ICMCTF 2026 Session PP1-1-MoM: PVD Coatings and Technologies I

Sputter-deposited molybdenum disulfide (MoS₂) coatings are widely utilized in aerospace applications, primarily due to their exceptional reliability and ultralow friction in vacuum environments. However, the unique structure of MoS₂ often leads to high porosity in sputtered coatings which can significantly compromise wear life and accelerate film oxidation. To address these challenges, engineers typically engage in costly process development, varying deposition parameters to maximize film density with limited available heuristics. This process development is also equipment specific and must be repeated when a process needs to be transferred.

This study explores how the kinetic energy of species impacting the substrate during the growth of MoS₂ films influences their porosity. We employ Monte Carlo simulations using both SRIM (Stopping and Range of Ions in Matter) and SIMTRA (Simulating the Transport of Atoms from the Source to the Substrate) to analyze the contributions of both sputtered atoms and backscattered neutrals. By correlating these findings with nanoindentation hardness, we gain insights into how deposition dynamics affect coating porosity. Additionally, we compare the simulation results to in-situ measurements made with a Retarding Field Energy Analyzer (RFEA) positioned at the substrate. Our findings reveal the energy flux necessary to produce dense coatings, which can be used in combination with a RFEA to provide essential feedback for process development. This approach has the potential to both greatly accelerate process transfer and enhance the film performance of existing MoS₂ processes.

Sandia National Laboratories is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.

The presentation "HiPIMS and Digitalization: Increasing Efficiency in Machining" shows how modern digitalization and innovative coating technologies accelerate the development of HiPIMS coatings for cutting tools.

The focus is on using a HiPIMS coating system “CC800 HiPIMS,” for which a digital twin model exists that captures and analyzes large amounts of data.

Machine data are first collected via an OPC-UA interface, persisted in a database, and then transferred into the digital twin. This allows simulation results to be quickly integrated into process development. Consequently, only a few validation experiments are needed, saving time and resources. The simulation-optimized HiPIMS process parameters enable the deposition of coatings that are denser and harder than ever before. These were tested on cutting tools and achieved better results than previous layers.

Overall, the talk demonstrates how the combination of HiPIMS technology and digitalization increases efficiency in coating development, improves product quality, and strengthens competitiveness in high-performance machining.

The conceptual simplicity of reactive magnetron sputtering facilitates the description of global trends in process curves characteristic of reactive magnetron sputtering. However, achieving a quantitative description of these trends through simulations remains far more challenging, as the critical bottleneck of every modelling effort lies in the determination of accurate input parameters. Following a brief introduction to the RSD model, this paper provides an overview of several experimental methodologies designed to extract the parameters essential for its implementation. A central parameter in any thin-film deposition technique is the deposition rate. While its determination in metallic mode is relatively straightforward, the task becomes substantially more complex in poisoned mode due to the limited availability of sputter yield data for oxides. Our experiments reveal that in poisoned mode sputter yields exhibit a pronounced dependence on process conditions. Monte Carlo simulations, moreover, uncover a remarkable material-independent correlation between reported partial yields for oxides and experimentally measured yields in poisoned mode. Another crucial quantity, the ion-induced electron yield, can only be reliably determined experimentally, even for metals. By employing empirical scaling laws, however, it becomes feasible to estimate these yields under poisoned-mode conditions. The strong influence of chemisorption on the electron yield explains the discharge voltage behaviour in metallic mode. The influence of chemisorption on target poisoning emerges as the next major challenge, particularly as a novel strategy to control the reactive sputtering process exposes discrepancies between the current formulation of the model and experimental observations. Nevertheless, this measuring strategy provides compelling evidence that the RSD model’s prediction of double hysteresis behaviour is fundamentally correct.

Thermal barrier coatings (TBCs) are essential for extending the lifetime and efficiency of components exposed to extreme thermal environments, particularly in aerospace and energy systems [1-2]. Yttria-stabilized zirconia (YSZ) remains the benchmark topcoat material due to its low thermal conductivity, high fracture toughness, and outstanding thermal stability [1-4]. The performance of these coatings is strongly governed by the stabilization of the metastable tetragonal phase, which depends on both yttria content and deposition conditions [5].

In this study, YSZ thin films were deposited by dual-target reactive magnetron sputtering (Zr + Y) under an Ar/O₂ atmosphere. A parametric analysis was conducted to evaluate the effects of oxygen flow rate, substrate position, scanning amplitude, and yttrium doping level (expressed as Y₂O₃ content) on film growth, chemical composition, and crystalline structure.

Physicochemical and mechanical characterizations were performed using X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and nanoindentation. The optimal yttria content (Y₂O₃) was found to be ≈ 2.9 mol%, ensuring stable tetragonal phase formation.

Furthermore, the thermal stability of the prepared coatings was assessed through annealing cycles at 500 °C, 750 °C, and 1200 °C. The study aims to evaluate the stability of the tetragonal phase at elevated temperatures and to investigate the microstructural evolution of YSZ thin films.

This work establishes a multi-parameter optimization strategy for YSZ thin films, contributing to the design of next-generation TBCs with improved structural integrity and reliability in harsh service conditions.

MAX phases are a unique class of nanolaminated compounds that combine metallic and ceramic properties, offering excellent electrical and thermal conductivity together with remarkable resistance to creep, oxidation, and corrosion. These characteristics make them highly attractive as protective and functional coatings for next-generation hydrogen technologies. However, conventional sputtering techniques struggle to provide suitable growth conditions at reduced synthesis temperatures, often leading to phase instability and the formation of competing phases. Despite more than two decades of research on Ti–A–C (A = Si or Ge) MAX coatings [1,2], it has yet to be achieved to deposit them under less harsh, more practical conditions. To address this issue, Ti₂-A-C (A = Si or Ge) thin films were deposited by cathodic arc evaporation (CAE) and high-power impulse magnetron sputtering (HiPIMS) of metallic TiA (A = Si or Ge) targets in reactive Ar/C₂H₂ plasma atmospheres. To understand the relationship between deposition parameters, chemical composition, and phase formation, the resulting films were comprehensively characterized using high-resolution techniques, including ToF-ERDA-calibrated GD-OES, 2D-BBXRD, and t-CSXRD measurements. Subsequently, these results are correlated with application near electrochemical tests. Overall, these analyses demonstrate, for the first time, that Ti₂-A-C MAX-based coatings can be successfully synthesized by reactive CAE and HIPIMS at temperatures as low as 550 °C and rise their potential for use cases in hydrogen technologies.

[1] Emmerlich J, Palmquist J-P, Högberg H, Molina-Aldareguia JM, Hultman L. Growth of Ti3SiC2 Thin Films by Elemental Target Magnetron Sputtering. J Appl Phys. 2004;96: 4817. doi:10.1063/1.1790571

[2] Högberg H, Eklund P, Emmerlich J, Birch J, Hultman L. Epitaxial Ti2GeC, Ti3GeC2, and Ti4GeC3 MAX-phase thin films grown by magnetron sputtering. J Mater Res. 2005;20: 779–782. doi:10.1557/JMR.2005.0105

Transition metal nitride (TMeN) coatings deposited by physical vapor deposition (PVD) are often subjected to high residual stress, which may induce delamination and failure of coatings. Introducing a metal interlayer between the coating and substrate is one of the common approach to relieve residual stress. In our previous studies, we proposed an energy-balance model to quantitatively evaluate the energy relief efficiencies of ZrN/Ti, ZrN/Zr [1] and TiN/Ti [2] coatings. With the growing demands for multilayer structures, optimizing the thickness ratio between coating and the metal interlayer for the effective relief of stress and stored energy has become essential in improving coating performance. Therefore, this study aims to evaluate the thickness ratio between coating and interlayer using TiN/Ti/TiN/Ti as a model system. Quadlayer coatings with different TiN/Ti thickness ratios were deposited on Si substrates using DC unbalanced magnetron sputtering. Residual stress was measured by both laser curvature measurement and the average X-ray strain methods. Subsequently, the stored elastic energies of the coatings with different architectures were calculated. Using the previously proposed energy-balance model, the energy relief efficiencies of specimens with various TiN/Ti thickness ratios could be estimated. Accordingly, the effect of TiN/Ti thickness ratios on stress and energy relief could be accessed. Based on the results, the previous energy-balance model can be extended from bilayer to quadlayer coatings.

Keywords: Energy relief, energy-balance model, quadlayer coatings, average X-ray strain methods