββββββββ

ββββ

ββββ

ββββ

ββββ

ββββ

ββββ ββββββββββββ

ββββββββ

ββββ

ββββ

ββββ

Inte

nsity

(a.u

)

2θθθθ (0)

ββββ- Si3N4

a- Y3Al5012

αααα-Si3N4

Fig3

2µm

Fig4

-60 0 60 120 180 240 300 360 420 480

0

100

200

300

400

500 Cutting force Thrust force Feed force

Forc

e (N

)

Cutting speed

Fig5

0,0 0,1 0,2 0,3 0,4 0,5-100

0

100

200

300

400

500

600

700

800

Tem

pera

ture

( o C

)

Feed f (mm/rev)

Temperature x Feed to Vc= 300m/min

Fig6

-60 0 60 120 180 240 300 360 420 480-100

0

100

200

300

400

500

600

700

800

Tem

pera

ture

( o C

)

Cutting speed (m/min)

Temperature x Cutting tools to f=0,33mm/rev

Fig7

0,0 0,1 0,2 0,3 0,4 0,5 0,6

0

100

200

300

400

500

600

700

800

Forc

e (N

)

Feed f (mm/rev)

Cutting force Thrust force Feed force

Fig8

-60 0 60 120 180 240 300 360 420 480-0,50,00,51,01,52,02,53,03,54,04,55,0

Rou

ghne

ss R

a ( µµ µµ

m)

Cutting speed Vc (m/min)

Roughness Ra x cutting tools to f=0,33mm/rev

Fig9

-60 0 60 120 180 240 300 360 420 480

0

5

10

15

20

25

30

Rou

ghne

ss R

y ( µµ µµ

m)

Cutting tools Vc (m/min)

Roughness Ry x Cutting tools to f=0,33mm/rev

Fig10

0 1500 3000 4500 6000 7500 90000,000,050,100,150,200,250,300,35

Vc = 300m/min, f=0.33 mm/rev, ap=1.0 mm

Flan

k w

ear

(mm

)

Cutting length (m)

Fig11

1mm

Fig12

Chemical composition of gray cast iron C S P Si Mn Cu Cr Ni Mo 3.04 0.11 0.068 2.58 0.42 0.05 0.07 0.02 0.005

Mechanical Properties Hardness HB 205 Tensile strength MPa 245 Fatigue strength MPa 100

Table1