4 An Application from a Defect—A Friction …
135
Fig. 4.2 Zones in FSWed workpiece
specific zones, namely the nugget zone (NZ), thermo-mechanically affected zone
(TMAZ), heat affected zone (HAZ), and base material (BM). The NZ is formed by
the pin where the heat generation is mainly due to friction, as well as the mechanical
mixing of the material. This brings about finer, equiaxed, and recrystallized grains at
the NZ. TMAZ is next to the NZ, where the effect of heat is noticeable, but minimal
mechanical deformation leads to coarser grains compared to that in NZ. The HAZ
is entirely affected by the heat generated during the process. Since, in FSW, heat
generation is well below the melting point temperature of the workpiece material,
the HAZ zone is much smaller compared to that formed in fusion welding techniques.
4.1.4 FSW Terminologies
The following terminologies are the most commonly used in describing aspects of
the FSW process. They are shown in Fig. 4.3.
Fig. 4.3 a, b Showing different terminologies used in FSW
135
Fig. 4.2 Zones in FSWed workpiece
specific zones, namely the nugget zone (NZ), thermo-mechanically affected zone
(TMAZ), heat affected zone (HAZ), and base material (BM). The NZ is formed by
the pin where the heat generation is mainly due to friction, as well as the mechanical
mixing of the material. This brings about finer, equiaxed, and recrystallized grains at
the NZ. TMAZ is next to the NZ, where the effect of heat is noticeable, but minimal
mechanical deformation leads to coarser grains compared to that in NZ. The HAZ
is entirely affected by the heat generated during the process. Since, in FSW, heat
generation is well below the melting point temperature of the workpiece material,
the HAZ zone is much smaller compared to that formed in fusion welding techniques.
4.1.4 FSW Terminologies
The following terminologies are the most commonly used in describing aspects of
the FSW process. They are shown in Fig. 4.3.
Fig. 4.3 a, b Showing different terminologies used in FSW