D.H. Lammlein PhD Dissertation - Vanderbilt University

Figure 119: Macrosection view of an unsupported, butt configuration weld made with a
100º conical tool (0.025” diameter snub-nose and 0.015” cupped nose recess) at
800rpm, 5.2 ipm, and a penetration depth of 0.11”.
Figure 120: Macrosection view of an unsupported, butt configuration weld made with a
100º conical tool (0.025” diameter snub-nose and 0.015” cupped nose recess) at
1000rpm, 10.4ipm, and a penetration depth of 0.11”. At this depth, unsupported welds
made with the conical tool begin to split and protrude at the root for some of the tested
weld parameters. The initiation of protrusion and splitting in the weld root at 0.110”
was deemed undesirable by the authors for the suggested applications. The experimental
matrix was therefore performed at 0.100” where this did not occur. It should be noted
however that the strength of the unsupported welds increased with depth beyond the
experimental matrix depth of 0.100”.
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