Crack Paths 2006

320

300

280

260

240

220

200

1600

1800

2000

2200

2400

2600

Total Frictional Power(J/s)

during welding. Lower values of frictional power occur in two specific tool speed and

feed regimes, as is shown in Fig. 6.

Figure 5. Frictional power input versus tensile strength.

Figure 6. Frictional power as a function of tool rotational speed and feed rate.

The high speed and feed regime of low frictional power in Fig. 6 is centred around

600 rpm and 185 mm/min, while the low speed regime occurs below 300 rpm and 140

mm/min.

C R A CPKA T HE F F E C T S

From the relationships shown already it would be expected that there would be a

relationship between defects and tensile strength, and therefore between defects,

frictional power and the process parameters of tool speed and feed. These welds do