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Investigation of the effect of boron carbide-doped diamond sockets on cutting performance in granite cutting

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In the study, boron carbide was added to the matrix in different ratios in order to increase the wear resistance of the socket matrix and to strengthen the bond at the matrix interface with the diamond. Under the same sintering conditions, eight different tool sockets were produced. One of them is boron carbide non-doped (0% B4C) reference socket. The others are boron carbide-doped sockets in different ratios (1-2-3-4-5-6-7% B4C). The produced sockets were welded around a 350-mm saw to produce circular saws. In the study, firstly, the metallographic properties of the boron carbide non-doped (0% B4C) and boron carbide-doped (1-2-3-4-5-6-7% B4C) sockets such as theoretical densities, unit volume weights, porosity, Knoop hardness (HK), and weight wear loss were determined. Cutting experiments were then carried out (under constant cutting conditions) with eight different circular saws on a single hard stone species with a homogeneous structure. At the end of cutting experiments, the power consumption, specific cutting energy, specific abrasion, and noise levels of each saw were determined. Cutting performance of boron carbide non-doped and doped circular saws has been investigated taking into account the metallographic properties of the sockets. At the end of the study, the lowest power consumption and specific cutting energy consumption due to high porosity and low hardness were obtained at 7% B4C-doped sockets. It was determined that the lowest specific abrasion value was found in sockets with 4% B4C doped due to the low porosity and high hardness value, and the lowest noise level was found in 1% B4C-doped sockets.
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ORIGINAL PAPER
Investigation of the effect of boron carbide-doped diamond sockets
on cutting performance in granite cutting
Gökhan Ekincioğlu
1
&Raşit Altındağ
2
Received: 2 November 2018 / Accepted: 6 February 2019
#Saudi Society for Geosciences 2019
Abstract
In the study, boron carbide was added to the matrix in different ratios in order to increase the wear resistance of the socket matrix
and to strengthen the bond at the matrix interface with the diamond. Under the same sintering conditions, eight different tool
sockets were produced. One of them is boron carbide non-doped (0% B
4
C) reference socket. Theothers are boron carbide-doped
sockets in different ratios (1-2-3-4-5-6-7% B
4
C). The produced sockets were welded around a 350-mm saw to produce circular
saws. In the study, firstly, the metallographic properties of the boron carbide non-doped (0% B
4
C) and boron carbide-doped (1-2-
3-4-5-6-7% B
4
C) sockets such as theoretical densities, unit volume weights, porosity, Knoop hardness (HK), and weight wear
loss were determined. Cutting experiments were then carried out (under constant cutting conditions) with eight different circular
saws on a single hard stone species with a homogeneous structure. At the end of cutting experiments, the power consumption,
specific cutting energy, specific abrasion, and noise levels of each saw were determined. Cutting performance of boron carbide
non-doped and doped circular saws has beeninvestigated taking into account the metallographic propertiesof the sockets. At the
end of the study, the lowest power consumption and specific cutting energy consumption due to high porosity and low hardness
were obtained at 7% B
4
C-doped sockets. It was determined that the lowest specific abrasion value was found in sockets with4%
B
4
C doped due to the low porosity and high hardness value, and the lowest noise level was found in 1% B
4
C-doped sockets.
Keywords Diamond sockets .Boron carbide .Granite .Specific cutting energy .Specific abrasion .Noise
Introduction
Natural stone blocks produced from quarries come to marble
processing plants where they are presented to the market as
semi-finished or finished products. Circular saws are used for
sizing of natural stones in the factory. The cost of cutting
among the cost items constitutes a significant share. The most
important factor in cutting cost is energy and saw cost. The
energy consumption value in the cutting process varies de-
pending on the rock and machine parameters. Physical and
mechanical properties of the rock and hard mineral affect the
cutting process. In addition, parameters such as cutting speed,
cut depth of saw, structure of socket, and the power of the
machine affect the specific cutting energy, specific abrasion,
and noise. One of the biggest problems encountered in the
operation of natural stones is that they shorten the life of the
cutters usedin natural stone cutting and cause the natural stone
production costs to increase to a great extent. Determination of
cutters suitable for the rocks has an important role in decreas-
ing natural stone processing costs.
The cost of natural stone production is controlled by the
largely cutter productivity, which is affected considerably by
the cutting wear conditions (Ersoy and Atıcı1999). Many stud-
ies have been done in the literature on optimization of natural
stone cutting, energy estimation, socket wear, and socket con-
struction. Some of these studies are summarized below.
Studies on specific cutting energy and cutting forces
Büyüksağiş(1998) conducted cutting tests on seven marbles
and determined cutting forces and specific energy values
according to the data obtained from these cutting experiments.
Editorial handling: Murat Karakus
*Gökhan Ekincioğlu
gekincioglu@ahievran.edu.tr
Raşit Altındağ
rasit@mmf.sdu.edu.tr
1
Kaman Vocational School Department of Drilling Technology, Ahi
Evran University, 40100 Kirşehir, Turkey
2
Faculty of Engineering Department of Mining Engineering,
Süleyman Demirel University, Isparta, Turkey
Arabian Journal of Geosciences (2019) 12:170
https://doi.org/10.1007/s12517-019-4329-9
Using multiple regression technique, empirical approaches
have been developed to determine the required cutting force
andspecificenergyvaluesbyrockproperties.Xu(1999)con-
ducted cutting experiments with five different granites in a cir-
cular sawing machine. In these experiments, shear forces and
specific shear energy values are calculated. In addition, it was
determined that the surfaces of the granite samples were exam-
ined under the microscope and the energy consumed in the
cutting was increased due to the increase of the rock friction
coefficient. Karakuş(1999) performed performance measure-
ments on four different rocks on block cutting machines in the
marble factory and examined the cutability parameters of mar-
bles. In the study, the relationship between the physico-
mechanical properties of the rocks and the cutting energy was
investigated. BüyüksağişandGoktan(2005) considered specif-
ic energy as a criterion for cutting efficiency and conducted
cutting tests to determine optimum cutting conditions for
seven different marbles. In the study, specific cutting ener-
gy was correlated with Cerchar abrasion index, Mohs hard-
ness, and uniaxial compressive strength by multiple regres-
sion analysis. Atıcı(2005) performed cutting experiments
on 10 different rocks at different cutting depths, different
cutting speeds, and different peripheral speeds. The rela-
tionship between the rock properties and the specific cut-
ting energy and the wear rates of the saws are investigated.
Büyüksağiş(2007) conducted cutting experiments on six
granite samples with circular saws up and down. The spe-
cific energy and specific abrasion values in the sockets are
calculated in the cutting experiments. Empirical ap-
proaches between specific energy and specific abrasion
values are revealed using multiple regression analyses.
GüneşYılmaz and Göktan (2008) performed cutting exper-
iments on two different granite samples. In this study, the
effects of cutting depth and cutting speed on cutting forces,
power consumption, and specific energy are investigated.
Şengün et al. (2009) conducted cutting experiments using
four different magmatic rock types. They calculated the
specific cutting energy for each rock type from the data
obtained in the constant cutting parameters. They per-
formed regression analyses to determine the effect of the
physical and mechanical properties of rocks on cutting en-
ergy. In the cutting process, the porosity and compressive
strength of the rocks play an important role. Yurdakul and
Akdaş(2012) calculated the specific shear energy values in
order to determine the cutability of six different carbonate
sources in seven different block cutting machines in three
different natural stone processing plants. The relationships
between the physico-mechanical properties of the rocks
and the specific cutting energy values are investigated by
statistical analysis.
Researches on socket wear
Xu et al. (2002) evaluated horizontal and vertical forces on
diamond grains by performing cutting tests on two different
types of granites. The temperature formed in the diamond-
granite cutting zone was measured by thermocouple. They
have determined that this measured temperature value is im-
portant for diamond wear. Eyuboglu et al. (2003)determined
the physico-mechanical properties of 24 andesite blocks ex-
tracted from the same marble quarry. After the block cutting
operations in the factory, they determined the wear rates in the
saw. They investigate the relationship between the specified
abrasion rates and the physico-mechanical properties of the
rock. Polini and Turchetta (2005) performed cutting experi-
ments on two different granite samples with two different
Table 1 Boron carbide chemical content
Element B C O Fe Si
%7577 1821 0.1* 0.150.25* 0.1*
*Maximum value
%0 %1 %2 %3 %4 %5 %6 %7
Fig. 1 Appearance of circular
saws with boron carbide additive
and additive diamond inserts
Table 2 Theoretical density (TD) and unit volume weight (UVW)
values of boron carbide-doped diamond sockets
%B
4
CTD(g/cm
3
) UVW (g/cm
3
) Number of
experiments
0 8.34 8.05 3
1 8.15 7.56 3
2 7.97 7.53 3
3 7.80 7.34 3
4 7.62 7.30 3
5 7.47 6.82 3
6 7.29 6.42 3
7 7.06 6.05 3
170 Page 2 of 13 Arab J Geosci (2019) 12:170
saws. After the cutting tests, they have determined the
abrasions in the saws with both diametrically and with
weight reductions. The relationship between saw wear
values and the volume of material produced during
cutting is shown. Özçelik et al. (2008) have performed
cutting experiments with sockets produced at different
diamond concentrations. They determined that the unit
wear decreased with the cutting depth and the increase
in diamond concentrations.
Researches on noise
Şengün et al. (2010) determined the noise levels in various
marble processing plants and compared them with the limit
values. At the end of the study, they determined that the noise
level in the marble processing plants is higher than the limit
values for continuous operation. Şengün et al. (2013) per-
formed cutting experiments on 10 different rocks. In the cut-
ting experiments, they measured the noise values and the saw
cycle during cutting of the saw. The relationships between the
physical and mechanical properties of the rocks and the
saw cycle and noise values are statistically investigated.
They emphasized that work safety and worker health pre-
cautions should be increasedinthecuttingprocessesof
hard and high strength rocks. GüneşYılmaz (2013)has
carried out cutting experiments with two different saws,
the sandwich-core saw, and the conventional saw, on the
Blue Pearl granite sample.
In the cutting experiments, the effects of the saws on the
specific wear rate and noise emission were investigated. As a
result of the cutting experiments, it was determined that the
sandwich-core saw had a lower specific wear rate and the
average sound level was about 10 dB lower than the conven-
tional saw.
Studies on socket matrix
Luo and Liao (1995) investigated the effect of diamond
type and grain size on cutting performance. They per-
formed cutting tests on granite samples with fine-grained
and coarse-grained diamond saw blades with the same con-
centration. It has been determined that fine-grained dia-
mond sockets perform better than coarse-grained diamond
sockets for hard rocks.
However, they have shown that fine-grained diamond
sockets have higher cutting force values than coarse diamond
sockets. Li et al. (2002) emphasized low wear, low energy
consumption, and high shear efficiency for low-cost cutting
in granite cutting in circular saws.
They pointed out that the amount of wear in the sockets
is related to machine parameters, diamond tool surface, and
rock properties. Experimental studies have been carried out
on granite specimens with sockets made of Ti-Cr-coated
diamond grains. Xu and Yu (2005) used Ti-Cr-coated and
uncoated diamond beads in three different matrix struc-
tures and performed cutting tests on a single granite sam-
ple. After cutting tests, they determined that wear values of
Ti-Cr-coated sockets decreased.
Studies using boron doped in socket matrix
Hwang et al. (2005) have used boron-doped nickel alumi-
num instead of cobalt in socket matrix. At the end of the
Fig. 3 Appearance from unit volume weight experiments
Table 3 Porosity values
%B
4
C Porosity (%) Number of
experiments
03.48 3
17.24 3
25.52 3
35.90 3
44.20 3
58.70 3
6 11.93 3
714.31 3
4
5
6
7
8
9
5
5.5
6
6.5
7
7.5
8
8.5
01234567
UVW (gr/cm3)
B4C (%)
TD (gr/cm3)
Fig. 2 Effect of boron carbide additive on unit volume weight and
theoretical density
Arab J Geosci (2019) 12:170 Page 3 of 13 170
study, it was determined that the hardness and tensile
strength of boron-doped sockets increased. However, cut-
ting performance of boron-doped sockets has not been de-
termined in the study. Özel et al. (2009) produced Cu-Al-
B
4
C metal matrix composites under the same sintering
conditions by adding 5%, 10%, and 20% B
4
C into Cu-
5% Al powder mixture. They have examined the micro-
structures of the pressed samples. The hardness values
were also measured and the highest hardness values were
determined in the sample with 20% B
4
C addition. Öksüz
et al. (2011) produced two types of marble sockets with the
same cobalt and iron ratios, keeping diamond concentra-
tions and bronze ratios constant. They added 0.7% B
4
Cto
these two types of socket matrix and investigated the effect
of B
4
C addition on socket hardness and abrasion
resistance. Brinell hardness values were measured at five
different points of each composite material under 100 kgf
force and mean hardness values were determined. It was
shown that the matrix hardness decreased with Fe addition,
but matrix hardness increased with B
4
C addition. Islak
et al. (2012) examined the effect of boron carbide additives
on the microstructure and mechanical properties of dia-
mond sockets. They produced four different sockets with
0%, 2%, 5%, and 10% boron carbide added. The sockets
were manufactured at 700 °C, under 35 MPa pressure and
3 min of sintering. As the ratio of boron carbide increased,
hardness increased but bending strength decreased.
When the scientific studies on the cutability of rocks are
examined in literature, it is seen that the relations between
mineralogical, physical, and mechanical properties of rocks
are taken into consideration by cutting parameters such as
saw diameter, saw cycle, cutting depth, feed rate, cutting
forces, specific cutting energy, and specific wear.
In the studies on the development of socket matrix,
the parameters of socket production such as sintering
time, temperature, and pressure have been changed.
Furthermore, the addition of different metals (Co, Mb, Ti) to
the matrix structure, the effects of diamond ratios, and sizes
have also been investigated by many researchers. However,
these studies have been limited to metallographic investiga-
tions and the cutting performance of the diamond socket saws
has not been determined.
0
2
4
6
8
10
12
14
16
01234567
3.48
7.24
5.52 5.9
4.2
8.7
11.93
14.31
% Porosity
%B
4
C
% 0 reference line
Fig. 4 Porosity change according
to boron carbide doped
Fig. 5 View from Knoop hardness experiments
Table 4 Knoop hardness
(HK) values %B
4
CHK
0244.47
1241.58
2253.35
3279.13
4303.46
5244.67
6234
7242
170 Page 4 of 13 Arab J Geosci (2019) 12:170
In this study, besides determining the metallographic
properties of boron carbide-doped sockets different from
the literature, cutting tests were performed under the same
conditions and cutting performance was determined.
Boron carbide
Boron carbide is an important boron end product with a
high market volume among hundreds of boron chemistries
worldwide (Alp et al. 2013). Boron carbide is used in the
processing of ceramics and hardworking materials such as
saws, as well as finding space in various fields depending
on their physical properties (Karaçay 2008).
To increase the wear resistance of the metallic matrix
and to strengthen the bond at the matrix interface with
the diamond, carbides are added to the matrix. Recently,
boron carbide, which has high melting point, high hard-
ness, low density, high chemical stability, and excellent
mechanical properties, is an important material for ad-
vanced technology. Boron carbide is the hardest material
known after diamond and cubic boron nitride. Due to its
high hardness, abrasion is used to improve the resistance
(Pierson 1996;Maetal.2010; Islak et al. 2012).
In the natural stone sector, the shortage of sockets used
especially for the cutting of hard natural stones of granite
type and the increase of the production cost per square
meter as a result of this constitutes a serious problem. In
the scope of the study, boron carbide was also supplied
and used in the socket matrix in order to increase the
resistance against wear of the diamond socket. In
Table 1, the chemical content of boron carbide used in
diamond sockets is given.
Experimental studies
In the scope of the study, firstly, a reference saw is
produced with 0% (B
4
C) without an additive boron car-
bide. Subsequently, boron carbide-added sockets were
produced in seven different percentages (1-2-3-4-5-6-7
B
4
C). The obtained diamond sockets were welded
around a circular plate with a diameter of 350 mm and
circular saws suitable for granite cuts were produced.
The sockets were manufactured at a temperature of
73Candasinteringdurationof3minunderapres-
sure of 35 MPa. The appearance of circular saws with
boron carbide-added diamond inserts is given in Fig. 1
(Ekincioğlu 2017).
200
220
240
260
280
300
320
01234567
244.47 241.58
253.35
279.13
303.46
244.67
234
242
HK
B4C (%)
% 0 reference line
Fig. 6 Knoop hardness (HK)
value change according to boron
carbide doped
Fig. 8 Measurement before and after wearFig. 7 Wear test set
Arab J Geosci (2019) 12:170 Page 5 of 13 170
Within the scope of experimental studies, theoretical den-
sities, unit volume weights, porosities, Knoop hardnesses
(HK), and weight loss values were determined in order to
determine the metallographic properties of boron carbide-
doped diamond sockets. Later, cutting tests were carried out
on a single granite type with constant cutting parameters such
as cutting depth, feed rate, saw peripheral speed, and the
amount of water. As a result of cutting tests, net power con-
sumption, specific cutting energy, specific wear, and noise
values of circular saws were determined. According to the
results obtained, cutting performance of boron carbide-
doped sockets was determined.
Metallographic properties of boron carbide-doped
diamond sockets
Theoretical density and unit volume weight
The unit volume weight values of boron carbide-doped dia-
mond sockets are determined according to ASTM B 311-08
standard (ASTM 2009). The theoretical densities of boron
carbide-doped diamond sockets are calculated according to
the boron carbide, cobalt, nickel, bronze, and diamond ratios
in the matrix. The unit volume weights (UVW) and the
theoretical densities (TD) of the boron carbide-doped dia-
mond sockets are given in Table 2.
It was determined that the unit volume weight decreased
with the increase of the amount of boron carbide. This is due
to the low boron carbide density (2.52 g/cm
3
)comparedto
cobalt (8.90 g/cm
3
), nickel (8.85 g/cm
3
), and bronze (8.60 g/
cm
3
) used in the matrix (Rahimian et al. 2009; Islak et al.
2012). Another reason is that the boron carbide melting point
is higher than the other matrix materials and therefore affects
the sintering process negatively (Islak et al. 2012). Figure 2
shows the effect of the boron carbide addition on the unit
volume weight and the theoretical density.
Porosity
Porosity affects the mechanical properties of a material as well
as corrosion and mechanical wear behavior due to the mate-
rials contained in the matrix (Fig. 3). In the study, porosity
values of boron carbide-doped sockets were determined ac-
cording to Eq. 1.
P¼100UVW=TD*100ðÞ ð1Þ
Pporosity
UVW unit volume weight
TD theoretical density
Calculated porosity values are given in Table 3. It was
observed that the boron carbide doped increased porosity.
The porosity ratio is increased because the bond between
the boron carbide and theother matrix material interface is not
stable due to the difference between the melting points.
Figure 4shows porosity change with respect to boron carbide
contribution.
Hardness
During the rock cutting process, the matrix is exposed to fa-
tigue because of variable loads. The most important task of the
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
01234567
0.00374
0.005
0.00445 0.0045
0.00297
0.00643 0.00628
0.00768
Weight Wear Loss (gr)
B4C (%)
% 0 reference line
Fig. 9 Change in weight wear
loss according to boron carbide
doped
Table 5 Wei gh t wear
loss test results %B
4
CWeightwear
loss (g)
0 0.00374
1 0.00500
2 0.00445
3 0.00450
4 0.00297
5 0.00643
6 0.00628
7 0.00768
170 Page 6 of 13 Arab J Geosci (2019) 12:170
matrix is to keep the diamond particles inside tightly. For this
reason, the rigidity of the matrix has great precaution. Matrix
hardness is largely dependent on the chemical composition of
the used powder and its production parameters and in practice,
hardness is regarded as a fundamental quality control param-
eter for sockets (Kır2012).
In this study, Knoop hardness (HK) values were measured
in the micro hardness measuring device of MITECH brand in
Aha Evran University Kaman Vocational SchoolsRock
Mechanics Laboratory in order to determine hardnesses of
boron carbide-doped diamond sockets obtained by hot press-
ing (Fig. 5).
In the hardness measurements, three specimens of dimen-
sions 3.2 × 10 × 40 mm were used for each boron carbide
ratio. Measurements were made 50 times at frequent intervals
from the surface of each sample and the whole socket surface
was scanned. A total of 1200 hardness measurements were
made and the averages were taken (see Table 4).
The highest hardness value was obtained in 4% boron
carbide-doped sockets and the lowest hardness value was ob-
tained in 6% boron carbide-doped sockets depending on po-
rosity values. Figure 6shows the change of Knoop hardness
value according to boron carbide doped.
Weight wear loss
The purpose of using reinforcing elements in composite ma-
terials is to create hard phases within the soft structure. The
hard phases increase both wear resistance and toughness
(Özay and Hasçalık2004). In the scope of the study, boron
carbide-doped diamond sockets were produced at different
rates by using hot pressing method in order to increase wear
resistance of diamond sockets.
Weight abrasion tests were carried out by using the
wear test set in the laboratory of Metallurgical and
Materials Engineering Department of Fırat University
(Fig. 7). In the wear tests, two samples were used from
each group of diamond sockets. In the abrasion tests,
the specimen was fixed primarily and then traveled
13 m with a load of 2 kg/cm
2
on diamond pin rotating
at 30 rpm.
Surfaces were cleaned with alcohol before and after
the surface abrasion test of the samples (Fig. 8). Dry
weights of the samples were taken prior to the abrasion
tests. As a result of the wear tests, the samples were
reweighed to determine wear losses. Sensitive scales are
used in the experiments. The obtained data are given in
Table 5.Figure9shows the change in weight wear loss
with respect to the boron carbide doped.
2
1
3
4
6
7
8
9
5
1. Saw 6. Wear measurement system
2. Saw engine 7. Energy analyser
3. Coolant pump 8. Electric panel
4. Carriage 9. Noise meter
5. Sample
Fig. 10 General appearance of
cutting test set elements
Table 6 Cutting parameters held constant in cutting experiments
Peripheral speed
(Vç), m/sn
Cutting depth
(hk), mm
Feed rates
(Vi), m/dk
30 10 0.7
Table 7 Physical and mechanical properties of Hisar Gray rock
Min Avg Max
SW 2.689 2.697 2.701
UVW (g/cm
3
) 2.613 2.622 2.632
TP (%) 2.380 2.784 3.030
BSW (cm
3
/50 cm
2
) 7.601 7.640 7.677
UCS (MPa) 174.78 206.63 237.07
Is
(50)
(MPa) 7.10 7.97 9.36
BTS (MPa) 8.13 9.85 10.54
HK 315.65 445.82 622.12
SH 79.5 90.8 98.2
SW, specific weight; UVW, unit volume weight; TP, total porosity; UCS,
uniaxial compressive strength; Is
(50)
, point load strength index; BTS,
Brazilian tensile strength; SH, Shore hardness; HK, Knoop hardness
Arab J Geosci (2019) 12:170 Page 7 of 13 170
When the results obtained are examined, it is deter-
mined that 4% boron carbide-doped diamond sockets have
the least mass loss due to high hardness. The highest
weight wear loss value was obtained in 7% boron
carbide-doped sockets due to low hardness and high po-
rosity value. Figure 6shows the weight wear loss change
with respect to the boron carbide doped.
Cutting experiments
As a result of cutting experiments with boron carbide-
doped and non-doped circular saws, net power consump-
tion, and specific cutting energy that each saw consumed
during cutting, noise values generated during cutting and
specific wear values formed in sockets after cutting were
determined.
Cutting experiments were carried out in cutting set in the
Natural Stone Technology Laboratory of Mining Engineering
Department of leyman Demirel University. Figure 10 gives
an overview of the cutting test set elements.
Cutting performances of eight circular saws with boron
carbide-free and doped (0-1-2-3-4-5-6-7 B4C) were deter-
mined in the study. Cutting parameters such as the peripheral
speed of the saw, feed rates, cutting depth, and water volume
were kept constant during cutting experiments. Cutting pa-
rameters are given in Table 6.
A single natural stone type was used in the cutting exper-
iments. Cutting experiments were carried out on Hisar Gray
samples of 5 × 10 × 25 cm dimensions with a homogeneous
structure. Physical and mechanical properties of Hisar Gray
samples were determined before cutting experiments. The re-
sults are given in Table 7.
In the experiments, the downward cutting method widely
used in the natural stone sector was chosen. Before the cutting
experiments, abrasive concrete blocks were used to sharpen
the saws. In the experiments, a constant amount of cooling
water (10 l/min) was used with an external pump. In cutting
experiments, 12 cuts were made on each block sample. For
each saw, 60 cuts were made on 5 block samples. The appear-
ance of block samples of dimensions 5 × 10 × 25 cm after the
cutting experiments is given in Fig. 11.
Specific cutting energy
The specific cutting energy is defined as the amount of energy
required to cut the rock in the unit volume and expressed in
units of J/mm
3
. The efficiency of the cutting depends on the
maximum cutting speed and the minimum specific cutting
energy. Providing these conditions is the most economical of
the cutting process. For this reason, specific cutting energy is a
criterion of cutting efficiency (Şengün 2009).
Fig. 11 View of block samples
after cutting test
Fig. 12 Power-cutting time graph of 0% B
4
Csaw
Table 8 Specific cutting energy values
%B
4
C SCE (J/mm
3
)
Min Avg Max Deviation Cutting
number
0 1.3469 1.4553 1.5153 0.051 60
1 0.8883 1.0493 1.2197 0.095 60
2 0.9895 1.0986 1.2575 0.081 60
3 1.0586 1.2632 1.4495 0.069 60
4 1.3945 1.4826 1.5498 0.076 60
5 1.0715 1.1896 1.2862 0.078 60
6 0.7449 0.9144 1.0477 0.075 60
7 0.7258 0.9044 1.0313 0.061 60
170 Page 8 of 13 Arab J Geosci (2019) 12:170
In industrial applications, attention is paid to increasing the
amount of production in the unit at a time, but the energy
consumption for this process is ignored. However, the fact
that the cutting process is economically feasible depends on
providing the most production and less energy consumption
per unit time (Büyüksağiş1998).
In the study, first power consumption values were obtained
to calculate the specific cutting energy values. Later, a power-
time graph was drawn (Fig. 12). Using the graph, the power
values the machine consumes during the unloaded operation
and the power values that are consumed during full load are
determined. The difference between these two values gives
the net power value for the rock cutting (Eq. 2).
P¼PcPb ð2Þ
P net power used for cutting, watts
Pc power consumption in case of sawing, watt
Pb power value of saw in non-load case, watt
The specificcutting energy values ofthe circular saws used
in cutting tests are calculated using Eqs. 34. Power and spe-
cific cutting energy values during cutting were determined
according to Şengün et al. (2009)study.
FT ¼P=Vp ð3Þ
SCE ¼0:06*FT=VpðÞ=h*Ws*ViðÞ ð4Þ
SCE specific cutting energy, J/mm
3
FT tangential force, N
Vp peripheral speed, m/s
hcutting depth, mm
Ws socket width, m
Vi feed rate, m/min
Parameters related to the rock properties cannot be
changed in terms of cutting efficiency but it is possible
to change parameters related to the cutting machine. In
this study, the effect of boron carbide-doped circular saw
on the specific cutting energy was investigated in fixed
cutting parameters determined on a single granite type.
The specific cutting energy values calculated after cut-
ting tests are given in Table 8.
According to the obtained data, the highest specific
cutting energy values were obtained in circular saw
blades with 0% and 4% boron carbide-doped values.
However, the 4% boron carbide-doped circular saw con-
sumed 1.95% more energy than the 0% B
4
C. As it is
observed from the metallographic investigations, it was
determined that porosity values of these two types of
socket are close to each other and hardness value of
4% boron carbide-doped socket is higher than 0%. The
lowest specific cutting energy value was obtained in a
7% boron carbide-doped circular saw. This is due to
the fact that both the hardness and the porosity values
of the saw are lower among the other circular saws.
Therefore, it has a softer structure. Figure 13 shows the
variation of specific cutting energy values according to
the boron carbide additive ratio.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
01234567
1.4553
1.0493 1.0986
1.2632
1.4826
1.1896
0.9144 0.9044
SCE (J/mm3)
B4C (%)
% 0 reference line
Fig. 13 Change of specific
cutting energy values according
to boron carbide additive ratio
Table 9 Power consumption values
%B
4
CP(watt)
Min Avg Max Deviation Cutting
number
0 642.72 707.85 760.93 28.87 60
1 429.70 529.32 618.96 57.14 60
2 511.72 561.86 677.82 50.09 60
3 481.62 570.81 651.79 53.60 60
4 675.24 720.85 785.93 48.25 60
5 575.64 636.28 713.81 37.05 60
6 386.38 452.22 522.77 36.55 60
7 368.72 430.26 480.07 33.52 60
Arab J Geosci (2019) 12:170 Page 9 of 13 170
Power consumption
In the natural stone sector, energy consumption constitutes an
important cost item, especially in circular saw and granite
production facilities. For this reason, determination of the
power values used in cutting analyses is an important param-
eter in terms of cost and cutting efficiency. The power con-
sumption values obtained as a result of the cutting tests are
given in Table 9.
As a result, the highest consumption value was obtained in
4% and 0% B
4
C saw. The lowest power consumption value
was obtained in a circular saw with 7% boron carbide doped
due to low hardness and high porosity value. It has been de-
termined that a reduction of 39.22% in power consumption
compared to 0% B
4
C saws. The power consumption change
values of the saws according to the boron carbide doped are
given in Fig. 14.
Specific abrasion
Sockets used for natural stone cutting processes especially for
the cutting of hard natural stones of granite type are abraded
quickly and are consumed in a short time. Accordingly, an
increase in production cost per square meter is an important
problem. In natural stone cutting operations, the diamond and
matrix must be worn optimally for the life of the cutting tool.
For this reason, besides the type of diamond used in sockets,
the choice of matrix is important.
In the scope of this study, a wear measurement system was
established in order to determine diametrically abrasion in
diamond sockets. MITUTOYO brand vertical linear measur-
ing instrument which can measure 25 mm with1 μmaccuracy
and MITUTOYO brand digital signal converter which makes
numerical data from vertical linear measuring instrument and
SENSORPAK software which transfers the measurements
made to the computer are available in the created system.
With this software, wear measurements have been performed
over a period of 2 ms.
Before the cutting tests, the abrasion measuring instrument
is placed at the point determined on the wagon in the cutting
test set. Measurement is carried out by placing the linear mea-
suring instrument on the reference line (see Fig. 15).
The same procedures were repeated after the cutting tests.
The amount of decrease in diamond socket height was deter-
mined by taking the difference between the first and last mea-
surements. Specific abrasion values (μc/m
2
) were determined
by the ratio of worn height difference to cutting area. The
specific abrasion values obtained are given in Table 10.
The highest hardness value is obtained depending on the
suitably condensed matrix-diamond mixture and matrix com-
position. On the other hand, if the structure of the socket is
damaged in any direction or if the condensation cannot be
completed, sufficient hardness value cannot be obtained. As
0
100
200
300
400
500
600
700
800
01234567
707.85
529.32 561.86 570.81
720.85
636.28
452.22 430.26
P (watt)
B4C (%)
% 0 reference line
Fig. 14 Change of power
consumption according to boron
carbide additive ratio
Reference Line
Fig. 15 Wear measurement
system and reference point on the
saw
170 Page 10 of 13 Arab J Geosci (2019) 12:170
a result, matrix abrasion resistance is low and matrix diamond
holding ability is poor (Çelik 2009). In the study, the highest
hardness value of 4% B
4
C was also obtained. The abrasion of
the matrix surface is reduced due to the increase in hardness.
Due to its high hardness, the lowest specific abrasion value
was achieved at a 4% B
4
C doped. In addition, 4% B
4
C-doped
diamond sockets are worn down by 6.08% less than 0% B
4
C
diamond sockets and saw life is increased. The highest wear
value was obtained in the ratio of 7% B
4
C doped, which is the
highest porosity. The change in specific abrasion values ac-
cording to the boron carbide additive ratio is given in Fig. 16.
Noise level
Today, one of the most common occupational diseases is hear-
ing loss caused by excessive noise. For this reason, marble
processing plants are making efforts to reduce the noise level,
especially when continuous disk type cutters are used. Legal
practice obliges workers to work on low-noise machines and
use noise reduction tools.
As a result of the forces applied by the saw to the stone, the
shock waves generated by the vibrations between the saw and
the rock are transmitted as noise in the air. The resulting noise
depends on saw design (steel properties, blade thickness, saw
blade diameter, socket geometry and number, width between
water channels), rock properties (hardness, mineralogical
properties, etc.), and operating parameters (cutting speed, feed
rate, cutting depth, peripheral speed, and amount of cooling
water) (Yılmaz 2009).
In this study, noise values of boron carbide-doped circular
saws during cutting were determined. During the measure-
ments, the distance between the cutting test set and the noise
meter was fixed at 2 m. The noise levels are measured in the
dB (c) band, which is sensitive to machine noise. The obtained
data are given in Table 11.
The highest noise values were found to be close to each
other with 0% B
4
C and 4% B
4
C-doped diamond sockets. The
porosity values of the sockets were increased due to the in-
crease in boron carbide-doped rate. The socket hardness de-
creased with the increase of porosity values. Accordingly, the
socket wear values increased. Due to the increase in wear
values, new diamond grains have reached the surface of the
socket and facilitated the cutting process. In this case, the
noise values decreased. The lowest value was obtained in
1% B
4
C-doped sockets and it was determined that noise re-
duction by 4.30% compared to 0% B
4
Csockets.Figure17
shows the change of noise values according to the ratio of
boron carbide doped.
50
60
70
80
90
100
110
120
130
01234567
90.34
100.15 98.98
93.73
84.84
109.7
115.41
128.52
Specific Abrasion (µ c/m2)
B4C (%)
% 0 reference line
Fig. 16 Change of specific
abrasion values according to
boron carbide doped
Table 10 Specific abrasion
values %B
4
C Specific abrasion
values (μc/m
2
)
090.34
1100.15
298.98
393.73
484.84
5109.70
6 115.41
7128.52
Table 11 Noise values
%B
4
C Noise values (dB(c))
Min Avg Max Deviation Cutting
number
0 96.33 96.98 97.79 0.31 60
1 91.53 92.81 93.66 0.71 60
2 92.17 93.02 93.74 0.21 60
3 92.85 93.96 94.70 0.41 60
4 95.75 96.25 96.99 0.34 60
5 95.28 95.65 95.96 0.29 60
6 94.32 94.98 96.51 0.53 60
7 93.05 93.69 95.55 0.50 60
Arab J Geosci (2019) 12:170 Page 11 of 13 170
Results and discussion
In this study, it is aimed to increase resistance against wear of
diamond socket by boron carbide doped for matrix composi-
tion of diamond sockets used for natural stone cutting.
Besides, cutting parameters such as power consumption, spe-
cific cutting energy, and noise values of boron carbide-doped
circular saws are determined and cutting performances of cir-
cular saws with boron carbide doped have been demonstrated.
The results obtained fromthe study are summarized below.
&As a result of increasing the amount of boron carbide, it is
determined that the weight of unit volume decreases. This
is due to the low boron carbide density (2.52 g/cm
3
)com-
pared to the cobalt (8.90 g/cm
3
), nickel (8.85 g/cm
3
), and
bronze (8.60 g/cm
3
) used in the matrix (Rahimian et al.
2009; Islak et al. 2012).
&Boron carbide doped has been observed to increase poros-
ity. The reason for this is thought to be due to the fact that
bonding at the interface of boron carbide and other matrix
materials is not robust due to the difference between the
melting points.
&As a result of wear tests, it has been determined that 4%
boron carbide-doped diamond sockets have the highest
resistance against wear due to their high hardness value.
&According tothe obtained data, the highest specific cutting
energy values were obtained in circular saw blades with
0% and 4% boron carbide-doped values. However, the 4%
boron carbide-doped circular saw consumed 1.95% more
energy than the 0% B
4
C. As it is observed from the me-
tallographic investigations, it was determined that porosity
values of these two types of socket are close to each other
and hardness value of 4% boron carbide-doped socket is
higher than 0%. The lowest specific cutting energy value
was obtained in a 7% boron carbide-doped saw. This is
due to the fact that both the hardness and the porosity
values of the saw are lower among the other saws.
&After cutting tests, specific abrasion values were deter-
mined in μm/m
2
. The lowest specific abrasion value was
obtained at a ratio of 4% B
4
C doped since the fracture
of the matrix surface decreased with increasing hard-
ness. Four percent B
4
C sockets are less than 6.0% less
than 0% B
4
C sockets and saw life is increased. The
highest abrasion value was obtained in 7% boron
carbide-doped ratio.
&Considering the lowest noise level, 1% B
4
C-doped circu-
lar sawing is considered to be beneficial to the natural
stone sector when it is taken into account in terms of
worker health and safety.
In this study, it was determined that boron carbide can be
used for cutting tool matrix. In future works, performances of
0.5-1.5-2.5% boron carbide-doped saw blades produced un-
der appropriate sintering conditions should be determined at
different cutting conditions (different cutting speeds, at differ-
ent peripheral speeds). It isalso thought that it is more accurate
to determine the optimum boron carbide ratio considering the
production costs of boron carbide-doped sockets.
Acknowledgments The authors would like to thank Süleyman Demirel
University Scientific Research Office for their support with the project
number 3100-D2-12. The authors are deeply grateful for this financial
support. In addition, the authors would liketo thank Nergis Nek Diamond
Trading Company for their support in the production of boron carbide-
doped circular saws.
References
Alp E, Karaçay E, Cabbar HC (2013) Low temperature production of
boron carbide and its characterization, vol 28. Gazi Uni. Faculty of
Engineering and Architecture Magazine, pp 293302
ASTM Standard B 311-08 (2009) Standard test method for density of
powder metallurgy (Pm) materials containing less than two percent
porosity. ASTM International, West Conshohocken
AtıcıÜ (2005) The factors effected of rock cutability. Ph.D. thesis,
Çukurova Uni., Adana, 180p
BüyüksağişIS (1998) Analysis of sawability of marbles with diamond
disc block cutter machines. Ph.D. thesis, Osmangazi Uni. Eskişehir,
172p
90
91
92
93
94
95
96
97
01234567
96.98
92.81 93.02
93.96
96.25
95.65
94.98
93.69
Noise Values (dB)
B4C (%)
% 0 reference line
Fig. 17 Change of noise values
according to boron carbide-doped
ratio
170 Page 12 of 13 Arab J Geosci (2019) 12:170
BüyüksağişIS (2007) Effect of cutting mode on the sawability of granites
using segmented circular diamond sawblade. J Mater Process
Technol 183:399406
BüyüksağişIS, Goktan RM (2005) Investigation of marble machining
performance using an instrumented block-cutter. J Mater Process
Technol 169:258262
Çelik E (2009) Alternative binders of diamond cutting tools. Ph.D. thesis
Fırat Uni. pp. 91, Elazığ
Ekincioğlu G (2017) Investigation of the effects on cutability parameters
of boron carbide doped diamond sockets in natural stone cutting
process. Ph.D. thesis, Süleyman Demirel Uni. Isparta, 157p
Ersoy A, AtıcıU (1999) Wear mechanisms of marble cutter. The 16th
mining congress of Turkey, pp 107115
Eyuboglu AS, Ozcelik Y, Kulaksiz S, Engin IC (2003) Statistical and
microscopic investigation of disc segment wear related to sawing
Ankara andesites. Intl J Rock Mech Min Sci 40:405414
GüneşYılmaz N (2013) Process efficiency comparison of a sandwich-
core sawblade and a conventional sawblade used in stone-machin-
ing. J Clean Prod 47:2631
GüneşYılmaz N, Göktan MR (2008) Effect of sawing rate on force and
energy requirements in the circular sawing of granites. Journal of
Engineering and Architecture of Eskişehir Osmangazi UnıXXI 2
Hwang KS, Yang TH, Hu SC (2005) Diamond cutting tools with a Ni
3
Al
matrix processed by reaction pseudo-hipping, vol 36A.
Metallurgical and Materials Transactions
Islak S, Kır D, Çelik H, Çelik E (2012) Effect of boron carbide on the
microstructure and the mechanical properties of segments produced
using hot pressing method. Sci Res Essays 7(23):20952103
Karaçay E (2008) Production of boron carbide and its characterization.
M.Sc. Thesis, Gazi Uni. Ankara, 118p
KarakuşA (1999) Examination of sawability parameters of quarrible
marbles in Diyarbakir Region. M.Sc. Thesis, Çukurova Uni.
Adana, 79p
Kır D (2012) Investigation of use of cubic boron nitride (CBN) as alter-
native abrasive in natural stone cutting tools. Ph.D. thesis,Fırat Uni.,
pp.107, Elazığ
Li Y, Huang H, Shen JY, Xu XP, Gao YS (2002) Cost-effective machin-
ing of granite by reducing tribological interactions. J Mater Process
Technol 129:389394
Luo SY, Liao YS (1995) Study of the behaviour of diamond saw-blades
in stone processing. J Mater Process Technol 51:296308
Ma QC, Zhang GJ, Kan YM, Xia YB, Wang PL (2010) Effect of addives
introduced by ball milling on sintering behavior and mechanical
properties of hot-pressed B
4
C ceramics. Ceram Int 36:167171
Öksüz KE, Şimşir M, Şahin Y (2011) Investigation of B
4
Cadditionsto
cutting tips produced by powder metallurgy and used for cutting
marble, vol 6. International Powder Metallurgy Conference and
Exhibition, pp 588591
Özay Ç, Hasçalık A (2004) Effect of C ratio on abrasive wear resistance
in Cu-C-Al2SiO5 composite produced by P/M method. Journal of
Science and Technology of Dumlupınar University 6:175184
Özçelik Y, Ünver B, Bayram F, YaşıtlıNE (2008) Sawability classifica-
tion of some natural stones with circular sawing and numerical
modelling of sawing mechanism. TÜBİTAK, Tur ke y
Özel S, Çelik E, Turhan H (2009) The investigation of microstructure and
mechanical properties of Cu-Al/B
4
C composıtes produced by usıng
Hot Pres. E-Journal of New World Sciences Academy 4(1)
Pierson HO (1996) Handbook of refractory carbides and nitrides. William
Andrew pub. Noyes
Polini W, Turchetta S (2005) Evaluation of diamond tool wear. Int J Adv
Manuf Technol 26:959964
Rahimian M, Ehsani N, Parvin N, Baharvandi HR (2009) The effect of
particle size, sintering temperature and sintering time on the proper-
ties of AlAl
2
O
3
composites. Made by powder metallurgy. J Mater
Process Technol 209:53875393
Şengün, N (2009) The effects of fracture toughness and brittleness of
rocks on sawing efficiency with circular discs. Ph.D. thesis,
Süleyman Demirel Uni., pp.165, Isparta,
Şengün N, AltındağR, Koçcaz CE (2009) The sawability analysis of
some magmatic rocks in Isparta region. DEÜ Uni. J Sci Eng 11:
2331
Şengün N, AltındağR, DemirdağS, Koççaz C E (2010) Assessment of
noise pollution in marble processing plants in terms of worker health
and related legislation. İ 12. Industrial Pollution Control
Symposium, 427432, Istanbul
Şengün N, AltındağR, DemirdağS (2013) Investigation of saw rotation
count and noise level changes in circular saw cutting process.
Pamukkale University Journal of Engineering Sciences 19:121121
Xu X (1999) Friction studies on the process in circular sawing of granites.
Tribol Lett 7:221227
Xu X, Yu Y (2005) Sawing performance of diamond with alloy coatings.
Surf Coat Technol 198:459463
Xu XP, Li Y, Zeng WY, Li LB (2002) Quantitative analysis of the loads
acting on the abrasive grits in the diamond sawing of granites. J
Mater Process Technol 129:5055
Yılmaz N (2009) Sawability analyses of magmatic-origin natural stones
using diamond segmented saws. Ph.D. thesis, Eskişehir Osmangazi
Uni., pp. 209, Eskişehir,
Yurdakul M, AkdaşH (2012) Prediction of specific cutting energy for
large diameter circular saws during natural stone cutting. Int J Rock
Mech Min Sci 53:3844
Arab J Geosci (2019) 12:170 Page 13 of 13 170
... In our previous study [12], MPs (UVW, P, HK, WWL) of the DS values were determined. The values of the parameters obtained are given in Table 1. ...
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The ball-milling process is a usual route employed to break up agglomerates in the powder or mix the powder with additives when preparing ceramics. Although it is well known that a powder can be “contaminated” by the wear particles from the milling balls, the study dealing with how the preparation and properties of a hard material would be affected by additives just introduced by scrape of milling balls has been scarce. In the present work, sintering behavior and mechanical properties of hot-pressed B4C with additives derived from milling balls were investigated. Polyoxymethylene, ZrO2, Al2O3 and Si3N4 were selected as different ball materials. The results show that the sinterability of B4C could be significantly enhanced because of the incorporation of one of these additives, i.e. ZrO2, Al2O3 and Si3N4 (approximately 3–6vol%). As a result of improvement in density, excellent mechanical properties of B4C ceramics were obtained. Among them a flexural strength of B4C added by ZrO2 reached 630MPa.
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Al2O3 is a major reinforcement in aluminum-based composites, which have been developing rapidly in recent years. The aim of this paper is to investigate the effect of alumina particle size, sintering temperature and sintering time on the properties of Al–Al2O3 composite. The average particle size of alumina were 3, 12 and 48μm. Sintering temperature and time were in the range of 500–600°C for 30–90min. A correlation is established between the microstructure and mechanical properties. The investigated properties include density, hardness, microstructure, yield strength, compressive strength and elongation to fracture. It has been concluded that as the particle size of alumina is reduced, the density is increased followed by a fall in density. In addition, at low particle size, the hardness and yield strength and compressive strength and elongation to fracture were higher, compared to coarse particles size of alumina. The variations in properties of Al–Al2O3 composite are dependent on both sintering temperature and time. Prolonged sintering times had an adverse effect on the strength of the composite.
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Circular sawing with diamond segmented sawblades is a machining process that represents a major cost item in the processing of marbles and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in stone processing industry. In this work, utilising a fully instrumented block-cutter, an experimental study was carried out to investigate the sawing performances of seven different types of marbles during circular sawing with a diamond segmented sawblade. The sawing tests were performed in the down-cutting mode. The two main sawing parameters, depth of cut and workpiece travel speed were varied in the pursuit of optimum sawing performance. Considering specific energy as a criterion of sawing efficiency, optimum sawing conditions valid for the tested marbles have been determined. Finally, statistically reliable equations were established to predict specific energy of sawing from simple laboratory rock property test procedures.
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An experimental study was carried out to evaluate quantitatively the loads acting on the diamond grits during the circular sawing of two kinds of typical granite with a diamond segmented saw blade. Measurements were made of the horizontal and vertical force components and the consumed power in order to obtain the tangential and the normal force components. The temperatures at the diamond–granite contact zone were measured using a foil thermocouple, the measurements, together with the net sawing power, being used subsequently to estimate the energy partition to the granite by a temperature matching technique. Based on the energy partition values, tip temperatures at individual cutting points were estimated using an analytical model. SEM was used to follow the topographies of worn diamond segments. The average force acting on each diamond grit was found to be only 4% of the diamond compressive strength measured by a static method. The strength disparity of diamond grits and the random protrusion of grits beyond the bond matrix should be significant factors in accounting for the wear of diamond grits. The wear of diamond grits was also found to be closely related to the high temperatures generated at individual cutting points and the pop-out of diamonds from the bond matrix were attributed to the heat conducted to the segments.