540
A. Jadhav and S. Kumar
Table 1 Maximum chemical composition for AISI 304 material
C
Ni
Cr
Si
Mn
P
S
Fe
0.08
0.1
18–20
0.75
2.0
0.045
0.030
Balance
Table 2 Mechanical properties for AISI 304 material
Mechanical properties
Values
Density (kg/m 3 )
8.03
Yield strength (N/mm 2 )
215
Tensile strength (N/mm 2 )
505
Hardness (HRC)
70
Elongation (%)
70
Table 3 Levels of laser cutting parameters
Symbol
Parameters
Level 1
Level 2
A
Laser power (W)
5000
5500
B
Cutting speed (mm/min)
210
230
C
Gas pressure (bar)
8
12
For the current study, process parameters considered are laser power (LP), cutting
speed (CS), and gas pressure (GP). Table 3 shows levels of laser cutting parameters
which are considered based on literature review. To identify the experimental conditions, some trial runs were executed out to identify range of input process parameters.
To avoid material surface melting, proper precaution was taken. Experimental design
includes two levels and five center points. A total of 17 experiments are carried out
according to design suggested by design expert software V11. To design experiments,
response surface methodology (RSM) using two levels Box-Behnken (BBD) design
is used. BBD provides modelling of the response surface. It is selected due to the
shorter range of input process parameters as compared to central composite design
(CCD). In this, all involved parameters are simultaneously at their highest and lowest
stage. Due of this experiments underneath very extreme conditions can be avoided.
After experimentation, the dross height at the bottom of surface of all samples is
measured. Images of the top side surface are captured using high resolution camera
(Canon DCC, Model-242S821), and mean average of three measurements readings
for every run is noted. Then, dross height is measured using commercial software
“Image J.” Experimental design data and the measured values of dross height are
listed in Table 4.
A. Jadhav and S. Kumar
Table 1 Maximum chemical composition for AISI 304 material
C
Ni
Cr
Si
Mn
P
S
Fe
0.08
0.1
18–20
0.75
2.0
0.045
0.030
Balance
Table 2 Mechanical properties for AISI 304 material
Mechanical properties
Values
Density (kg/m 3 )
8.03
Yield strength (N/mm 2 )
215
Tensile strength (N/mm 2 )
505
Hardness (HRC)
70
Elongation (%)
70
Table 3 Levels of laser cutting parameters
Symbol
Parameters
Level 1
Level 2
A
Laser power (W)
5000
5500
B
Cutting speed (mm/min)
210
230
C
Gas pressure (bar)
8
12
For the current study, process parameters considered are laser power (LP), cutting
speed (CS), and gas pressure (GP). Table 3 shows levels of laser cutting parameters
which are considered based on literature review. To identify the experimental conditions, some trial runs were executed out to identify range of input process parameters.
To avoid material surface melting, proper precaution was taken. Experimental design
includes two levels and five center points. A total of 17 experiments are carried out
according to design suggested by design expert software V11. To design experiments,
response surface methodology (RSM) using two levels Box-Behnken (BBD) design
is used. BBD provides modelling of the response surface. It is selected due to the
shorter range of input process parameters as compared to central composite design
(CCD). In this, all involved parameters are simultaneously at their highest and lowest
stage. Due of this experiments underneath very extreme conditions can be avoided.
After experimentation, the dross height at the bottom of surface of all samples is
measured. Images of the top side surface are captured using high resolution camera
(Canon DCC, Model-242S821), and mean average of three measurements readings
for every run is noted. Then, dross height is measured using commercial software
“Image J.” Experimental design data and the measured values of dross height are
listed in Table 4.