Properties of interfaces between iron-group metals (Fe, Co, Ni) and HfC via first-principles modeling

Metal carbide ceramics offer potential as protective coatings for iron-group metals M (Fe, Co, and Ni) because of its favorable physical, chemical, and mechanical properties. We present a computational study to evaluate the adhesion of hafnium carbide coatings on iron-group metals substrates based on density functional theory. We consider the Fe(110)/HfC(100), Co(111)/HfC(100), and Ni(111)/HfC(100) interfaces and focus on the magnetism, adhesion, and bonding of C-site and Hf site interfaces. The C-site interfaces have the largest adhesion, forming polar covalent/ionic mixed bonds. The calculations reveal that the work of adhesion increases on passing from iron to nickel (Fe < Co < Ni). Our results suggest that the presence of a metallic acceptor and a carbide donor insures good adhesion between the two components.