M. Vivas et al., DETERMINATION OF PRECIPITATE STRENGTH IN ALUMINUM-ALLOY 6056-T6 FROM TRANSMISSION ELECTRON-MICROSCOPY IN-SITU STRAINING DATA, Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties, 76(5), 1997, pp. 921-931
The transmission electron microscopy in-situ straining technique is em
ployed to measure the breaking angles of strengthening precipitates in
aluminium alloy 6056-T6 as they are sheared by dislocations. The expe
rimental determination of the character of bowed dislocation segments
when dislocations are pinned on precipitates allows us to calculate th
e corresponding line tensions. From this, the maximum forces F-m that
precipitates can sustain before being sheared by dislocations are dedu
ced. It is suggested that F-m may be regarded as a quantitative parame
ter which includes the effects of the various strengthening mechanisms
operative in precipitation-hardened alloys. An attempt is made to rel
ate the maximum force calculated from in-situ straining data to the ma
croscopic yield strength of the material.