Consider a lead-tin alloy that has the composition 20wt% pb – 80wt% sn. the temperature is 180°c. (i) what (mass) fraction of the alloy is in the  phase, and what fraction is in the  phase? (

Consider a lead-tin alloy that has the composition 20wt% pb – 80wt% sn. the temperature is 180°c. (i) what (mass) fraction of the alloy is in the  phase, and what fraction is in the  phase? (ii) what (mass) fraction of the alloy consists of primary (proeutectic) , and what fraction of the alloy has a eutectic microstructure? (iii) what mass fraction of the alloy is accounted for by the  that is present in the solidified eutectic material?