Fig. 6 e (a) The effects of the applied stress during the SPS
process on the accumulated hydrogen volume per unit
weight at initial stage of the SPSed Al. Hydrogen generated
from hydrolysis of the SPSed Al in 10 wt. % NaOH solution
at room temperature. (b) BET specific surface area and
relative density of the SPSed Al as a function of the applied
stress during the SPS process.