Synthesis of novel magnetron sputtered nanocomposite coatings via external nanoparticle injection
Qingqing Fu, Universität Duisburg-Essen, Duisburg, DeutschlandDavid Kokalj, Technische Universität Dortmund, Dortmund, DeutschlandDominic Stangier, Technische Universität Dortmund, Dortmund, DeutschlandEinar Kruis, Universität Duisburg-Essen, Duisburg, DeutschlandWolfgang Tillmann, Technische Universität Dortmund, Dortmund, Deutschland
Nanocomposite coatings, composed of at least two nanoscale phase-separated domains exhibit enhanced mechanical, tribological, and anti-oxidation properties as compared to microcomposites and monolithics [1,2]. Basically, there are three different ways to generate nanocomposite structures using PVD technology. One possibility is to select two metals, which at certain levels reveal a miscibility gap and form mixed crystals of different structures. Besides, metals with widely diverging nitrogen affinities are more feasible to form a nanocomposite structure. This composite structure consists of a nitride-affinitive metal and a metallic component. The most widely used mechanism is based on the use of a nitride-forming transition metal, which is nanocrystalline sized and embedded in an amorphous matrix.
TiN and CrN monolithics reveal outstanding mechanical and tribological properties and are thus used for several industrial components. However, the TiN/CrN nanocomposite structure cannot be realized by means of reactive magnetron sputtering processes, since a single-phase crystalline CrTiN is synthesized.
In this work, novel nanocomposite coatings, in which cubic TiN nanoparticles are embedded in a sputtered CrN matrix, will be synthesized and investigated. This innovative coating can be realized by injecting TiN nanoparticles, synthesized by reactive arc discharge, into a PVD chamber where the CrN matrix is deposited simultaneously. To transfer the nanoparticles that are synthesized in an atmospheric pressured gas into a high vacuum PVD chamber, an aerodynamic lens system will be utilized and optimized during the process, whereby specific technical requirements such as the desired particle mass and maximum gas flow rates into the PVD chamber will be fulfilled and the corresponding results will be demonstrated. Moreover, since the deposition of PVD thin film takes several hours, depending on the selected material and coating thickness, the arc reactor applied to synthesize TiN nanoparticles will be optimized and stabilized over a prolonged period. The deposited TiN nanoparticles as well as the novel synthesized TiN/CrN nanocomposite coatings will be analyzed and compared to conventional single phase TiCrN thin films.
Acknowledgment: This research is financially supported by the Deutsche Forschungsgemeinschaft (DFG) with the Project number 382368006
References
[1] Patscheider J 2003 MRS Bull. 28 180–3
[2] Kiesler D, Bastuck T, Kruis F E 2015 J Nanopart Res 17 121