In the Fe–Fe2Nb system, at 1373°C, of 3% Nb, liquid of 12% Nb and of 27% Nb are in equilibrium. At 1210°C, of 1% Nb, of 1.5% Nb and of 27% Nb are in equilibrium. At 961°C, of 0.4% Nb, 􀀀 of 0.7% Nb and of 27% Nb are in equilibrium. All compositions are in atomic%. The melting point of Fe is 1535°C and of Fe2Nb (33.3 at.% Nb) is 1627°C. The phase is stable over a composition range of 27 to 33.3 at.% Nb, (i) Draw an approximate phase diagram for this system. (ii) Write down the invariant reactions in the system, giving their names. (iii) What is the fraction of 􀀀 in an alloy with 10% Nb at 960°C?