An automotive engineer must select a material for a car frame that must (1) resist permanent deformation in a collision, (2) permit spot-welding that relies on high electrical conductivity, and (3) keep manufacturing cost low by minimizing expensive alloying elements. Considering how lattice structure affects mechanical and electrical properties, which material best meets all three criteria?
(a) Pure aluminum
(b) Iron containing 3 mass % chromium atoms substituted for iron atoms
(c) Iron containing 0.8 mass % carbon atoms in interstitial sites (medium-carbon steel)
(d) Aluminum containing 5 atom % zinc substituted for aluminum atoms