Development and Characterization of Zr‐Based Multi‐Component Nanocomposite Coatings Prepared Using Single Alloying Target

Nanocomposite coatings comprising multiple phases on the nanoscale are increasingly used for automobile engine systems as they offer high thermal stability, high hardness, and low coefficient of friction. Since it is not easy to fabricate alloying targets, multiple targets have been used to prepare conventional nanocomposite coatings, resulting in the need for complex equipment and processes. Therefore, single alloying targets with homogeneous compositions and high toughness will simplify mass production of nanocomposite coatings. In this study, amorphous alloys are introduced to prepare the alloying target because of their homogeneous composition, good mechanical properties, and design rules that are similar to those for nanocomposites. Multi‐component alloying targets comprising Zr, Al, Mo, and Cu are successfully prepared by atomization and spark plasma sintering, both of which are powder metallurgical processes. The targets with amorphous structure are subsequently heat‐treated in a vacuum at ≈800 °C to crystallize the microstructure and improve the mechanical properties for sputtering. This study is the first report on modification of the fracture toughness of Zr‐based intermetallic compounds by changing the grain size. Improved fracture toughness of these compounds with a specific range of grain size is obtained by heat treatment of the amorphous target.