Tensile Strength Lab Report

CHAPTER 4 RESULTS & DISCUSSION
4.1 ULTIMATE TENSILE STRENGTH
In the first run nine experiments are performed and tensile strength is calculated on the universal testing machine as shown in the table: 4.1.
Table 4.1: Tensilestrength Trial 1 of the Specimens for Single Sided Joint
Speed(r.p.m) Sample No. Feed (mm/min.) Shoulder Diameter
(mm) Area
(mm2) Load
(KN) Tensile strength Trial1 (KN/mm2)
1950 S1 20 16 150 9 0.06 S2 25 18 150 11.25 0.075 S3 30 20 150 18.5 0.121
3080 S4 20 18 150 20 0.133 S5 25 20 150 23.7 0.152 S6 30 16 150 17.5 0.116
4600 S7 20 20 150 17.25 0.115 S8 25 16 150 7.8 0.052 S9 30 18 150 7 0.046

When experiments are repeated

4.3: Effect of Welding Parameters on Tensile Strength for S/N Ratio

4.2.1 Tool Speed
The effect of tool speed on the Tensile strength values is shown in Fig. 4.3 for S/N ratio. Its effect is increasing with increase in tool speed up to3080 RPM. So the optimum tool speed is level 2 i.e. 3080 RPM.
4.2.2 Feed Rate
The effect of feed rate on the tensile strength values are shown in Fig. 4.3 for S/N ratio. Its effect is decreasing with increase in feed rate. So the optimum feed rate is level 1 i.e. 20mm/min.

4.2.3 Shoulder Diameter
The effect of parameter shoulder diameter on the tensile strength values is shown in Fig. 4.3 for S/N ratio. Its effect is increasing with increase in shoulder diameter. So the optimum depth of cut is level 3 i.e. 20 mm.

Fig. 4.4: Effect of Welding Parameters on Tensile Strength for Means
4.3 ROCKWELL HARDNESS TEST
The Fig.4.5 and table 4.8shownsurface joint hardness (HRB) for nine specimens at different parameters such as feed rate, transverse speed and shoulder diameters.The graph shown the maximum and minimum value of hardness at welding joint on different parameters such as feed rate, transverse speed and shoulder diameters.

Table 4.8: Rockwell hardness No. of the Specimens for Single Sided