NIMIC 80a Lab Report
2. Experimental Details
2.1. Work piece Material
The material used for the experiment is NIMONIC 80A round bar of 80 mm diameter and 250 mm length. The chemical composition is given in Table 1.
Table 1. Chemical composition of NIMONIC 80A
Ni Cr Ti Al Co Fe Si Cu C Mn
Bal 18.88 1.98 1.33 1.34 1.99 0.68 0.11 0.045 0.77
Fig. 1. NIMONIC 80A round bar
2.2. Tool Material
The turning experiments were conducted using SiAlON ceramic inserts. Grade SN800 is used. SiAlON ceramic inserts of CNGA120408 geometry is used. It has 0º clearance angle, – 5º side cutting edge angle and 80º rhombus shape with nose radius of 0.8 mm. The tool holder used for clamping the insert is MCLNL 2525 M12 (Make- WIDIA). It has 95º approach angle and – 6º back …show more content…
2. Ceramic insert
2.3. Machines and Equipments used Fig. 3. Experimental set up
The machine used for turning of NIMONIC 80A is ACE CNC LATHE JOBBER XL. The instrument used for measuring surface roughness is SJ 301stylus type surface roughness tester developed for shop floor use. Nikon measuring microscope is used to measure flank wear and chip thickness.
2.4. Taguchi Method
The Taguchi method, which uses a special design of orthogonal arrays to study the entire parameter space with a small number of experiments, only is a suitable substitute. To obtain better machining performance in turning, the parameter design proposed by the Taguchi method is adopted in this experimental work.
A stepwise procedure of the Taguchi parameter design is described below [9] Identification of the quality characteristics and selection of design parameters to be evaluated; Determination of the number of levels for the design parameters and possible interactions between the design parameters; Selection of the appropriate orthogonal array and assignment of design parameters to the orthogonal array; Conducting the experiments based on design of the orthogonal array; Analysis of the experimental results using S/N ratio and ANOVA …show more content…
The total sum of squares SST from the S/N ratio (η) can be calculated as [10]
SST = ∑_(i=1)^m▒〖(η_i-η_m)〗^2
Where, m is the number of experiments, ηi is the mean S/N ratio for the ith experiment and ηm is the total mean of S/N ratio.
The total sum of squared deviation SST is divided into two parts: the sum of the squared deviation SSp due to each process parameter and sum of squared error SSe. SSp can be calculated as
SSp = ∑_(j=1)^t▒〖〖〖(sn〗_j)〗^2/t-1/m[〖∑_(i=1)^m▒η_i ]〗^2 〗
Where p is the one of the experiment parameters, j is the level number of this parameter p, t is the repetition of each level of parameter p and snj is the sum of the S/N ratio involving this parameter p and level j.
The sum of squares from parameters SSe is
SSe = SST – SSA – SSB – SSC
Where, SSe is sum of squares for error, SST is total sum of squares, and SSA , SSB , SSC are sum of squares for parameters A, B, C respectively.
The total degree of freedom of tested parameter Dp = t -1. The variance of the parameter tested is Vp = SSp /Dp. The F value for each design parameter is simply the ratio of the mean of squares error (Fp=Vp /Ve). The corrected sum of squares Sp can be calculated
2.1. Work piece Material
The material used for the experiment is NIMONIC 80A round bar of 80 mm diameter and 250 mm length. The chemical composition is given in Table 1.
Table 1. Chemical composition of NIMONIC 80A
Ni Cr Ti Al Co Fe Si Cu C Mn
Bal 18.88 1.98 1.33 1.34 1.99 0.68 0.11 0.045 0.77
Fig. 1. NIMONIC 80A round bar
2.2. Tool Material
The turning experiments were conducted using SiAlON ceramic inserts. Grade SN800 is used. SiAlON ceramic inserts of CNGA120408 geometry is used. It has 0º clearance angle, – 5º side cutting edge angle and 80º rhombus shape with nose radius of 0.8 mm. The tool holder used for clamping the insert is MCLNL 2525 M12 (Make- WIDIA). It has 95º approach angle and – 6º back …show more content…
2. Ceramic insert
2.3. Machines and Equipments used Fig. 3. Experimental set up
The machine used for turning of NIMONIC 80A is ACE CNC LATHE JOBBER XL. The instrument used for measuring surface roughness is SJ 301stylus type surface roughness tester developed for shop floor use. Nikon measuring microscope is used to measure flank wear and chip thickness.
2.4. Taguchi Method
The Taguchi method, which uses a special design of orthogonal arrays to study the entire parameter space with a small number of experiments, only is a suitable substitute. To obtain better machining performance in turning, the parameter design proposed by the Taguchi method is adopted in this experimental work.
A stepwise procedure of the Taguchi parameter design is described below [9] Identification of the quality characteristics and selection of design parameters to be evaluated; Determination of the number of levels for the design parameters and possible interactions between the design parameters; Selection of the appropriate orthogonal array and assignment of design parameters to the orthogonal array; Conducting the experiments based on design of the orthogonal array; Analysis of the experimental results using S/N ratio and ANOVA …show more content…
The total sum of squares SST from the S/N ratio (η) can be calculated as [10]
SST = ∑_(i=1)^m▒〖(η_i-η_m)〗^2
Where, m is the number of experiments, ηi is the mean S/N ratio for the ith experiment and ηm is the total mean of S/N ratio.
The total sum of squared deviation SST is divided into two parts: the sum of the squared deviation SSp due to each process parameter and sum of squared error SSe. SSp can be calculated as
SSp = ∑_(j=1)^t▒〖〖〖(sn〗_j)〗^2/t-1/m[〖∑_(i=1)^m▒η_i ]〗^2 〗
Where p is the one of the experiment parameters, j is the level number of this parameter p, t is the repetition of each level of parameter p and snj is the sum of the S/N ratio involving this parameter p and level j.
The sum of squares from parameters SSe is
SSe = SST – SSA – SSB – SSC
Where, SSe is sum of squares for error, SST is total sum of squares, and SSA , SSB , SSC are sum of squares for parameters A, B, C respectively.
The total degree of freedom of tested parameter Dp = t -1. The variance of the parameter tested is Vp = SSp /Dp. The F value for each design parameter is simply the ratio of the mean of squares error (Fp=Vp /Ve). The corrected sum of squares Sp can be calculated