On Abrasive Flow Finishing of Straight Bevel Gear
101
Table 2 Result of Phase-2
experiment
Exp. No.
Finishing time ‘t’
(minutes)
Responses
ΔR a (µm)
ΔR max (µm)
1
10
0.02
0.04
2
15
0.06
0.11
3
20
0.08
0.17
4
25
0.11
0.23
5
30
0.15
0.39
6
35
0.14
0.37
7
40
0.09
0.26
Fig. 2 Variation of change in maximum surface roughness and average surface roughness with
finishing time
approximately equal heights after 15 min of finishing. During 20–30 min of finishing
changes in surface roughness, values increase rapidly. They attain their maximum
values at 30 min of finishing time corresponding to experiment no.5 (i.e. their max.
and avg. surface roughness values after AFF attain their minimum values) due to the
availability of surface roughness peaks of approximately equal heights. Changes in
surface roughness values start decreasing for finishing time beyond 30 min because
cutting edges of the abrasive particles get blunted.
Therefore, finishing time of 30 min and extrusion pressure of 5 MPa were identified as optimum parametric combination which yield higher reduction in max.
and avg. surface roughness. The workpiece straight bevel gear finished at finishing
time of 30 min and extrusion pressure of 5 MPa considered fine finished straight