Synthesis and mechanical characterization of electrodeposited multilayer structures in the Fe-P system
Timo Müller, Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, AustriaAndrea Bachmaier, Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, AustriaThomas Schöberl, Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, AustriaReinhard Pippan, Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, Austria
Lamellar structures on the nanometer scale are good candidates to combine high strength and ductility. A well-known example is the pearlitic structure of steels which is used in manifold engineering applications. In this work, another type of nanolamellar structures consisting of alternating crystalline and amorphous layers was investigated. The variation of the layer thickness was used as a tool to tailor the mechanical properties. Amorphous/crystalline multilayer structures of Fe-P alloys were prepared electrochemically, since Fe-P electrodeposits are known to show a crystalline or an amorphous structure depending on their phosphorus content which can be adjusted via the deposition current. The individual layer thickness was varied from about 250 nm down to a few nanometers whereas the total nominal thickness of the deposit was kept constant. Hall-Petch behavior was observed concerning microhardness for layers larger than 15 nm, whereas a hardness plateau was obtained for thinner layers. Nanoindentation was performed both parallel and perpendicular to the surface of the substrate. Besides, micromechanical experiments were used to get further information about the mechanical properties of these materials.