Discontinuous Precipitation in Al-8% Mass.Mg Alloy under the Effect of Temperature1283
(a)
(b)
(c)
Figure 5. Microhardness (HV) evolution structural of
Al-8% mass.Mg alloy, homogeneised at 440˚C during 44 h,
quenched in ice, aged at 160˚C (a), at 220˚C (b) and at
270˚C (c).
to a continuous precipitation. Continues precipitation is
favoured at high and low temperature, while discontinu-
ous precipitation dominates at intermediate temperatures.
High temperatures accelerate relatively the diffusion
process and the mechanism S is more dominating in dis-
continuous precipitation. Hardening was observed at all
temperatures of ageing, however the extension of ageing
time of bearing led to a hardness fall.
5. Acknowledgements
The authors gratefully acknowledge the financial support
by the M.E.S.R.S Ministry for the Higher Education and
the Requirend scientist of Algeria under research labo-
ratory LARHYSS, University of Biskra.
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