Digital Library

Key aero-engine components are subject gas stream temperatures above the melting point of their metal alloy, a demanding environment that can only be survived thanks to the combination of cooling and protection from Thermal Barrier Coatings (TBCs). Electron-Beam Physical Vapour Deposition (EB-PVD) can deposit TBCs with a unique columnar microstructure that is strain compliant and ideal to survive in cyclic, high-strain, high-thermal load environments, such as those of the rotating parts of the high temperature turbine. TBCs based on yttria-stabilised zirconia (YSZ) are tough and effective, but they are also susceptible to sintering and chemical attack by calcium magnesium alumino-silicates (CMAS) at higher operating temperatures, which are required to improve engine efficiency. Rare Earth Zirconates (REZ) are postulated as potential YSZ substitutes due to their higher resistance to CMAS attack, lower thermal conductivity and high phase stability, although they also exhibit a lower toughness and more manufacturability challenges. This work focuses on two known systems (Gadolinium and Lanthanum Zirconate – GZ and LZ), a novel system (Neodymium Zirconate - NZ), and YSZ references and explores co-evaporation and use of mixed-ingot oxides to overcome the manufacturability challenges in EB-PVD. The columnarity, general microstructure, and uniformity of all systems has been evaluated, with special emphasis on the LZ system that, traditionally, results in heterogeneous composition and lack of columnarity. The use of simple computer models has helped to understand the underlaying mechanisms of these challenges. The performance of the resulting TBCs has been evaluated for CMAS attack and high velocity erosion, considering depth of infiltration and reactive formation of protective compounds for the former, and erosion rates, damage mechanisms and proposed erosion testing alternatives for the latter. Overall, NZ seems a promising system on-par or better than GZ.

https://doi.org/10.14332/svc25.proc.0011

Since the 1960s, pioneering work in Electron Beam Physical Vapor Deposition (EB-PVD) of metal strips has led to the installation of numerous pilot and production plants worldwide. However, the demand for ongoing development in a variety of application areas remains strong. To meet the changing challenges of modern industry, multifunctional equipment is essential. In 2000, the innovative inline vacuum coating plant for sheets and metal strips called MAXI was set into operation at Fraunhofer FEP in Dresden, Germany, to address global research and development needs. This modular system, comprising eight chambers, allows for the sequential execution of different process steps and offers the flexibility to operate in both sheet-to-sheet and roll-to-roll modes. This results in more efficient, faster, and easier progress during the early stages of development, as well as a smoother process transfer for the upscaling. In celebration of MAXI's 25th anniversary, we will provide an overview of the diverse research projects realized over the years — from metallurgy and semiconductor applications to cutting-edge solutions for today’s energy technologies. Additionally, we will discuss current modernization activities.

https://doi.org/10.14332/svc25.proc.0001

Physical Vapor Deposition (PVD) is a coating process that is well known to be environmentally friendly. Compared with other thin film coating processes it does not create chemical harmful waste or harmful emissions that pollutes air and water. However, there are other factors that make PVD not as sustainable as it looks at first sight. For example: high energy consumption, inefficient use of resources, material and samples waste. So, what can we do to make PVD more sustainable? PVD energy consumption mainly comes from cooling, pumping and heating stages during the coating process. The aim of much research is to find ways to avoid heating of substrates and chambers, and to reduce coating time via improved surface engineering. This talk will focus on the tools that are available to reduce pumping time and make processes more efficient - which also entails a cost reduction. For material waste, better target use and more efficient sputtering makes a positive impact on cost reduction and helps with certain global material shortages. Having a deep understanding of the magnetic design of the magnetron source will have a significant impact on these matters. Another factor that is often not considered is the extra energy use that comes from failed runs that result in substrate and coating waste. These are commonly caused by contamination that results in coating defects and therefore production scrappage. In this case we can prevent it from two different approaches: choosing the correct deposition technology for the application and monitoring the vacuum conditions during production to detect potential problems beforehand or track past failures and learn from them. Different magnetron technology will be presented and sensors and devices for monitor and control.

In this talk, a variety of products and technologies are going to be presented to explore how can PVD be more sustainable, more efficient and therefore also get a reduction in production costs.

https://doi.org/10.14332/svc25.proc.0013

The hydrogen market is growing rapidly. The industry is developing for technical solutions for hydrogen generation and hydrogen-based electricity generation for mobile and stationary applications, and universities and institutes are investigating solutions for the long term. Today’s challenge is to bridge the gap between current low to medium technology maturity level and market demand: how to be able to produce hydrogen on large scale and how to scale fuel cell production to high volumes? IHI Hauzer is working on this challenge for many years, developing low cost coatings to supply to the market either by machine solutions and coating services. Key components of electrolyzers and fuel cell stacks like bipolar plates, PTL sheets and CCM’s need high quality coatings to enable good catalyst performance, good electrical conductivity and good corrosion properties. For bipolar plates and PTL sheets, Hauzer has developed coatings based on PVD technology. In the presentation the actual state of the art will be addressed, including the current status of market introduction and our expected further roll-out within the next years. For PVD, the current main challenges related to machine and process solutions for high speed inline coating will also be addressed. We will further address the requests from the market especially the electrolyzer business and give an outlook about possible solutions to serve these demands.

https://doi.org/10.14332/svc24.proc.0044

Carbon-based electrochemical sensors for aqueous solutions are typically screen-printed on rigid and flexible substrates. However, most of those electrode materials are poorly suited for non-aqueous solvent electrochemistry due to their binder system. This limitation spurs interest in exploring alternative carbon-based electrode materials. While boron-doped diamond (BDD) electrodes are inert to such conditions, high processing temperatures and complex scalability make them cost prohibitive for low-cost disposable sensing applications. Addressing this, we investigate the viability of a nitrogen-incorporated tetrahedral amorphous carbon (ta-C:N) as an effective solution. Ta-C:N is a highly sp³-bonded carbon n-type semiconductor with electrochemical properties comparable to BDD such as low background current and noise, and good microstructural stability at positive detection potentials. Ta-C:N thin films are synthesized by physical vapor deposition (PVD). As a result, low processing temperature, commercially available, industrial-scale systems and processes are available for potential roll-to-roll production. Here, we have developed and fabricated a ta-C:N 3-in-1 style electrochemical sensor on a rigid silicon substrate. The electrode configuration included a ta-C:N based counter, working, and reference electrode. The amorphous carbon was directly deposited onto the substrate by laser controlled pulsed cathodic vacuum arc (Laser-Arc) and patterned by a standard liftoff photolithography process. While evaluating the same electrode material on flexible polyimide substrates, we observed cracking and delamination after initial electrochemical testing. As a result, further surface engineering was required to withstand such conditions. Hence, this study also investigates different substrate pretreatments and/or interlayers for ta-C:N on polyimide and their effect on the electrical and electrochemical performance of the functional ta-C:N top layer compared to ta-C:N on conductive silicon.

https://doi.org/10.14332/svc24.proc.0046

The optical characteristics of thin films can display remarkable sensitivity to the refractive index of the constituent material, making phase-change materials particularly interesting for sensing purposes. Among these materials, vanadium dioxide (VO₂) stands out for its exceptional performance. It undergoes significant shifts in refractive indices and electrical conductivity during its transition from insulator to metal, which occurs at approximately 70 °C, a temperature not far from room temperature. The versatility of VO₂ lies in its ability to undergo phase transition triggered by various stimuli including heat, light, and electric fields, enabling a broad range of sensor applications. One effective approach involves observing the interaction of light and infrared radiation with VO₂ films and analyzing the resulting alterations in amplitude and polarization states. These changes can be precisely measured using signal modulation and amplification techniques, facilitating the development of miniaturized sensors. Films as thin as 50 nanometers can be utilized in this setup. In this study, we outline and demonstrate methodologies employing VO₂ thin films to detect subtle fluctuations in temperature and electrical currents. The sensing mechanism capitalizes on the generation of heat through mechanical means, such as friction, or electrical heating via the Joule effect. The paper will discuss theoretical limits and provides proof of concept demonstrations.

https://doi.org/10.14332/svc24.proc.0045

In-line coating systems are ideally suited for high volume production applications over a wide range of substrate sizes and geometries. Parts are fed in on one side of the coating plant, run through the various process chambers and are finally released to atmosphere at the other end of the coating system.
PVT has designed and developed different in-line coating systems that are ideally suited for Physical Vapor Deposition (PVD) coating of bipolar plates for fuel stacks and electrolyzers in high volume. In-line coating systems are characterized by the ability to perform each step of the coating process in its own dedicated vacuum chamber. Process chambers are isolated from each other by large area transfer valves.
Multi-layer film stacks are deposited in a highly productive process cycle. PVT will present its newest in-line system which is extremely productive and versatile using magnetron sputtering and HiPIMS.
PVT is offering coating service with this in-line system for development and pilot production applications. Properties of the different coatings deposited by HiPIMS and dual magnetron sputtering are presented such as ICR – values and corrosion data.

https://doi.org/10.14332/svc24.proc.0043

Developing precise Lead-Selenide (PbSe) gratings with narrow slots is essential for the advancement of mid-infrared (MIR) technologies used in spectroscopy, thermal imaging, and environmental sensing. A major hurdle in fabricating these components is the tendency for increased irregularities and reactive ion etching (RIE) delays in the etched profiles as the slot width becomes smaller. This talk identifies the accumulation of charge on non-conductive photoresist as the primary source of these irregularities. By applying a conductive copper layer, we can neutralize this charge, allowing for the successful etching of gratings with significantly enhanced profiles and slot widths reaching as low as 0.7 μm. This breakthrough not only boosts the sensitivity and resolution of MIR devices but also paves the way for novel applications in areas such as security and healthcare.

https://doi.org/10.14332/svc24.proc.0048

Modern society runs on seamless mobile connectivity. Yet, the wide commercial adoption of low-emissivity (low-E) windows introduces significant problems in the transmission of mobile signals, which is further exacerbated by the global adoption of 5G networks, particularly mid to high-band 5G frequencies. This presentation introduces a production-line integrated and cost-competitive low-E manufacturing technology enabling mobile signal penetration of low-E windows while maintaining optical and thermal performance. Core technology leverages lithography and is fully compatible with the throughput of existing Low-E production lines. Final low-E products enable 5G transmission across low and high frequency bands while maintaining superior visual aesthetics with invisible pattern lines under any angle and any lighting conditions. Furthermore, the technology meets low-E’s durability criteria, including mechanical alcohol wiping durability and thermal tempering tests. Supported by NSF funding, this project aims to commercialize next-generation mobile signal penetrating Low-E products at scale and cost competitively for global adoption in architectural applications to enhance indoor connectivity in the 5G era.

https://doi.org/10.14332/svc24.proc.0021

Atomic Layer Deposition (ALD) is now a well-established process broadly used in the manufacture of leading-edge semiconductor chips. ALD is required for this application due to its high level of precision and ability for conformal deposition of pinhole-free coatings on complex surfaces. These same coating attributes are highly desirable in other applications, such as thin film encapsulation, on the large area substrates used in the display and photovoltaic industries. But to date, scaling of ALD processes to such large substrates, with sufficient throughput and at the low cost required for these applications, has been elusive. In this work, a novel Spatial Plasma Enabled ALD (S-PEALD) process is demonstrated that offers the economic scalability of ALD to these large area substrates. The use of a simple DC plasma source, enabled by the use of spatial processing, allows plasma generation over the multi-meter distances required for these substrate sizes. Meanwhile, a novel method for spatial precursor separation provides the means to utilize a simple, compact, and rapidly moving coating head for executing the ALD cycle. In combination with a mixed oxide barrier material, a process is demonstrated that provides a path to the in-line deposition of OLED-quality barrier coatings on multi-meter substrates, with a takt time of less than one minute.

https://doi.org/10.14332/svc24.proc.0022