Citation:
Wang H, Colegrove P, Mayer HM, et al., (2010) Material constitutive behaviour and microstructure study on aluminium alloys for
friction stir welding. Advanced Materials Research, Volume 89-91, pp. 615-620
Abstract:
The material constitutive behaviour and microstructure of Aluminium alloys 6082
and 7449 were studied with the Gleeble hot compression test. The novel aspect of
the work is that the testing was done at high strain-rates and at temperatures
within 5 K of the solidus. The results indicated that the strength was
maintained up to near solidus temperatures, with no dramatic strength reduction
being observed. There was however, a distinct change in the slope observed with
the 7449 results around 720 K. The experimental results were then fit to the
Zener-Holloman equation, which describes the relationship between the material
flow stress, temperature and strain-rates. The material microstructure of the
hot compression test samples was analysed, and the averaged grain size was
calculated to compare with friction stir weld nuggets. This will be used to
infer the processing conditions that exist in the dynamically recrystallized
weld nugget. Finally, a simple model was used to understand how processing
conditions affected the deformation behaviour.