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Engineering, Technology & Applied Science Research Vol. 11, No. 5, 2021, 7551-7557 7551 
 

www.etasr.com Khanh & Cuong: Parameter Selection to Ensure Multi-Criteria Optimization of the Taguchi Method … 

 

Parameter Selection to Ensure Multi-Criteria 
Optimization of the Taguchi Method Combined with 
the Data Envelopment Analysis-based Ranking 

Method when Milling SCM440 Steel  
 

Nguyen Lam Khanh 
Faculty of Mechanical Engineering  

University of Transport and Communications 
Hanoi, Vietnam 

khanh_mxd@utc.edu.vn 

Nguyen Van Cuong 
Faculty of Mechanical Engineering  

University of Transport and Communications 
Hanoi, Vietnam 

nguyencuong@utc.edu.vn 
 

 

Abstract-SCM440 steel is a commonly used material for making 

plastic injection molds and components such as gears, 

transmission shafts, rolling pins, etc. Surface roughness has a 
direct influence on the workability and durability of the parts 

and/or components, while the Material Removal Rate (MRR) is a 

parameter that is used to evaluate the productivity of the 

machining process. Furnished products with small surface 

roughness and large MRR is the desired result by all milling 

processes. In this paper, the determination of the values of input 
parameters is studied in order to ensure that during the process 

of milling SCM440 steel, it will have the smallest surface 

roughness and the largest MRR. There are five parameters that 

are required to be determined, namely the cutting insert 

material, the tool nose radius, the cutting speed, the feed rate, 

and the cutting depth. The Taguchi method was applied to design 

the experimental matrix with a total of 27 experiments. Result 
analysis determined the influence of the input parameters on 

surface roughness and MRR. The Data Envelopment Analysis-

based Ranking (DEAR) method was applied to determine the 

optimal value of the input parameters, which were used to 

conduct the milling experiments to re-evaluate their suitability. 

Keywords-milling; SCM440 steel; surface roughness; MRR; 
optimization; Taguchi; DEAR   

I. INTRODUCTION  

Milling is a very common machining method in the 
mechanical engineering industry. It is considered to be the 
cutting method with the highest productivity. With the 
development of the cutting tool manufacturing technology as 
well as the emergence of the modern CNC machines, this 
method is capable of ensuring very high accuracy. Research of 
solutions that improve the accuracy of milling machines and 
milling cutters is continuously conducted [1]. Therefore, in 
some cases, this method is used as the final machining method 
for surfaces requiring high precision [2]. To make the most use 
of the achievements in the mechanical engineering technology 
and the cutting tool manufacturing technology, many 
researchers carried out experimental studies to determine the 
optimal value of parameters related to the machining process. 

The purpose of these studies is to determine the value of the 
machining process’s parameters to ensure minimum surface 
roughness and maximum Material Removal Rate (MRR). This 
problem is known as milling operations optimization. When 
studying the milling operations optimization, many authors 
used the Taguchi method to design the experimental matrix. 
When comparing the Taguchi-based matrix design method with 
some other matrix design methods, it was found that the 
Taguchi method requires a smaller number of experiments. An 
advantage that only the Taguchi method possesses is that it can 
design a matrix with the input parameters being a qualitative 
(not a quantitative) parameter [3, 4].  

In [5], the Taguchi method was applied to design the 
experimental matrix when milling the AA6082T6 material by a 
tungsten carbide cutting tool. Signal-to-Noise (S/N) ratio was 
analyzed to determine the optimal values of spindle speed, feed 
rate, and depth of cut to ensure the minimum value of surface 
roughness. The Taguchi method was also used to design the 
experimental matrix when milling AA6082T6 with PVD-
coated and CVD-coated cutting tools. The determination of 
cutting speed, feed rate, and tool material type to ensure tool 
wear was similarly performed for surface roughness in [6]. In 
[7], the authors applied the Taguchi method to design the 
experimental matrix when milling D2 steel with the carbide 
inserts cutting tool. Cutting parameters including spindle speed, 
feed rate, and depth of cut were selected as input parameters for 
each experiment. The S/N ratio analysis method was applied to 
determine the optimal value of the cutting parameters to ensure 
the minimum value of surface roughness. When milling AISI 
P20 steel with the carbide inserts cutting tool, the authors in [8] 
used the Taguchi method to design an experimental matrix with 
spindle speed, feed rate, and depth of cut as input parameters 
[8]. They also used S/N ratio analysis to determine the optimal 
value of the input parameters to ensure the minimum value of 
surface roughness. To determine the optimal value of 
parameters including cutting speed, feed, radial depth, and 
axial depth to ensure the minimum value of surface roughness 
when milling 1.2738 steel with the WNHU 04T310 cutting tool 

Corresponding author: Nguyen Van Cuong



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(manufactured by Palbit), the authors in [9] also applied the 
Taguchi method to design the experimental matrix. The S/N 
ratio analysis method was applied to determine the optimal 
value of the cutting parameters. Authors in [10] also designed 
the experimental matrix according to the Taguchi method when 
milling 7075T6 aluminum alloy with an AlTiN PVD-coated 
cutting tool. The optimal values of cutting speed, feed rate, 
radial depth, and axial depth were also determined by the 
analysis of the S/N ratio. This study also aimed to ensure the 
minimum value of surface roughness. To determine the 
optimum value of cutting speed, feed rate, depth of cut, and 
coolant flow to ensure the minimum value of surface roughness 
when milling AISI 1040 MS steel with the carbide inserts 
cutting tool, the authors in [11] also designed the experimental 
matrix according to the Taguchi method and the S/N ratio 
analysis method was also used to determine the optimal value 
of the input parameters. Authors in [12] also designed the 
experimental matrix according to the Taguchi method when 
milling 7075 T6 aluminum alloy with a High-Speed Steel 
(HSS) cutting tool. They also applied the S/N ratio analysis 
method to determine two sets of optimal values of cutting 
speed, feed rate, and depth of cut, one set that ensures the 
smallest surface roughness and another set that ensures the 
largest MRR. 

The experimental matrix design based on the Taguchi 
method has been successfully applied in a number of studies to 
ensure a certain criterion of the machining process. However, if 
only the Taguchi method is applied for the experimental design 
and the S/N ratio analysis to determine the optimal value of the 
machining process parameters, only one criterion of the 
machining process can be guaranteed. In order to resolve this 
shortcoming of the Taguchi method, many studies combined 
the Taguchi method with other methods to optimize the multi-
objectives of the milling process: in [13], the Taguchi method 
has been combined with ANOVA to determine the values of 
the spindle speed, the feed rate and the cutting depth to ensure 
the minimum surface roughness and the maximum MRR when 
milling AISI 1005 steel with the TiN coated cutting tool. In 
[14], the Taguchi method and the Weighted Principal 
Component Analysis (WPCA) were combined to determine the 
milling type and the values of milling parameters to 
simultaneously ensure minimum surface roughness and 
maximum MRR when milling Al 6061 aluminum alloy with a 
high speed steel cutting tool. The Taguchi method and the Gray 
Relational Analysis (GRA) method were combined to 
determine the values of cutting speed, feed rate, and cutting 
depth to ensure simultaneously minimum surface roughness 
and maximum MRR when milling Inconel 718 super alloy by 
an uncoated tungsten carbide cutting tool in [15]. A 
combination of the Taguchi method, TOPSIS method, and 
ANOVA analysis was performed to determine the optimal 
values of cutting speed, feed rate, and depth of cut to ensure 
simultaneously the minimum value of surface roughness and 
maximum value of MRR when milling Ti-6Al-4V titanium 
alloy with TiN coated cutting tools in [16]. Through the above 
studies, it is shown that the cutting tool parameters are 
commonly selected as the input parameters of the milling 
experiment process. These parameters can be easily adjusted by 
the operators. However, to the best of our knowledge, there 

have been no studies that consider all the 5 parameters of the 
cutting tool material, i.e. the insert material, the tool nose 
radius, the cutting speed, the feed rate, and the depth of cut. 

SCM440 steel is a type of steel used quite commonly to 
make plastic injection molds and components such as gears, 
transmission shafts, and rolling pins [17]. Due to the high 
content of Cr, Mo and Mn elements, this steel has a low 
thermal conductivity. When machining this steel, the tool wears 
out quickly, thus it is required to select the right cutting tool 
[18-20]. A number of studies on milling steels equivalent to 
this steel have been carried out [17-23]. However, to the best of 
our knowledge, there are no published studies on milling 
SCM440 (or equivalent) steel that consider all 5 parameters. 
DEAR is a method used for multi-criteria decision making that 
was introduced in 2002 [24]. This method has been used for the 
multi-objective optimization of the AISI 1055 steel turning 
process [25], the Ti-6Al-4V alloy turning process [26], the 
SAE420 steel grinding with a segmented grinding wheel [27], 
of the Electrical Discharge Machining (EDM) with the material 
type AA 6082 [26], etc. However, to the best of our 
knowledge, there have been no published studies on the 
application of this method in multi-criteria decision making for 
milling methods in general and for milling SCM440 steel in 
particular. 

In this study, milling parameters such as the cutting tool 
material, the tool nose radius, the cutting speed, the feed rate, 
and the cutting depth will be determined to simultaneously 
ensure the optimization of two criteria, minimum surface 
roughness and maximum MRR when milling this type of steel. 
A combination of the Taguchi method and the DEAR method 
was used to solve this problem.  

II. THE DEAR METHOD  

The purpose of the experimental process of this study is to 
ensure that surface roughness (Ra) has the smallest value and 
the MRR reaches the maximum value. Thus, it is required to 
determine the values of the input parameters that ensure the set 
out objectives. The DEAR method will be applied in this study 
to carry out the above-stated work [24]. The DEAR method's 
steps are [24]: 

• Determine the weight of each response for all experiments. 
This value is calculated as the ratio of the value of each 
response to the sum of all responses. 

• Transfer the response data to the weight data by multiplying 
the observed data by their respective weight. 

• Divide the inversed data by the sum of all inversed data. 

• The Multi Response Performance Index (MRPI) is 
calculated by (1): 

���� =	��	 ∗	�� +	�
�� ∗ 	���    (1) 

The weights of the responses are calculated as: 

��	 =
�	

∑�	
    (2) 

�
�� =

�

���

∑
�

���

    (3) 



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III. EXPERIMENTS ON MILLING SCM400 STEEL  

A. Experimental System  

A CNC milling machine with the HAA5 serial was used to 
carry out the experiments (Figure 1). The experimental sample 
is SCM400 steel with length, width, and height of 80mm, 
40mm, and 30mm respectively. The steel’s chemical 
composition conducted with a spectrometer was: 0.43% C, 
0.28% Si, 0.72% Mn, 1.05% Cr, 0.23% Mo, 0.024% P, and 
0.026% S. 

 

 
Fig. 1.  The milling  machine. 

TABLE I.  PARAMETERS OF THE CUTTING INSERTS 

Parameter 

Cutting insert 

R390-

11T303M

-PM1025 

R390-

11T305M-

PM1025 

R390-

11T305M

-PM1025 

Tool nose radius (mm) 0.3 0.5 0.8 
Back edge length (mm) 0.8 0.9 1.2 

Weight (kg) 0.0022 0.0026 0.003 
Coating material TiN; TiCN; TiAlN 

Cutting thickness (mm) 3.59 
Main cutting angle (degree) 90 
Maximum cutting depth (mm) 10 
Shape style of cutting piece L 

Edge width (mm) 6.8 
Effective length of edge (mm) 10 

 
Three types of cutting pieces were used in the experiment 

namely the TiN-, TiCN-, and TiAlN-coated pieces. These 
cutting pieces have high thermal resistance, and have been 
proven to be very suitable for machining SCM440 steel. Each 
cutting piece was used with 3 tool nose radius values of 
0.3mm, 0.5mm, and 0.8mm. On the tool shank with 12mm 
diameter, 2 symmetrical cutting pieces were installed. Each 
cutting insert was used only once for the purpose of eliminating 
the influence of tool wear on the output parameters of the 
milling process. In other words, the number of cutting inserts 
used in the experiment is twice the number of experiments to 
be carried out. The milling process has been carried out 
according to the method of symmetric milling, which means 
that the milling width was equal to the diameter of the milling 
cutter. Table I shows some basic parameters of the cutting 
inserts used. 

The surface roughness was measured with a Mitutoyo - 
Japan SJ301 surface roughness tester of 0.8mm standard 
length. The surface roughness of each experimental sample 
was determined by averaging at least three consecutive 
measurements. The MRR was calculated according to: 

��� = �� ∙ �� ∙ ��	 (mm
3/min)    (4) 

where �� is the feed rate (mm/min), ��  is the cutting depth 
(mm), and �� is the cutting width (mm). In this case the cutting 
width is just equal to the diameter of the milling cutter. 

B. Experimental Design 

The Taguchi method was applied to design the 
experimental process in this study. Five parameters were 
selected as the input parameters of the experimental process,. 
Each selected parameter has three levels of values 
(corresponding to three encoding degrees of 1, 2, and 3). The 
values of the experimental parameters, selected within their 
range as recommended by the cutting tool manufacturer [29], 
are shown in Table II. 

TABLE II.  INPUT PARAMETERS 

Parameter Symbol Unit 
Value at level 

1 2 3 

Insert material IM - TiN TiCN TiAlN 
Tool nose radius r mm 0.3 0.5 0.8 
Cutting speed Vc m/min 80 120 160 
Feed rate Vf mm/min 250 320 390 
Depth of cut ap mm 0.20 0.30 0.40 

 

The Taguchi method was used to design the experimental 
matrix. When comparing the matrix design method by the 
Taguchi method with some other matrix design methods, it can 
be found that it requires a smaller number of experiments. For 
example, with 5 input parameters, in which each parameter has 
3 levels of values, the Taguchi method only needs 27 
experiments while the Box-Behnken design needs at least 46 
experiments and the Central Composite Design (CCD) method 
needs a minimum of 43 experiments. An advantage that only 
the Taguchi method obtains is that it allows designing the 
experimental matrix with input parameters that are not 
quantitative parameters. In this case the qualitative parameter is 
just the cutting insert material type. So, the experimental matrix 
was designed according to the Taguchi method with a total of 
27 experiments, as shown in Table III. 

IV. RESULTS AND DISCUSSION  

The experiments in Table III are given in accordance with 
the results shown in Table IV. Figure 2 shows the influence of 
the input parameters on surface roughness. The comparison of 
the difference at the lowest and highest levels, i.e. between 
level 1 and level 3 of the parameter line graph (red broken line) 
shows that the tool nose radius is the parameter that has the 
greatest influence on surface roughness, followed by the 
influence of the cutting insert material and the feed rate. The 
difference of the line graph of cutting speed and cutting depth 
is very small, showing that these two parameters have 
negligible influence on surface roughness. 



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TABLE III.  EXPERIMENTAL MATRIX 

No. 
Code value Actual value 

IM r Vc Vf ap IM r (mm) Vc (m/min) Vf (mm/min) ap (mm) 

1 1 1 1 1 1 TiN 0.3 80 250 0.2 
2 1 1 1 1 2 TiN 0.3 80 250 0.4 
3 1 1 1 1 3 TiN 0.3 80 250 0.6 
4 1 2 2 2 1 TiN 0.5 120 320 0.2 
5 1 2 2 2 2 TiN 0.5 120 320 0.4 
6 1 2 2 2 3 TiN 0.5 120 320 0.6 
7 1 3 3 3 1 TiN 0.8 160 390 0.2 
8 1 3 3 3 2 TiN 0.8 160 390 0.4 
9 1 3 3 3 3 TiN 0.8 160 390 0.6 
10 2 1 2 3 1 TiCN 0.3 120 390 0.2 
11 2 1 2 3 2 TiCN 0.3 120 390 0.4 
12 2 1 2 3 3 TiCN 0.3 120 390 0.6 
13 2 2 3 1 1 TiCN 0.5 160 250 0.2 
14 2 2 3 1 2 TiCN 0.5 160 250 0.4 
15 2 2 3 1 3 TiCN 0.5 160 250 0.6 
16 2 3 1 2 1 TiCN 0.8 80 320 0.2 
17 2 3 1 2 2 TiCN 0.8 80 320 0.4 
18 2 3 1 2 3 TiCN 0.8 80 320 0.6 
19 3 1 3 2 1 TiAlN 0.3 160 320 0.2 
20 3 1 3 2 2 TiAlN 0.3 160 320 0.4 
21 3 1 3 2 3 TiAlN 0.3 160 320 0.6 
22 3 2 1 3 1 TiAlN 0.5 80 390 0.2 
23 3 2 1 3 2 TiAlN 0.5 80 390 0.4 
24 3 2 1 3 3 TiAlN 0.5 80 390 0.6 
25 3 3 2 1 1 TiAlN 0.8 120 250 0.2 
26 3 3 2 1 2 TiAlN 0.8 120 250 0.4 
27 3 3 2 1 3 TiAlN 0.8 120 250 0.6 

 

TABLE IV.  EXPERIMENTAL RESULTS 

No IM r (mm) Vc (m/min) Vf (mm/min) ap (mm) Ra (µm) MRR (mm
3
/min) 

1 TiN 0.3 80 250 0.2 0.771 600 
2 TiN 0.3 80 250 0.4 1.457 1200 
3 TiN 0.3 80 250 0.6 1.697 1800 
4 TiN 0.5 120 320 0.2 1.538 768 
5 TiN 0.5 120 320 0.4 0.905 1536 
6 TiN 0.5 120 320 0.6 0.986 2304 
7 TiN 0.8 160 390 0.2 2.205 936 
8 TiN 0.8 160 390 0.4 1.582 1872 
9 TiN 0.8 160 390 0.6 0.863 2808 
10 TiCN 0.3 120 390 0.2 1.024 936 
11 TiCN 0.3 120 390 0.4 1.112 1872 
12 TiCN 0.3 120 390 0.6 0.801 2808 
13 TiCN 0.5 160 250 0.2 1.076 600 
14 TiCN 0.5 160 250 0.4 2.908 1200 
15 TiCN 0.5 160 250 0.6 1.014 1800 
16 TiCN 0.8 80 320 0.2 0.985 768 
17 TiCN 0.8 80 320 0.4 3.019 1536 
18 TiCN 0.8 80 320 0.6 1.549 2304 
19 TiAlN 0.3 160 320 0.2 0.927 768 
20 TiAlN 0.3 160 320 0.4 0.877 1536 
21 TiAlN 0.3 160 320 0.6 0.892 2304 
22 TiAlN 0.5 80 390 0.2 1.234 936 
23 TiAlN 0.5 80 390 0.4 1.929 1872 
24 TiAlN 0.5 80 390 0.6 0.824 2808 
25 TiAlN 0.8 120 250 0.2 0.545 600 
26 TiAlN 0.8 120 250 0.4 1.549 1200 
27 TiAlN 0.8 120 250 0.6 1.601 1800 

 
Because the cutting insert material, the tool nose radius and 

the cutting speed do not exist in the MRR calculation formula 
(4), they have no influence on MRR. Figure 3 shows the 

influence of the feed rate and the cutting depth on MRR. The 
difference between level 1 and level 3 of cutting depth line 
graph is greater than the one of the feed rate line graph. This 



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shows that the cutting depth has a greater influence on MRR 
than the feed rate. Thus, we see that the influence of the input 
parameters on surface roughness and MRR is different, even 
adverse, e.g. the tool nose radius has a great influence on 
surface roughness without any influence on MRR, the feed rate 
and the cutting depth are two parameters needed for calculating 
the MRR, but they do not significantly affect surface 
roughness, etc. Thus, it can be said that being based only on the 
two graphs of Figures 2 and 3, limits the determination of the 
values of the input parameters to ensure minimum surface 
roughness and maximum MRR. Table IV shows that surface 
roughness has the smallest value in experiment #25, while 
MRR has the maximum value in experiments #9, #12 and #24. 
Thus, if we only observe Table IV, it is not possible to 
determine the value of the input parameters to ensure both 
minimum surface roughness and maximum MRR. The DEAR 
method will be used to solve this problem in the next section. 

 

 
Fig. 2.  Main effect plot for surface roughness. 

 
Fig. 3.  Main effect plot for MRR. 

V. SELECTION OF THE VALUE OF THE INPUT PARAMETERS  

From the experimental data in Table IV, the weights of the 
responses and the MRPI value at each experiment are 
calculated according to (1) - (3), as shown in Table V. From the 
data in Table V, the MRPI values of all input parameters at all 
degrees were calculated. This value is calculated as the sum of 
the MRPI value of each parameter at the respective degree, as 
shown in Table VI. From the data in Table VI, it can be seen 
that the cutting insert material (IM) has the smallest value of 
MRPI corresponding to level 3, tool nose radius (r) has the 
smallest value of MRPI corresponding to level 1, cutting speed 

(��) corresponding to level 2, and feed rate (��) and cutting 
depth (��) corresponding to level 3. Thus, the optimal value of 
the parameters of the cutting insert material, the tool nose 
radius, the cutting speed, the feed rate, and the cutting depth are 
TiAlN, 0.3mm, 120m/min, 390mm/min, and 0.6mm 
respectively [24]. The MRPI value with the maximum Max-
Min of 0.52972 is the cutting depth. Thus, the cutting depth is 
the parameter that has the greatest influence, followed by the 
tool nose radius, the cutting insert material, the cutting speed, 
and the feed rate [24]. 

TABLE V.  EXPERIMENTAL RESPONSE WEIGHT AND MRPI 

No. ��� ���� MRPI 
1 0.02168 0.07506 45.05364 
2 0.04096 0.03753 45.09661 
3 0.04771 0.02502 45.11789 
4 0.04324 0.05864 45.10343 
5 0.02544 0.02932 45.05996 
6 0.02772 0.01955 45.06426 
7 0.06199 0.04812 45.17362 
8 0.04448 0.02406 45.10729 
9 0.02426 0.01604 45.05787 
10 0.02879 0.04812 45.06641 
11 0.03126 0.02406 45.07169 
12 0.02252 0.01604 45.05497 
13 0.03025 0.07506 45.06948 
14 0.08175 0.03753 45.27467 
15 0.02851 0.02502 45.06584 
16 0.02769 0.05864 45.06421 
17 0.08487 0.02932 45.29317 
18 0.04355 0.01955 45.10439 
19 0.02606 0.05864 45.06109 
20 0.02466 0.02932 45.05855 
21 0.02508 0.01955 45.05930 
22 0.03469 0.04812 45.07974 
23 0.05423 0.02406 45.14154 
24 0.01473 0.01604 45.04465 
25 0.01532 0.07506 45.04528 
26 0.04355 0.03753 45.10439 
27 0.04501 0.02502 45.10899 

TABLE VI.  TOTAL MRPI 

Parameter 
Level Max - Min 

1 2 3  

IM 405.83457 406.06482 405.70353 0.36129 
r 405.64016 405.90357 406.05920 0.41904 
Vc 405.99584 405.67938 405.92771 0.31646 
Vf 405.93679 405.86835 405.79778 0.13901 
ap 405.71690 406.20787 405.67815 0.52972 

 

VI. EXPERIMENTS WITH THE OPTIMAL VALUES OF THE 
PARAMETERS  

The optimal set of the 5 input parameters defined above 
was used to experiment on the milling process with 3 steel 
samples. The surface roughness of each experimental sample is 
shown in Table VII. The MRR value at each experiment has 
also been calculated and is included in this Table. The average 
value of surface roughness in these cases is 0.724µm. If 
compared with the surface roughness values in Table IV, it can 
be seen that although 0.724µm is still larger than the value of 
surface roughness at experiment #25, this value is very small 



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when compared to the total of 27 experiments that were carried 
out. For MRR, when calculated according to (4), in the three 
test samples, the MRR is equal to 2808mm3/min, which is also 
larger than the data in Table IV. From that, it can be seen that 
when machining with the optimal values of the input 

parameters, MRR reaches its maximum value and surface 
roughness is also significantly improved. This result ensures 
the reliability when using the optimal value of the input 
parameters and proves the success in using the DEAR method 
in this study. 

TABLE VII.  OUTPUT PARAMETERS WHEN EXPERIMENTING WITH THE OPTIMAL VALUES OF THE INPUT PARAMETERS 

No. 
Optimization value 

Ra (µµµµm) MRR (mm
3
/min) 

IM r (mm) Vc (m/min) Vf (mm/min) ap (mm) 

1 
TiAlN 0.3 120 390 0.6 

0.726 2808 
2 0.721 2808 
3 0.725 2808 

Mean 0.724 2808 
 

VII. CONCLUSION  

An experimental process of milling SCM 440 steel was 
carried out in this study. Three types of cutting inserts were 
used, coated with TiN, TiCN, and TiAlN. The tool nose radius, 
the cutting speed, the feed rate, and the cutting depth were also 
determined as input parameters of the experimental process. 
The DEAR method was applied to determine the optimal value 
of the input parameters. Some of the conclusions drawn from 
this study are: 

• The tool nose radius is the parameter that has the greatest 
influence on surface roughness, followed by the influence 
of the cutting insert material and the feed rate. The cutting 
speed and the cutting depth have no significant influence on 
surface roughness. 

• Only the feed rate and the cutting depth have an influence 
on MRR, and the influence of the cutting depth on MRR is 
greater than the one of the feed rate. 

• The parameter set that ensures simultaneously the two 
objectives is: TiAlN cutting insert material, 0.3mm tool 
nose radius, 120mm/min cutting speed, 390mm/min feed 
rate, and 0.6mm cutting depth. 

• DEAR method was not only successful in determining the 
optimal values of the input parameters in this study as well 
as in [25-28] but it is also quite promising to being 
successful in the future when applied to determine the value 
of input parameters to simultaneously ensure multi-criteria 
optimization of the machining process. 

ACKNOWLEDGMENT 

This research is funded by University of Transport and 
Communications (UTC) under the grant number T2021-CK-
003. 

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