Issue 37

C. Patil et alii, Frattura ed Integrità Strutturale, 37 (2016) 325-332; DOI: 10.3221/IGF-ESIS.37.43 328 Figure 3 : Brinell hardness Testing Machine. The FSW specimen was mounted on to the machine and the machine was loaded with load of 250 kgf for time of 20seconds and then removed. The resulting depth of impression was measured by the help of a microscope as shown in Fig. 4. Figure 4 : Microscope with depth of impression. A chart was then used to convert depth of impression to Brinell hardness number. All friction stir welded samples for different weld parameter were tested for Brinell hardness and the impression converted into BHN is shown in Tab. II for various FSW weld parameter. In Tab. II, sample number A to G presents FSW joints of similar alloys AA7075T 651 and sample number A1, A4 presents FSW joints of dissimilar alloys AA7075T 651 - AA6061T 6 . B1, B2 represents similar and dissimilar joints of TIG welding respectively.