Issue 62

A. Mishra et alii, Frattura ed Integrità Strutturale, 62 (2022) 448-459; DOI: 10.3221/IGF-ESIS.62.31

bigger grains, which are thermally impacted by heat and rotating pin, are seen in the TMAZ. Fig. 8 shows the microstructure images in the Stir Zone (SZ). Due to dynamic recrystallization caused by friction stir welding, the stir zone is characterized by extremely small, equi-axed grains that are far smaller than those seen in the Heat Affected Zone (HAZ) and TMAZ. It has been noted that the particle size in HAZ is significantly larger than the grain size of the base substrate and is about twice as coarse as the grain size of the base metal as observed from Fig. 9.

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Figure 7: TMAZ Microstructures.

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