Completed coordinated programmes
SPP 2074 - Fluid-free lubrication systems under high mechanical load
Short description:
In the research program Fluid-free lubrication systems under high mechanical load - SPP 2074, the friction and wear mechanisms due to the formation of transfer layers in tribological systems are being studied when lubricating with solid lubricants. For this purpose, the first step is to determine the system-specific supply processes of the solid lubricant as a function of the operating conditions (including temperature, pressure, sliding speeds) in order to be able to determine the requirements for the availability of solid lubricant in the contact area to be lubricated. Depending on the operating conditions, the lubricant and the contact partners in the highly loaded contact, the transfer processes will be clarified on this basis. Here, a distinction can be made between physical and chemical transfer processes, which enable the most durable transfer possible. Physical adhesion mechanisms can occur through a mechanical "clamping" of solid lubricant components with the surface, chemical mechanisms can be based on physisorption and chemisorption. The understanding should subsequently be used to synthesis systems for the supply and transfer of solid lubricants in highly stressed contact conditions.
In the sub-project "Fluid-free lubricated spur gears - tribological analysis and constructive design", self-lubricating hard coatings are being developed for use on gears. More detailed information is available here.
| Funding: | German Research Foundation (DFG) |
|---|---|
| Porject number: | SPP 2074 |
| Duration: | January 1, 2019 to December 31, 2021 |
High Power Pulsed Magnetron Sputtering (HPPMS) coating deposition and process understanding
Short description:
Project A1 is a subproject of the Transregional Collaborative Research Centre SFB-TR87 in its third funding phase. The project investigates basic mechanisms of the synthetic pathway for the production of hard coatings in high-performance plasmas. The validation and consistency of the methodology for the knowledge-based design of industry-relevant coating processes on complex substrates for a concrete stress collective will be completed in the third phase. One aim is to transfer the knowledge-based methodology for the process development of the multilayer Cr-Al-O-N coating concept to (Ti;V)-Al-O-N. During the validation, results from different models developed in the SFB are brought together. The results are transferred to low-temperature processes for plastic substrates. Another aim is to increase the adhesion between individual layers and to the substrate. Through research on the etching phase of the PVD process, A1 seeks to design plasma etching processes for steel and plastic substrates. The substrate temperature, which is crucial for adhesion, is measured online in the process phases with the new temperature sensor and the influence of residual stresses on adhesion is being investigated. Furthermore, the project determines theoretically ideal layer thicknesses and residual stresses that are implemented in A1 during coating production. The work will be extended by investigations of corrosive interactions, the influence on plastic degradation and adhesion wear. New evaluation methods for the interaction between polycarbonate melt and Cr-Al-O-N will be transferred to other plastics and coatings, and subsequently be validated. On the long run, the coating selection for extrusion can be predicted depending on the plastic, which is produced in knowledge-based plasma processes. Poster SFB-TR 87 A1
| Funding: | German Research Foundation (DFG) |
|---|---|
| Porject number: | SFB-TR 87 A1 - DFG TRR 87/3 |
| Duration: | July 1, 2018 to June 30, 2022 |
Influence of plasma properties on coating properties in pulsed high-performance plasmas
Short description:
The 3rd funding phase of the subproject C6 in the transregional collaborative research center SFB-TR 87seeks to validate process diagnostics methods that were developed in the 2nd funding phase. This aim is reached by transferring results from the Cr-Al-O-N system to (Ti;V)-Al-O-N. This will prove that the process development can be significantly shortened by using plasma diagnostics. At the same time, the incorporation of nitrogen into the coating, which is relevant for the coating development, is analyzed. In addition, the focus of the project is on the transfer and validation of the developed plasma diagnostic methods to production-ready process diagnostics. For the first time, also the cleaning effect of plasma etching is investigated diagnostically in order to increase the adhesion to steel and plastic substrates. For this purpose, the quality and effectiveness of plasma etching is correlated with plasma parameters and the substrate temperature in order to obtain the best possible plasma cleaning near the maximum permitted temperatures of the substrates. A further goal is the iterative development and validation of artificial neural networks (ANN). Here, the relationships between process and plasma, plasma and coating, and coating and system are considered. Overall, C6 contributes important work to overcoming the empirical approach to coating development using high-performance plasmas. Poster SFB-TR 87 C6
| Funding: | German Research Foundation (DFG) |
|---|---|
| Porject number: | SFB-TR 87 C6 – DFG TRR 87/3 |
| Duration: | July 1, 2018 to June 30, 2022 |
Excellence Cluster „Integrative Production Technology for High-Wage Countries“ - Project C3 „Multi-Technology Products“ – Test case „Optic“
Short description:
The aim of the research project was the development of a continuous process chain for the production of structured, optically functional plastic components. Laser technology was used to introduce structures in the micro- or nanometer range into the cavities of the injection molding tool. These were molded by brittle plastics, such as polycarbonate and polymethyl methacrylate, in the subsequent plastics processing process. By coating the laser-structured tool using the physical vapor deposition (PVD) process, it was possible to reduce wear and the adhesive force between the tool surface and the plastics. In addition, it was shown that laser structures can only be molded by modifying the surface with a suitable PVD coating. Without the additional coating, the structures break from the uncoated mold during demolding and, in contrast to the coated mold, the polymer sticks to the structures. The replication ratio could be improved by 20 to 30 % depending on the structure type. Poster EXC-128
In the transition phase, PVD sensor coatings are developed for temperature measurement. The focus is on metallic sensor layers, which are protected from wear by hard coatings, as well as on sensor coatings, which themselves consist of hard coatings. The sensor coatings are suitable for providing production data in real time. By combining them with a thermally sprayed heating conductor coating to create a sensor-actuator system, the coating systems can independently influence the temperature control of manufacturing processes. Poster EXC-128 transition phase
| Funding: | German Research Foundation (DFG) |
|---|---|
| Porject number: | EXC-128 |
| Duration: |
November 1, 2012 to October 31, 2017 November 1, 2017 to December 31, 2018 (transition phase) |
Influence of solid-liquid reactions in the brazing gap on joint properties and precision
Short description:
The aim of the project is to reduce the quantity of intermetallic compounds in the brazing seam and the effect of the heat treatment on the base material when joining hot work tool steels with a nickel based filler metal. Thus to improve the mechanical and thermal properties of the joint will be improved. In order to achieve this the grain growth will be reduced by an adapted temperature control and by electric current assisted brazing which results in accelerated and directed diffusion during brazing. Poster SFB 1120 – Teilprojekt A5
| Funding: | German Research Foundation (DFG) |
|---|---|
| Porject number: | SFB 1120 – Project A5 |
| Duration: | July 1, 2018 to June 30, 2022 |
Development of simulative approaches for specific developement of the properties of plasma sprayed coatings
Short description:
Project A10 deals with the tailored development of plasma-sprayed heat insulation coatings by means of numerical prediction. During atmospheric plasma spraying, not only process parameters but also disturbances influence process characteristics. As a result, the processes that occur during the transition of the coating building particles from the solid into the (partly) liquid state and from the (partly) liquid state into the solid state are also influenced. The correlation between the process parameters and the coating properties were successful in the first phase of the project, both numerically and experimentally. The focus of the second phase of the project lies on the analysis of disturbance-dependent process changes by means of modeling and simulation. The aim of the second phase is the prediction of the coating properties while taking into account the disturbances that occur in the real processes. Poster SFB 1120 – Teilprojekt A10
| Funding: | German Research Foundation (DFG) |
|---|---|
| Project number: | SFB 1120 – Teilprojekt A10 |
| Duration: | July 1, 2018 to June 30, 2022 |