Interstitial Solid Solutions. Austenitic steels can be formed by the interstitial solution of alloying elements into the tetrahedral sites of the iron FCC unit cell. Show all work and use sketches where appropriate. (a) What is the maximum theoretical concentration (as an atomic %) of alloying elements in the tetrahedral sites of the iron FCC unit cell.
(b) Assuming the alloying element is carbon. Calculate the maximum theoretical weight concentration (as a weight %) of carbon in the tetrahedral sites of the iron FCC unit cell.
(c) Assume that carbon will actually only fill 1/2 of the available tetrahedral sites in FCC iron. Calculate the concentration of vacant tetrahedral sites (per m®) for FCC iron if it has a lattice parameter of 0.357 nm.