From the following numbered list of characteristics, decide which pertain to (a) precipitation hardening, and which are displayed by (b) dispersion strengthening.
(1) The strengthening mechanism involves the hindering of dislocation motion by precipitates/particles.
(2) The hardening/strengthening effect is not retained at elevated temperatures for this process
(3) The hardening/strengthening effect is retained at elevated temperatures for this process
(4) The strength is developed by a heat treatment
(5) The strength is developed without a heat treatment
(a) 1,3,5 (b) - 1,2,4
(a) 3,5 (b) 1,2,4
(a) 1,2,4 (b) 3,5
(a) 1,2,4 (b) - 1,3,5
(a) - 1,3,4 (b). 1,2,5
