Plane strain fracture toughness of scandium doped Al–6Mg alloy

Microstructure‐texture‐fracture toughness property correlation in annealed Al‐6Mg alloy with minor scandium and zirconium additions

“…11). These are supposed to be Al 3 Sc precipitates which are known to form in aluminium alloys containing scandium 7,8 . The morphology demonstrates that the coherent precipitates of Al 3 Sc are needle shaped in their early stage.…”

“…4). These PSBs are known to adversely affect the fatigue crack growth resistance 7 . Thus the existence of strong Goss component is deleterious to FT of the alloy.…”

“…When 0.2% Sc is added to Al-6Mg alloy, the precipitates of Al 3 Sc are seen to form. 7 High-resolution micrograph shows the presence of fine needles of 10 nm size surrounded by strain field (Fig. 11).…”

“…Presence of precipitates in the microstructure of an alloy influences the active slip systems and is expected to modify the profile of r-values. 6,7 It is observed that in some cases presence of coherent precipitates reduces anisotropy where as in some other cases precipitation phenomenon has not altered the r-value profile at the same level of precipitation strengthening. It is conjectured elsewhere that both nature and habit of precipitates have direct bearing on in-plane anisotropy and hence FT although there may or may not be any change in texture.…”

“…The strain dependence of r ‐value, characterising anisotropy in metals and alloys is strongly related to evolution of texture and microstructural condition. Presence of precipitates in the microstructure of an alloy influences the active slip systems and is expected to modify the profile of r ‐values 6,7 . It is observed that in some cases presence of coherent precipitates reduces anisotropy where as in some other cases precipitation phenomenon has not altered the r ‐value profile at the same level of precipitation strengthening.…”